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September 2, 2008: Our Magnificent Moths

My captive caterpillar herd has diminished considerably as the summer has progressed, but a few keep eating away, in no hurry to enter the pupal stage in which they will spend the winter. Readers will perhaps remember my telling about their hatching and early care. This was fairly time-consuming as fresh leaves had to be gathered daily and the minute caterpillars transferred to them in their closed containers. Once they were placed in the mesh sacks that enclosed tree limbs, however – the cecropia on apple and the luna on birch – the chores became only a matter of empting the droppings (much more pleasantly called “frass”) every few days and watching them grow.

Even the frass has provided fodder for study with entomologists, as some species eject these small pellets with some force, sending them off the leaves on which the insects are feeding. This seems to be important, as the frass has been found to give off odors that attract predatory wasps, major enemies of the young caterpillars. Experiments have shown that up to 30 percent of caterpillars in some wild populations can be killed by these predators over just a few days.

The caterpillar is the second stage in the complicated process of the creation of a butterfly or moth. Although these beautiful insects in their adult lives drink mostly nectar, or in some cases, eat nothing at all, their larvae chew up and eat leaves in prodigious amounts. They are voracious feeders and many of them do considerable agricultural and garden damage, and are far better known in their caterpillar stages than as adults.

A caterpillar has a soft body that can grow rapidly until its skin is stretched to its limit. At that point, it forms a new skin under the old, which then splits and is cast off. Only the head capsule is hardened and it is equipped with tough sharp jaws for chewing leaves. Behind the mouthparts are the spinnerets, from which silk is emitted for various uses such as spinning cocoons, or threads for attachments or locomotion.

Most caterpillar bodies are made up of thirteen round segments. Behind the head are three sections of the thorax, each supporting a pair of small true legs, recognized as such because they are jointed and often have a claw at the end. These are retained when the caterpillar transforms into a pupa and eventually become the legs of the adult. Abdominal segments 3 through 6 and segment 10 usually bear a pair of fleshy, stubby little appendages called prolegs that are used for walking and clasping. Each proleg has a set of tiny hooks arranged in rings around the tip that allow it to hold on to almost any surface. People raising caterpillars are warned not to try to remove a tenacious caterpillar from a support, as its prolegs will sometimes actually tear off rather than release their grip.  During metamorphosis the prolegs disappear and the butterfly or moth emerges with only the six true legs.

The caterpillar has 4,000 muscles (humans have only 629) and move by contracting the muscles in its rear segments. This pushes fluid forward into the front segments and stretches them out. It then releases the hold of its rear prolegs and allows the back segments to catch up. Like all insects, caterpillars breathe through a series of small openings along the sides of their thorax and abdomen that branch into the body cavity through a network of tiny tubes.

A caterpillar has six tiny eyelets on each side of the lower portion of its head that are only capable of detecting light. As the larva develops and matures into an adult insect, these are replaced by more complex compound eyes that may consist of thousands of tiny independent photoreception units, each of which is made up of cornea, lens, and photoreceptor cells. Compared with mammal eyes, compound eyes have poor image resolution but they have a very large field of view and a good ability to detect any movement.

Probably the most famous and well-known caterpillar is the inchworm. Its body is slender and hairless, and many species have projections that help them mimic flowers, twigs or foliage. When in danger, some inchworms stand upright on their prolegs, making them resemble a twig. Inchworms have the three pairs of true legs at the front and only two pairs of prolegs on the rear segment, accounting for their strange gait of humping up their middle segments during locomotion. The adult moths of inchworms lay their eggs in the late fall, and after the eggs hatch the next spring, the caterpillars feed for four or five weeks and then burrow into the soil to make their cocoons. The adults emerge in November – the female moth is wingless and the inconspicuous male has a wingspan of about 1 inch — and the cycle begins again.

My caterpillars and the adult moths they will become are much more spectacular than the inchworms. The cecropia moths are beautiful creatures that often have wingspans up to 6 inches and their larvae measure at least 4 inches before they spin their cocoons. The lunas have pale green wings that end in long delicate tails, and their caterpillars are somewhat smaller, but still formidable. I also had a brief experience with a tomato hornworm – an even bigger caterpillar. Neighbors found their tomato patch pretty well stripped of leaves when they returned from vacation and were happy to share the only culprit we could find. I placed it on one of my plants and covered it loosely with netting for protection from birds, only to have it immediately disappear. These caterpillars bury under the dirt to pupate and transform into large hawk moths that are often mistaken for hummingbirds. I was sorry to lose it but perhaps the moths will visit my garden next year and I can be more careful. 


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August 26, 2008: The Other Songsters


Perhaps you have noticed in recent years that the sounds of the insects that sing in the late afternoon and evening these late summer days have diminished considerably as you walk around your yard or along a path in the out-of-doors. The cause in this case is not a noticeable decrease in the number of the insect singers, new invasive species that have displaced them, or even global warming. It is our own ears.

The fact is that insect listening is best done as a child. When we are young our hearing usually extends from around 30 Hz – a hertz is a unit of measurement based on one sound wave per second -- to as high as 20,000 Hz. As we grow older, our ears lose their sensitivity to high frequency sounds and by fifty years of age, the average person has completely lost the very highest frequencies. When we reach sixty years, most of us experience considerable hearing loss above 4,000-5,000 Hz and since most insect songs are at frequencies above 4,000 Hz we hear only those few singing in our range. It is no wonder that those of us pushing eighty years are at a definite disadvantage.

There are about 23,000 grasshopper and cricket species worldwide, and each species is said to have its own "song." Most are members of the order Orthoptera that is generally divided into two groups: grasshoppers and relatives that have antennae that are shorter than the body, and crickets and katydids that have antennae as long or longer than their bodies. Cicadas are also common singers, but they are considerably bigger and belong to another order that have piercing sucking mouthparts and wings held roof-like over the body.

The annual cicada sings only during daylight hours and starts the insect chorus from the trees in late afternoon with a rising zing-zing-zing sound that some listeners think sounds like someone sharpening scissors against a grinding stone. The cicada has a pair of special sound producing organs, each of which has a stretched membrane that is controlled by strong muscles. When these contract and then release they cause the membrane to pop, and when done rapidly, create a loud buzzing song that is amplified by a hollow area in the abdomen.

At dusk the male crickets begin rubbing their wings together, dragging a small peg on one wing across a row of ridges on the other. The result is a series of clicks similar to what happens when you rub your thumbnail down the teeth of a comb only so fast that you don't hear the individual clicks but a trill. Black field crickets used to come into the basement in our older house and no one minded their cheerful chirping from the woodpile. The tree crickets produce short, evenly spaced trills and we hear them constantly from any wooded areas.

Later, the last singers of the day take over and sing almost until dawn on warm nights. The katydid is a large green insect that resembles a leaf and can reach 2 1/2 inches in length. It is named for the rhythmic song it produces, to which some hearers have given the words “kay-tee-did” or “kay-tee-did-did”. Katydids produce their songs by rubbing a file-like structure on the bottom of one wing against a sharp edge or scraper on top of the other wing. As the file is drawn across the scraper, thin membranes on the wings vibrate rapidly to create the sounds.

Rather than rubbing their wings together, short-horned grasshoppers (that are sometimes incorrectly called locusts) rub their legs against their wings. Short pegs on the inner surface of the hind-legs are drawn against the stiff outer edges of the hind-wings, and the sounds made in this way are typically very soft and may be difficult to hear. In contrast, one group, the band-winged locusts, make clicking or rattling sounds as they fly, often accompanied by flashing of the wings. These sounds are generated when wing membranes are suddenly popped taut and often occur during courtship flights, although they may also be used when the insect is startled into flight.

Some insect enthusiasts have now adopted an advanced digital device called “The SongFinder” which was developed for bird watchers who suffer from high frequency hearing loss and are unable to hear high-pitched bird songs. Unlike conventional amplifying-type hearing aids, The Songfinder works by lowering the frequency of high-pitched songs into a range where the listener can hear. Furthermore, it is a two-channel "binaural" device that allows the user to determine the direction and distance of the sound source.

This cacophonous mixture of chirps, trills, ticks, scrapes, shuffles, and buzzes -- the songs of grasshoppers, crickets, katydids, and cicadas serenading their females -- will continue for the next month or so until cold weather dampens their enthusiasm and finally a heavy frost will bring the chorus to a close. Winter months are silent and long... and coming.


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August 19, 2008: Bird Watching is Like Fishing?

Did you happen to see the black-bellied whistling duck that reportedly visited an area farm near some of the floodwaters two weeks ago? Perhaps other more pressing business held your attention, but its sighting was a major event for some people. Its presence was announced on a birders’ hotline on the Internet and soon they arrived from far and wide to catch a glimpse of this Mexican duck that seldom ventures so far north. It is a distinctive looking bird with a long neck, long legs, black belly, and white wing patch, and is notable as it perches and even nests in trees.

Birdwatchers are a growing and enthusiastic community. Husband Bill and I attended an Elderhostel program in Minnesota last fall that was centered around this topic and led by three avid birders. Local residents must have rolled their eyes as they rounded a corner on one of the back roads nearby to find three vans stopped almost in the traffic lane with their passengers piling out to view some unidentified bird up in a tree. We calculated that we drove some 600 miles in four days looking for new species.

Although the practice was frowned upon by two of our leaders, the third often produced his iPod that was programmed with birdcalls that played through a small remote speaker. He would use it in two ways -- broadcast the call of a particular bird in the hopes that it would draw one of that species to show itself, or play the call of a screech owl. Any number of small songbirds will not tolerate this little predator in their territories and will gather to attack and drive it away. When the recorder was played, the first to arrive was usually a chickadee, and the bird would search around the speaker for the intruder. It would soon be joined by others until nearby branches and shrubbery were alive with angry birds.

The observation of live birds in their natural habitat has only become a popular pastime in the last hundred years. In the 19th century almost all students of birdlife had to shoot their subjects to get a close look at them – a process that did nothing for the population of the more rare species. Modern bird-watching has been made possible largely by the development of affordable binoculars, as even the least expensive pair can make a big difference in appreciating and identifying one of the tiny creatures.

A case in point was a sighting we made a few years ago in Belize. We were in that country for another Elderhostel and were spending a few days beforehand up in the highlands south of our destination at some Mayan sites. Staying at the same resort was a traveling birding group and they were quite noticeable with their ever-present binoculars and cameras with impressive lens systems attached. Husband Bill and I saw movement in a tree along the main path, and using the tiny inexpensive binoculars we carry on trips for just such occasions, saw that it was a pigmy owl – one of the species the birders were seeking. Within seconds of the discovery, we were surrounded by many thousands of dollars worth of high-tech equipment, and found ourselves to be mini-celebrities that night for having found the elusive bird.

Bird watching is something like fishing when you throw the catch back into the water, or perhaps more like collecting stamps or figurines. The object for many is to find and identify as many species as possible, a process that requires travel to likely habitats, patience in searching once in the area, and either a knowledgeable companion or good identification books to put names to what is found. The rewards are many: hobnobbing with a variety of fascinating people with a common interest, an excuse to visit new and sometimes remote areas, and an incentive to spend lots of time in the outdoors.  Most birders have life lists that they have kept for years, and most also have other specialized lists as well, such as backyard lists or state lists, generally containing date, time and location of the sighting, and even habitat details and weather. Casual enthusiasts such as Bill and I don’t bother with the bookkeeping, but are always on the lookout for a new species and carry binoculars whenever and wherever we hike.

In 2001, the National Survey of Fishing, Hunting and Wildlife-Associated Recreation reported that the state of Wisconsin had 3.1 million people observing wildlife, and that they spent $1.3 billion on equipment and other trip-related costs each year. Of that amount, visitors spent $152 million on food and lodging and $78 million on transportation. Birding was reportedly the most popular wildlife watching activity, and over the past 10 years, the Wisconsin Department of Natural Resources has put together several different nature trails, collectively called the “Great Wisconsin Birding and Nature Trail”. Also each spring, birders celebrate International Migratory Bird Day on May 13 by hosting 19 events for visitors around the state. Even more impressive was the national report last year on outdoor recreation activity that reported that wildlife watchers spent $45 billion of a total of $120 billion spent on all wildlife-related recreation nationwide. Birdwatching is certainly big business but most of us are content to keep our eyes open and ears tuned to the sights and sounds of these feathered creatures and enjoy their presence in our yards and neighborhoods.


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August 12, 2008:  Spiders: Oh, My!


Take a walk shortly after dawn one of these foggy mornings and you will probably be amazed at the numbers of flat webs spread across your lawn made visible by the dew. These are the work of one of our very common spiders called the sheet weaver (obviously from the shape of its web).  You might even want one of the tiny spiders to climb onto your clothes, for if you give credence to the old British superstition you will believe that it has come to spin you new garments, meaning financial good fortune. You also may be interested to learn that the world record for the largest outdoor web was created by many thousands of these spiders at Kineton High School, Warwick, UK, that covered its entire 11-acre athletic field.

Sheet web spiders come in hundreds of species, many of which are so small that they must be examined with a powerful hand lens. My favorite is somewhat larger and grows to about 0.2 inch long – the bowl and doily spider. It weaves a fairly complex structure consisting of an inverted dome-shaped web suspended above a horizontal sheet web (the doily). The spider hangs from the underside of the "bowl", and when small flies, gnats and other small insects land on the webbing, it grabs them.

Spiders belong to a large group of related creatures called arthropods, a term meaning "joint-legged", as all have hard outer-body coverings with bendable leg joints. The tough covering is similar to a skeleton, only it is worn on the outside of the body and acts both to support and protect. As the creature grows, this "exoskeleton" must be shed, making way for the larger version.

Mites, ticks, daddy longlegs, and scorpions are close relatives of spiders and all have 4 pairs of walking legs and hollow fangs adapted for liquid feeding instead of jaws with teeth. Spiders have two unique features, however -- they have spinnerets, which secrete silk during all stages of life, and they use a unique form of mating, in which the male transfers sperm to the female using special appendages near the mouth. In addition, most spiders have eight eyes, although many do not see very well and rely on sensing vibrations with the hairs on their legs. Almost all of the 105 spider families have venom glands, and once prey is caught, the spider injects poison and digestive juices that turn its victim’s insides into a "soup" which is then sucked up.

There are generally two types of spiders, depending on how they capture their prey—hunting spiders and web-builders. All produce silk but only about half the species construct webs to capture food. Spider silk is a remarkably strong material and is able to stretch up to 40% of its length without breaking. It is composed of complex protein molecules that are pulled through silk glands called spinnerets that somehow change it from a stored gel into solid fiber. Depending on the species, spiders will have from two to eight spinnerets, usually in pairs, and each produces a type of thread for a specific purpose such as web construction, defense, capturing prey, or moving about.

Our most visible and beautiful web is probably that of the golden garden spider, an orb weaver that produces a large flat, wheel-like structure. This may reach two feet across and always has a zigzag pattern of silk down the middle. It will contain some 33 yards of silk thread with an average diameter of 0.15 mm, so small that we are able to see the web only because of the reflection of sunlight on the threads.

The orb spider rests on a prominent weed stalk and releases a thread that the wind carries to another nearby stem. It then crosses this “bridge” dragging a loose thread to another anchor to form a “Y”. From this foundation it attaches other radii until it has a wheel with many spokes, upon which it lays a spiral of sticky threads and then hangs head down in the center awaiting prey. If the web is damaged, the spider removes the silk in the morning by eating it, leaving only the first bridge line, and constructs a new web in the evening.

Golden garden spiders mature and mate in the early fall. The female lays several hundred eggs and the hatchlings over-winter in a silk egg sac that she hangs from a plant stem. Other insects also use the sacs to protect their eggs and in one study, nineteen species of insects and eleven species of spiders emerged from collected cases. The cases partially protect the spiderlings but the vast majority are opened and emptied by birds. In spring, the survivors emerge and disperse.

Not all the spiders in our yard make webs. The wolf spider either pounces upon prey, even chasing it over short distances, or lies in wait for a victim. It carries its eggs in a round egg sac attached to the end of its abdomen. The jumping spider has an internal hydraulic system that extends its limbs by increasing the pressure of body fluid within them. This enables the spider to jump 20 to 60 times the length of its body. Spiders are the stuff of horror films but they are the first line of defense against the insect hordes that threaten to engulf us.


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August 5, 2008:  Robins and More


Probably no bird in this country is more widely known than the robin. It has adapted itself to living near people -- claiming our lawns as its hunting ground, building its nest in our trees, and singing its cheerful song to us at dawn throughout the summer months. Connecticut, Michigan, and Wisconsin have designated it as their state bird but it can be found all across and up and down North America.

Each spring the male robin hurries back from his winter vacation to stake out his territory. He typically went no further south in the autumn than was necessary, and a few didn’t bother leave at all, having chosen to hole up in sheltered spots and survive on dried berries and whatever they could find. Competition for prime spots is strong as the female seems to choose her mate by the quality of his territory, and the sooner he can obtain control over a good nesting spot the more likely a comely female will appear. When she does, the male will begin to sing and display, expanding his tail feathers and lifting them until they fan above his head. If the female seems interested, he will pursue her with a quiet hissing sound until she accepts or rejects him in which case he will try again with another female. Once a robin pair mate, the male will chase off any other intruding males.

A good nesting site is usually about ten feet above the ground on a forked tree branch, although we have had birds build on the steps to the loft in the barn, on rafters in the shed, and all sorts of other sites. The nest itself is in the shape of an open cup and is constructed of a foundation of dry coarse materials like grasses, twigs, and twine with a mud layer compressed against it. The inner lining is created from soft grasses and strings and she will use her body to press the materials firmly in place, going round and round until she is satisfied that all is perfect.  

After laying a glossy greenish-blue egg each day for three or four days, the female will begin to incubate them, rarely leaving the nest and relying on her mate to bring her food. When she does take a break, a cowbird sometimes tries to lay its egg in a her nest, but robins are unusually adept at detecting any intruding egg and usually either poke holes in it with their beaks or push it out of the nest.  Once the chicks hatch, they only remain in the nest for about two weeks and are soon flying about after their parents. The female often re-nests, at which time the male takes over the responsibility for the care and training of the older offspring. When a female robin is not busy with incubating eggs or caring for young, she reportedly builds as many new nests as she can. Usually, most are never completed, but she seems to have an overwhelming urge to work at them.

Robins are thrushes, a large family of birds that are mostly found in Europe and Asia. Most New World thrushes are brown and have speckled breasts, and it is interesting that the two species in our country that don’t – the robin and bluebird – have spotted breasts as juveniles.

Thrushes are well known for their beautiful songs and my favorite is the wood thrush, perhaps because it is associated with the deep woods and has an almost ethereal sound. The first low-pitched notes are almost inaudible and followed by a louder phrase that is often written ee-oh-lay. The third part is a trill-like phrase made up of pairs of notes, as the bird is able to sing two notes at once. Each individual bird has its own repertoire based on combinations of variations of the three parts.

The wood thrush has a cinnamon-brown head and back and a white breast and belly with large dark brown spots. It, along with many of the other thrushes, is considered a neotropical songbird – a term that refers to those species that spend about eight months of the year wintering in Central and South America and the remaining months on their breeding grounds in North America.  The wood thrush has become a symbol of the decline of these birds of eastern North America, having dropped 43 percent since 1966. The breaking up of North American forests giving predators and cowbirds access to wood thrush nests, and the continued destruction of forest in Central America where they winter, are thought to be major causes. Despite this drop, the wood thrush has not been listed as a threatened species – and there are still many to grace our woodlands.

We have never seen a veery in our upland woods, but it was very much in evidence at our cabin in the low wet woods in Columbia County. It is relatively unmarked among the thrushes, as its speckles are faint, and it has pale or non-existent eye rings, but its song is distinctive with several quick phrases that drop in pitch. The Swainson’s, gray-cheeked, and hermit thrushes pass through our area during migration, but only the hermit is easily identified as it works noisily through the dry leaves on the forest floor looking for bugs. Its rufous tail is a give-away. Of all the thrushes, it and the bluebird are the only ones whose population seems to be increasing across the continent. Bluebirds deserve their own story so I will write about them another day, but all the thrushes are very special and well worth getting to know.

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July 22, 2008: Moles or Corn?


Well, it has finally happened. Against all odds, I have decided that I have been disseminating incorrect information – in other more succinct words – I goofed! Each succeeding gardening season I have been having fewer corn seeds sprout in my vegetable garden. We even went to the extreme of planting some seed wrapped in bits of steel wool and copper scrub pads and slipped between the strands of heavy plastic cord. The cord was left, as well as strands of copper, but the seeds and even the steel wool disappeared! It has been very obvious that moles were involved, as their tunnels appeared within days of planting and ran right down the rows, but I, having read the statements of many “experts”, was convinced that mice in the tunnels ate the seeds. Source after source asserted that moles were carnivorous, dining only on earthworms, grubs and other ground-dwelling creatures. Read these:

 “It has long been known to scientists, through careful study and investigation, that the diet of moles consists mainly of the insects, grubs and worms to be found in the soil… While plant fibers or rootlets show up… in no case was the amount of identifiable plant tissue more than might have been taken in incidental to the ingestion of other food” (i.e. animal tissue). from a farm bulletin from Kansas State Agricultural College.

 “Moles are often accused of damage to bulbs and garden crops -- damage which is really done by mice that invade their burrows.” Nature Bulletin No. 514-A Forest Preserve District of Cook County (Illinois)

“Moles are almost entirely carnivorous; however, it is true that moles can indirectly kill plants. They do this in two ways: The tunnels created by moles will often be used by other small animals… The mole will scrape the dirt away from the roots in search of food.” Mole-Pro, seller of mole traps.

Since I always believe anything I read on the Internet, I accepted these pronouncements as gospel, despite the evidence in my own garden. Now, with more diligent research, I find there are others who know better. In Habits of the Common Mole, F. A. Hanawalt  of the Department of Biology, Otterbein University reported that “Moles are often said to be entirely insectivorous. It was shown, to the author's satisfaction at least, that moles are guilty in some cases of eating sprouted corn and in rare instances of eating roots and tubers. Moles in captivity will eat soaked corn readily… “. I have now discovered other similar sites and I now am faced with the choice between eating homegrown sweet corn or plotting the extermination of the marauders.

Few people have ever seen a mole. That is because this strange animal lives its entire life underground. It has a six-inch, torpedo-shaped body covered with velvet-like fur that has no nap, so that it can easily move through its underground tunnels either forward or backward. It has a cone-shaped head with a long sensitive snout used for feeling out earthworms, grubs and other food (like corn seeds!), and a short naked tail that guides it when moving backwards along the runways.

One of our species, the star-nosed mole, gets its name from an odd-looking ring of fleshy appendages that fan out around its nose. These are covered with thousands of unique sensory receptors called Elmer's organs that presumably assist the animal in finding food. By contrast, the Elmer’s organs of the common mole lie below a thick layer of skin and do not seem to be of much use. All moles rely heavily on their senses of smell and touch, as their extremely tiny eyes are little more than thin membranes that allow them only to sense light and little else.

A mole literally "swims" through the soil in its search for food. Its shoulders and forelegs are tremendously powerful with broad, shovel-like paws, each armed with five heavy claws, and these are brought forward alongside the snout, then thrust outward and backward in a breast stroke, pushing the soil aside and pulling the animal forward. The soil above arches and cracks leaving a humped and broken trail and excess earth is pushed into heaps above the surface.

An adult mole lives a solitary life and avoids contact with other moles except during the spring mating season when a male will range some distance in search of females. The female mole ordinarily has one litter of four young in a deep nest chamber in April or May. The naked and helpless young grow quickly and, at the age of three months they are nearly as large as their parents. In autumn all move into deeper tunnels below the frost line and remain active all the winter.

A mole has an enormous appetite and has been reported to eat the equivalent of its own weight each day. Away from our lawns and gardens it is considered to be an extremely beneficial animal, but right now it is definitely on my list as an undesirable. I will probably resort to coating the seeds with something next year, but as the reports on this control are not encouraging, I may have to invest in some traps. Oh, dear…


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July 15, 2008: Which is Which?

All of us can probably remember being taught in science class that some insects receive protection because they strongly resemble another species that stings or is toxic. One example often given was that of two butterflies – the monarch and the viceroy – both of which have orange and black wings. The only noticeable difference between the adult insects is in the pattern of black veins on their lower wings, as the monarch has a jagged vein across the lower wing while the viceroy has a continuous line.

The two species are actually very different. The caterpillar of the viceroy is greenish brown with a whitish saddle, and has horns with short thick branches on four of its segments. It feeds on the leaves of willow, poplar, and cottonwood trees, and over-winters as a chrysalis. The monarch caterpillar is white with yellow and black stripes around its body and two black fleshy filaments on each end. It feeds exclusively on milkweed leaves and transforms into a roundish light green chrysalis decorated with gold spots. In the fall, these butterflies migrate to Mexico, traveling several thousand miles. 

The theory has always been that since many predators tend to avoid the monarch after one taste, because of chemicals it stores in its body from its milkweed feedings, they also avoid the viceroy because of its similar looks. Now new research has discovered that the viceroy is actually more unpalatable than the monarch and that each may receive protection from the other.

The willow family, upon which the viceroy caterpillar feeds, produces salicylic acid in its bark and leaves. Willow bark extract became recognized for its medicinal effects on fever, pain and inflammation in the mid-eighteenth century and later became the primary ingredient in aspirin, but excessive use can cause uncomfortable side effects. The viceroy caterpillars store up the salicylic acid in their bodies and it makes them bitter and unpalatable. It also causes digestive irritation, bleeding, diarrhea, and even death when consumed in high doses.

Most people are familiar with milkweed. As children we were fascinated with the white sap in its stems and leaves, as well as the pods full of seeds that were equipped with parachutes. Milkweed pods were even gathered during World War II and the floss was extracted and used as fill for life jackets. The milky juice contains alkaloids and several other complex compounds, and also a latex that was researched extensively as a natural source for rubber by both Germany and the United States during that war. (The major commercial source of natural rubber latex has always been a tropical tree, largely because it can produce a continual supply of latex if wounded. Other plants containing this substance include figs, lettuce, euphorbias, and even the common dandelion.) This caustic sap presumably protects the plant from being eaten, although the monarch caterpillar and the larvae of a variety of other beetles, moths, and true bugs do feed on the plants because they are not sensitive to its chemicals.

Mimicry has long been a topic of interest to the scientific community. Many insects, as well as other organisms, resemble other species for the obvious reason that they are closely related, but there are numerous instances where very different species have evolved to look alike. Sometimes only one of the involved species receives a benefit from this situation such as the clearwing moths that resemble wasps. The moths presumably receive protection by looking like dangerous predators, while the wasps aren’t affected one way or another. Often the mimicked insect has advertised its danger with bright warning colors and the similar coloring protects the mimic, despite its harmless nature.

Fritz Muller was a German zoologist who described a different type of mimicry in 1878 when he discovered that in a number of instances several unpalatable species share a similar warning pattern. He suggested that a predator who has had a bad experience with any one of these would avoid all of them, thus benefiting everyone. Such a situation is now called Müllerian mimicry after him and it describes the group into which the monarch/viceroy relationship has been placed. Incidentally, the viceroy exhibits additional mimicry in both its larval and pupal stages as their form and color strongly resemble bird droppings, although I’m not sure any bird would be fooled. This would put it into the former type of mimicry for those portions of its life.

Monarch butterflies are usually much more commonly seen than the viceroy and many people do not even realize that they are two different species. Still, they can be readily distinguished even at a distance as the viceroy flits around energetically, while the monarch lazily floats here and there. This season, at least here at the farm, we have seen many viceroys and almost no monarchs; last year it was the other way around, and I hope the monarchs will still make a showing before the summer is over. We grow milkweed specifically for them in the garden and enjoy watching the caterpillars grow up, change into their jewel-like chrysalises, and then emerge as adults before moving on. I have never found a viceroy caterpillar, but I understand that their eggs are laid high in the treetops so that the larvae would be far out of sight if growing in our big willow. If both the caterpillars and chrysalises look like bird droppings, I’m not sure I would recognize them if I saw them anyway.  


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July 8, 2008: Red Heads and More


Red-headed woodpeckers have been very much in evidence around the farm and neighborhood this year, after years with very few sightings. The Breeding Bird Survey has indicated that the species is declining over much of its breeding range, and the reason given is usually loss of suitable habitat and the invasion of European starlings that take over available nesting holes. Why that should affect the red-headed more than other woodpecker species that seem to be managing pretty well is hard to understand, so it may be that other undiscovered factors are in play.  Whatever has been happening, their numbers have rebounded in our area, as I have seen dozens of these striking birds in past weeks.

The red-headed is a medium-sized woodpecker distinguished by its bright red hood, white chest, and black wings with large white panels that show up prominently both at rest and in flight. All woodpeckers have red on their heads, presumably to grab the attention of the opposite sex when they drum in courtship, but only the red-headed have completely red heads. I should point out, however, that juvenile heads are grey and don’t get their color until they are old enough to breed.

This is one of the most aggressive members of the family and has the most varied diet. It will eat seeds of beech and oak, nuts, berries, fruit, insects, bird eggs, nestlings, and even mice (presumably dumb ones). In addition to attacking other birds to keep them out of its territory, the red-headed is also known to remove the eggs of other species from nests and nest boxes, destroy nests, and even to enter duck-nesting boxes and puncture the duck eggs.

The red-headed is one of only four woodpeckers known to store food, and often covers its hoard with wood chips or bark. It hides insects and seeds in cracks in branches and under loose bark, and has even been seen to stash prey under roof shingles. Grasshoppers are regularly stored alive, but wedged into crevices so tightly that they cannot escape. The red-heads are less likely to drill for food than other woodpeckers; instead, they fly down to the ground to capture insects or snatch them from the air.

The male establishes the territory and defends it by drumming and calling a loud "tchur-tchur." He chooses a natural cavity nest site if possible or excavates a new one if necessary, and fends off competitors with aggressive displays by spreading his wings, fanning his tail while bowing and bobbing. When a female appears, he will stretch his neck and hump his shoulders with his feathers sleeked back, and if she is receptive, she will tap on the outside of the nest while he taps on the inside. Four or five white eggs are laid in May with incubation and care provided by both parents. There is usually only one brood a year in the northern part of their range, although they will often re-nest if the first brood is not successful.

A woodpecker has several characteristics that set it apart from other birds. Its feet are adapted to clinging to a tree trunk with two toes pointing up and the other two point down, in contrast to those of other birds that have three toes pointing up and just one back. It has reinforced tail feathers that allow it to lean back from a vertical surface and chisel with its beak. Its brain in tightly enclosed in its skull and padded with cartilage so that repeated pounding on hard wood does not damage it. Its strong, pointed beak acts as both a chisel and a crowbar to remove bark and find hiding insects. But perhaps its most unique feature is its tongue.

In order to reach prey inside wood, a woodpecker's tongue must be longer than its bill. In the red-bellied woodpecker the tongue extends about three times the bill length but in other species the tongue is so long it forks in the throat, goes below the base of the jaw, and wraps behind and over the top of the head, where the forks rejoin and insert in the bird's right nostril or around the eye socket. Within the entire length of woodpecker's tongue lies a series of tiny bones sheathed in muscles and soft tissue. These fold up accordion-like along part of their length and when the woodpecker wants to stick out its tongue, it contracts muscles near the base, forcing the bones forward and out of the bill. Relaxing the muscles allows the tongue to shorten and brings it back inside. The tongue also contains paired lengthwise muscles that move it side to side.

While feeding, a woodpecker listens for sounds of grubs chewing inside a tree and then drills out a hole just wide enough to insert its beak. Wood-boring beetle larvae often form extensive tunnels and when the woodpecker's bill breaches one of these tunnels, the bird extends its tongue and probes around. If it locates a grub, its sharply barbed tongue skewers the soft body and then withdraws the impaled grub.

Watch for one of these fascinating and strikingly beautiful birds perched on a branch or utility pole or darting after a flying insect. We hope this comeback will prove permanent. 

July 1, 2008: About Lightning Bugs

 
Mother nature has done it again – put together another seemingly impossible scenario that our scientists with all their expertise and ingenious paraphernalia have not been able to duplicate – and it has to do with a little bug that almost all of us as children collected on a summer’s evening. A firefly is about ½ inch long, cigar-shaped, and flies about in our yards, but what makes it exceptional is the light it gives off, as even its eggs and larvae glow. There are about 136 different species around the world and they are common in the eastern half of this country as well as in warm, humid areas around the world.

Usually at dusk, the male firefly emerges from hiding and flies about, emitting one or a series of short flashes depending upon his species, at regular intervals. The female waits on a low perch, and when a male approaches, will give off an answering flash. Exchanges of signals are repeated several times until the pair find each other, and then with luck the male will escape, as given the chance female will devour him.  After mating, the female will deposit her eggs in damp soil, and in about three weeks young sowbug-like larvae will hatch with tiny spots on their undersides that glow softly. All firefly larvae produce light, possibly as a defensive measure, as it has been shown in the laboratory that predators avoid such glowing objects after experiencing their taste. The larvae are voracious predators that eat earthworms, snails, slugs, and mites, injecting strong digestive juices into their prey before sucking out the insides and leaving an empty skin. Most firefly larvae live one to two years and are found in rotting wood or other forest litter. In late spring they change into pupae, and in about 10 days, emerge as new adult beetles that will live as long as it takes to mate and produce eggs, often only a few days.

The last few segments of an adult firefly’s abdomen are made up of thousands of specialized cells that contain luceriferin and luciferase, rare chemicals that generate light in the presence of oxygen, as well as an enzyme that provides energy for the process. The light emitted by fireflies is unique in that nearly 100 percent of the energy is given off as light. This is in contrast to tungsten electric lights where only 10 percent of the energy emitted is light and the other 90 percent is given off as heat. Although a few other insects can produce light, fireflies are the only ones that can flash their lights at will and it has only been very recently that scientists have discovered how it is accomplished.

Neurobiologists at Tufts University were puzzled because they could find no nerve link to the light-producing cells in the firefly’s tail, although they did find that they could cause the cells to glow if they exposed them to molecules of nitric oxide gas in the presence of oxygen. Furthermore, they observed that the cells had a thick outer layer of mitochondria, a substance that reacts with oxygen to create energy for the cell and guessed that these mitochondria could block any light-creating chemical reaction. They also discovered that a signal from the insect’s nervous system activated an enzyme that produced nitric acid that deactivated the mitochondria. As the nitric acid signal decayed, the mitochondria resumed their oxygen consumption that turned the light off -- all of this occurring in a fraction of a second. The fact that nitric acid passes through cell membranes, degrades within seconds and must be made fresh for each use makes it an important transmitter and signaling molecule.

The really fascinating part of this story is that scientists have found that luciferin and luciferase are extremely useful as markers in research on such problems as cancer, multiple sclerosis, cystic fibrosis and heart disease. As all living cells already contain the energy-providing enzyme, injection of the firefly's chemicals cause flashes of light that can be measured and used to detect energy problems in human cells. Now, electronic detectors using firefly chemicals are also used to signal that milk, food or water may be contaminated with bacteria, and detectors have even been placed in spacecrafts to look for earth-life forms in outer space. I read that if as little as one quadrillionth of a gram of the enzyme enters the rocket's detector, a flash of cold light will be given off and recorded by earth-bound scientists.

Although most of the luminescent species are insects, the capability is also present in some bacteria, fungi, algae, one-celled animals, segmented worms, arthropods and fishes. Some, like the fireflies, use their light in courtship, while others use the flashes to frighten off enemies or attract prey. The colors produced vary, as well, as some are red, others blue-green or yellow. The problem is that not only are luciferin and luciferase quite rare but they have so far proved impossible to synthesize. This has made the propagation of fireflies a high priority activity in some circles and the Sigma Chemical Co. of St. Louis, Missouri purchases and provides fireflies throughout the world for conducting research in a wide variety of scientific areas. I am told that they will pay a penny for each bug if you will send them at least 25,000.


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June 24, 2008:  Miracle Moth


It seems there is something almost miraculous about the appearance of the exquisite silk moths that hatched from my cocoons this past week. Last year I tended dozens of caterpillars for several months and ended up with cocoons from four species: the big beautiful cecropia with its 6-inch wingspan, the much smaller promethea, and the less-often-seen luna and polyphemus. All are present here on the farm naturally, but we seldom see them because they live only a few days as adults and most fly only at night.

Even though I lived in an urban area as a child, there were plenty of hedges, shrubs and trees in our yard and throughout the town, and we had a variety of butterflies and moths. Each winter I almost always found at least one cocoon and often had several that I carried home. I carefully stored them on our screened back porch, after learning early that keeping them indoors in the warmth would cause the moths to emerge far too early for a safe release. I always marveled at the beauty of the insects that emerged in the spring, but it was not until a few years ago that I collected eggs from mated females and raised the caterpillars as well.

Butterflies and moths have four wings, two forewings and two hind wings that are powered by strong muscles that move the wings up and down in a figure-eight pattern. The wings are composed of two layered membranes that are supported by tubular veins, and when the adult insect emerges from its pupa, they are crinkled and wet. It then hangs upside-down and pumps fluid into the veins in the wings to inflate and expand them and must wait for the wings to dry before it can fly. Covering the wings are thousands of colorful scales made of tiny overlapping pieces of chitin, together with many hairs.

Although quite similar, butterflies and moths have a number of differences: butterflies fly by day while most moths fly after dusk; butterflies have slender hairless bodies but most moths have fat furry bodies; butterflies have hair-like antennae that end in knobs but moth antennae lack the knobs and often branch like feathers; butterflies typically hold their wings up vertically when at rest while most moths hold their wings out flat; the pupae or resting stages of butterflies (called chrysalises) are naked and exposed while those of moths are usually formed inside woven cocoons or hidden under the soil. They both belong to the same insect order, however, that is divided into some 180,000 species.

The giant silk moths are the largest moths in the United States and Canada and emerge from their cocoons in June. They live only long enough to mate and lay eggs and then die, as they have only rudimentary mouthparts and eat nothing during their short adult lives. In about two weeks, tiny caterpillars that seem to be mostly mouths eat their way out of the eggs and then begin to feed on the leaves beneath their feet. Each species has only a few host plants that they can use and the mother moth has carefully sought them out using sensors on her antennae and feet to detect chemicals that are given off by them. My various caterpillars fed happily on the leaves of birch, wild cherry and apple trees.

The caterpillars are little more than eating machines that spend the next four to six weeks filling their expandable bodies with food, splitting their skins when these become too tight and then growing some more. Most become food for birds and other hungry creatures, but those that survive go through an amazing transformation. First they use a pair of specially modified salivary glands in their mouths to produce an endless strand of silk that they weave into a tough shroud. Inside the completed cocoon, each splits its skin a final time revealing a legless, wingless object with only the impressions of its future self embossed onto its skin. Most spend the winter in this form, but inside the pupa a cluster of dormant cells begins to grow and divide, feeding upon the old caterpillar cells until the insect takes its new form.

When a female moth emerges from its cocoon, it hangs quietly in place until late in the evening. Then it extends a gland from the tip of its abdomen and emits a chemical pheromone whose molecules float off on the air currents. Male moths use their feathery antennae to detect the chemicals and have been known to travel many miles to a female. As soon as one finds her, he presses his tail to hers, effectively shutting off the source and the other suitors disappear almost immediately to look elsewhere.

I was not able to collect eggs from the luna and polyphemus moths that hatched from my cocoons, but I do have some extra eggs of the cecropias and probably will have some of promethea, as well. If any of you are interested in trying to raise a few, give me a call. You will need a good supply of leaves (I use apple for the cecropia) as they grow to be very large caterpillars and are hearty eaters. I fed some in a homemade cage and put the others in a mesh sleeve that was pulled over an apple branch – a system that is far less bother and that works very well if you have a convenient tree. Either way, you will be able to observe this process from start to finish, and next spring with care and a little luck you will have your own spectacular show as the moths appear.


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June 17, 2008: Frogs, Toads, and Salamanders


It sounded as if some disgruntled musician was twanging on a loose guitar string, and I knew that the green frogs were adding their voices to the amphibian chorus at the pond. The rains have been the sole topic of conversation around the area this past week, with sad tales of inundated crops, flooded homes, difficulties with travel, wet basements, and even drowned animals. Still, there are creatures that have actually enjoyed this awful weather – namely our frogs, toads, and salamanders.

The term amphibian means "both life forms" and refers to animals whose development almost always requires that they live part of their lives in water and part on land. Wisconsin boasts twenty-one native amphibian species -- eleven frogs, one toad, and seven salamanders. Some breed in temporary ponds that are formed by melting snow or rain, some only inhabit lakes and permanent wetlands, while others use woodland pools.

Amphibian eggs have yolks that are grayish yellow and are usually surrounded by a greenish gelatinous material. Some are attached singly or in masses to aquatic plants, others are in long strings, and still others float on the surface of the water. Those that are exposed to direct sunlight often develop dark pigment on the exposed side, a characteristic that is thought to protect the developing embryo from ultraviolet radiation and to absorb heat.

Frog and toad tadpoles feed on algae and other minute plant matter and as they become mature, they undergo remarkable changes. First, they grow back legs, then front legs, and then slowly reabsorb their tails. At this point, the tadpole stops eating and the tail tissue provides nourishment as its digestive system switches from utilizing plant material to living prey and its respiratory system changes from breathing with gills to lungs. Most tadpoles mature and change into adults within weeks, while others may take several years.

Salamanders are much less likely to be seen than frogs and toads, but it is because of their retiring habits rather than their numbers. Research in New England has shown that the mass of salamanders exceeds the bird and mammal life in some forests. Salamanders are sometimes confused with lizards, but reptiles have scales on their bodies and claws on their toes and salamanders have smooth or warty moist skins and are clawless. Most cannot travel very far from water where they lay many jelly-like eggs that hatch into gilled larvae that look similar to small fish. Juvenile salamanders, unlike tadpoles, have bushy gills and projections near their necks that help them stay upright in murky water.

As the salamander larvae mature, they absorb their gills and develop lungs and feet. Mudpuppies are an exception and never loose their larval looks. Another unusual species, the central newt, has a unique development that depends on its surroundings. If a pond dries up, the newt loses its tail fins, changes color from green to brown, and lives in the woods as an “eft”. If the pond later fills up, the eft will go back to the water, although it won't develop gills. These newts can oscillate between these life styles as conditions require.

Female amphibians often lay enormous numbers of eggs. In general, larger species have more eggs than smaller ones, and salamanders lay fewer eggs than do frogs. Giant bullfrogs can produce up to 20,000 eggs, while the tiny gray treefrogs will lay as few as 10. Blue-spotted salamanders produce about 40 eggs, but spotted salamanders will lay as many as 250. Most amphibians emigrate from the breeding ponds after mating, leaving the eggs unprotected.

In the 1970s, concerns were expressed about declining leopard and cricket frog populations in Wisconsin, and in 1989, a symposium was held in England where scientists from 63 countries shared their research on apparent worldwide declines in amphibian populations. They could not agree on one single factor to explain population drops but suspected a range of causes including widespread destruction of habitat, changing land uses, plus a number of others. Part of the difficulty is that estimating amphibian populations is a tricky business. Here in Wisconsin, for example, although some species are on the decline, spring peeper populations seem stable, and wood frog populations are even increasing. Leopard frog populations took a big dip in the 1970s, but now appear relatively stable. Since 1981, the Wisconsin Department of Natural Resources has coordinated a three-times-a-year statewide frog and toad survey, sending 100 volunteers throughout the state to visit wetland sites where they listen for and catalog calling frogs and toads.

Amphibians are the top predators in many wetlands and along waterways, consuming a wide variety of insects and other invertebrates. On the other hand, amphibians are also a favored food for a variety of fishes, reptiles, birds, mammals and other amphibians. As such, they are important links in the food chain and we would do well to be sure conditions remain satisfactory for their survival.

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June 10, 2008: Everyone Loves a Baby

I almost stepped on the little guy flattened in the grass. He lay absolutely frozen in place and only a slight movement of the hair on his flanks proved that he was alive. The baby woodchuck could not have been more than five or six weeks old and had no business being out by himself, and I’m sure he was regretting his daring. Mother and the rest of the family were watching to see what would happen from the safety of the den under Jim’s solar kiln, and she chirped her warnings for him to stay put. I posed no danger but certainly there were plenty of others around that would have relished such an easy meal.

This common rodent, that is actually a member of the squirrel family, will grow to more than two feet in length and weigh up to 14 pounds if he lives long enough. The woodchuck is almost a complete vegetarian, eating leaves, flowers and soft stems of various grasses, field crops, and herbs. It is very fond of garden crops like peas, beans and corn and will even climb trees for apples and other fruit, and I was glad that the den was some distance from my sprouting vegetables.

Woodchucks have burrowed under the cement floors of the kilns to make their dens ever since the kilns were installed, but more typically live along the edges of wooded areas that are bordered by open land. Several tunnels lead to an enlarged nest chamber, 3-6 feet underground, and the main entrance is usually conspicuous because of the pile of dirt and stones. In digging, the animal uses its strong front feet and claws primarily, but it also moves stones or cuts roots with its big teeth. The amount of subsoil removed in the course of digging one burrow averages an almost unbelievable 716 pounds.

In Wisconsin, woodchucks usually hibernate all winter, emerging around the first week of April if the weather allows. The breeding season soon begins and a litter of two to nine naked, blind and helpless cubs are born in early May. Their eyes open at about 4 weeks but they seldom venture outside until 6 or 7 weeks old. The woodchuck occupies an important niche in the wildlife community because skunks, foxes, weasels, opossums and rabbits all use its burrows for their dens and the countless generations of woodchucks have contributed much to the aeration and mixing of the soil because of the tremendous quantities of subsoil moved.

Most of the baby animals in our woods and fields have similar stories. The parents – those that are active throughout the winter like the coyote and fox, those that hibernate like the woodchuck and chipmunk, and those who just wait out the severe weather in their dens like the raccoon and skunk – breed as the winter storms wane and the temperatures moderate. With the exception of squirrel kits that are usually born high in trees, most of the young are cared for in dens underground. Gestation is only a couple of weeks long and so the new babies are mostly naked, blind and deaf, and are only able to pull themselves to a nipple and nurse, and then often need their mother’s help.

They grow quickly, however, and in a month or so, they are venturing to the mouth of the den and peering outside. During their first weeks, all are fed on mother’s milk but the predator-types are quickly introduced to regurgitated meat that the father brings back to the den, and vegetarian mothers soon lead their young out to feed on nearby plants. Soon the dens are abandoned, but the adolescents remain with their parents for their education and protection – sometimes until the next breeding season.

An exception to this scenario is the white-tailed deer as it mates in the fall and gives birth to one, two, or occasionally three fawns that are fully furred and are up on their feet within minutes of their birth. The small white spots on a reddish brown coat help camouflage the young fawn as it lies motionless in the grass or leaves, but it can jump up and run almost immediately to escape a predator. The spots disappear when the fawn gets its winter coat, at about five months of age.

As they leave the dens, all of the various babies are cute furry bundles with bright eyes and endearing faces. Few survive to adulthood, however, and most become just a meal for some larger animal. Even a quick look at the statistics indicates the logic in such a system, however unpleasant. When predators are absent for some reason, populations soar and the balance of nature quickly is lost to the detriment of all. Each parent must only replace itself during its lifetime to maintain the species, but any excess is vital to countless other species. Still, we enjoy each baby we discover and believe it will be the one to survive to share the bounties of our farm.

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June 3, 2008: Mosquitoes: Oh My!


According to Phil Pellitteri, University of Wisconsin extension entomologist, there are more than 10,000 different insects, spiders, and related creatures that you could encounter during a summer walk in Wisconsin. Most are completely harmless, but the less than one percent that sometimes attack people certainly get one’s attention. Black flies, ticks, mosquitoes, chiggers, deer flies and horse flies all require the protein in animal or human blood to make eggs, and some other creatures bite or sting when disturbed or threatened.

Mosquitoes have been around for 100 million years and have diversified into 3,000 species that are very different from one another. They have successfully adapted to climates from the arctic to the equator and developed means of locating a blood supply in each locale. People are never the primary prey especially in temperate climates, and the insects prefer utilizing animals that are most abundant in their habitat such as frogs, birds, or other animals, but they will aggressively attack humans if they appear. Mosquitoes can sense increases in carbon dioxide given off in mammal breath up to 100 feet away, as well as certain chemicals in sweat. As they follow the scent, they see only general shapes and sizes with their compound eyes, but within 10 feet or so, extremely sensitive thermal receptors on the tips of their antennae tell them that hot blood is on tap. The range of these receptors increases threefold when the humidity is high.

There are more than 50 mosquito species living in the state, and Pellitteri contends that the most bothersome come from the genus Aedes. These are sometimes called "floodwater" mosquitoes because if a pond or riverbank dries up, any eggs there can remain dormant for months or years until they are again flooded. Once the rains begin, the pests can appear in less than two weeks, and as many as 100 mosquitoes can emerge per square foot of water surface each day. Female mosquitoes will live for three to six weeks and can take multiple blood meals during this time, laying a new batch of eggs each time, and many are known to migrate 10 to 20 miles from their breeding site in search of a victim.

Like many other insects, the mosquito goes through four distinct stages of its life cycle -- egg, larva, pupa, and adult. Eggs are laid either on damp soil, as is often the case of Aedes, or on the surface of quiet water where they float singly or stick together in rafts of a hundred or more. The length of the egg, larval and pupal stages depend on the temperature and species characteristics. Some will go through their entire life cycle in as little as four days while others may take as long as a month. 


The mosquito eggs hatch into larvae or wigglers, which spend most of their time at the surface of the water breathing through an air tube or siphon, but can swim and dive down from the surface when disturbed. They filter organic material through their mouthparts for food and grow to about ½ inch long, shedding their skin several times. On the fourth molt the larva transforms into a pupa which will
 remain in the water another 1 to 4 days, floating at the surface and taking oxygen through two breathing tubes. If it is disturbed it will dive in a jerking, tumbling motion and then float back to the surface. When development is complete, the pupal skin splits and the adult emerges, resting on the surface of the water to allow its wings to dry and harden. All stages are important food sources for fish and other creatures.

While the Aedes may cause considerable grief through their prodigious numbers, other species are present, as well. The Northern house mosquito, Culex pipiens, is usually the most common pest in urban and suburban settings and is often an indicator of stagnant water sitting around in tin cans, discarded tires and other containers. Culex pipiens is recognized as the primary carrier of St. Louis encephalitis, a virus found in a variety of wild birds including the house sparrow, and the female can pass the virus from one bird to another or to a human as well. Until the appearance of the West Nile Virus, this was the only mosquito-borne disease seen regularly in Wisconsin and it can cause complications in small children.

Worldwide, mosquito-borne diseases such as malaria, yellow fever, dengue fever, and encephalitis kill more people than any other single factor. Mosquitoes also transmit heartworms to cats and dogs. West Nile virus, which has been widespread in Africa, southern Europe, the Middle East and western Asia, first appeared in the United States in 1999 and was found in Wisconsin birds in 2001 and in humans here in 2002. The danger is not very great as very few mosquitoes actually carry the virus and the illness generally has mild flu-like symptoms, but in rare cases, the virus can cross the blood-brain barrier and produce encephalitis, a swelling of the brain and spinal cord that can be fatal.

Mosquitoes and other flies are a vital link in the food chain for many creatures, but few of us have any other good words for them. Fortunately, several excellent chemical repellents have been developed that block their thermal receptors, allowing us to enjoy the outdoors without too much discomfort.

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May 27, 2008: An Insect-bird Cross


Those of you who are up and about at the crack of dawn may be surprised to see that the hummingbirds have risen even earlier and are stoking up at the feeders. These consistently cold mornings with temperatures hovering close to the freezing point must be very taxing for their tiny furnaces, and I would guess that having sugar-water readily available is making a big difference to their wellbeing.
 
Hummingbirds have the highest metabolism rate of any animal on earth -- a high breathing rate, a high heart rate, and a high body temperature -- and to maintain all of this and to provide energy for flying they must consume up to 3 times their body weight in food each day. Much of their natural diet is sugar that they get from flower nectar and tree sap, but they also eat insects and pollen for protein. A hummingbird’s bill is long and tapered to reach deep into flowers, and its tongue is grooved on the sides to collect nectar that it laps up at the rate of 13 licks per second. A hummingbird will feed five to eight times every hour, and in order to gather enough nectar without human help, it must visit hundreds of flowers every day. Just one day of very cold temperatures or bad luck finding flowers can prove fatal.

A hummer does have an interesting way to conserve energy when it can't feed, such as at night or when the weather is too cold or too rainy to fly. It enters a sleep-like state known as torpor in which its body temperature can drop almost 50 degrees F, the heart rate may slow from 500 beats per minute to fewer than 50, and breathing may briefly stop. When conditions improve the bird rapidly vibrates its wings to generate body heat and warm its blood supply, and soon its body temperature rises to its normal 102.2 degrees.

Hummingbirds are native only to the Western Hemisphere, and you can imagine the surprise and even disbelief of the first European explorers when they first saw one. Early writings indicate that they thought these fascinating creatures were a cross between an insect and a bird, and marveled at their size, their buzzing flights, and their bright colors that suddenly changed from dazzling to dark and back again. By the middle of the nineteenth century there was a large market for hummingbird skins in Europe.  Hundreds of thousands of hummingbirds were killed in South America and shipped to markets in London and other cities, where skins were purchased for collections as well as to make artificial flowers, "dust catchers," and other ornaments. Native Americans also used them as decorations, as it was reported that some individuals that met the pilgrims wore hummingbird earrings, and soldiers and missionaries in Mexico saw Aztec kings who wore cloaks made entirely of hummingbird skins.

The hummingbird family includes over 300 species and is the second largest family of birds after the flycatchers. South America has the greatest variety, with Ecuador housing 163 different species. There are over fifty species that regularly breed in Mexico, sixteen that breed in the United States, and four species that breed in Canada. Only the ruby-throated hummingbird nests east of the Mississippi River, however, although other types occasionally wander through. Hummingbirds range in size from the bee hummingbird of Cuba that weighs about 2.2 grams and has a length of only 2.25 inches to the giant hummingbird of South America that weighs about 20 grams and is about 8 inches in length. The ruby-throat weighs about 3 grams (about 1/10 ounce) and is about 3 1/2 inches from the tip of its beak to the tip of its tail.

A hummingbird has a muscular body and extremely flexible wings with the elbow joints very close to its body. It can rotate its wings in a circle, a characteristic that allows it to fly both forwards and backwards, as well as up, down, sideways, hover, or even upside down for short distances. Ruby-throat wings beat about 55 times per second, while other species sometimes beat up to 80 times per second, and during courtship dives have been clocked at up to 200 beats per second. The average life span is three to four years, although most die during their first season. The longest known surviving ruby-throated hummingbird was a banded bird that was 6 years 11 months old.

The highly iridescent feathers of a hummingbird throat are among the most specialized of all bird feathers. They have tiny sub-feathers that are smooth and flattened and packed with layers of tiny platelets filled with air bubbles, producing hues which are not dependent on pigment but on interference coloration, such as that seen in an oil film or soap-bubble.  In hummingbirds, 8 to 10 such layers are tightly stacked on top of one another and give hummingbirds the most intensively iridescent feathers known in birds.

Each spring we eagerly await the arrival of the birds that dine at our feeders, and the watch is on to try once again to find one of their nests. Perhaps this will be the year!


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May 20, 2008: A Woodland Threat


When one drives about in southern Wisconsin viewing neatly maintained farms, small towns with super stores and exercise studios, and along miles of landscaped highways, it is easy to forget that the area is only a few generations from wilderness and subsistence living. The occasional incursion of a black bear or wolf is a stark reminder but few of us pay much attention to such visits, and it is only when one of the resident wild ones oversteps what we consider its proper place that we become aware that it even exists.

A sad case in point is the loss of two small pet dogs in an outlying subdivision recently, as well as the attack on our neighbor’s spaniel – all evidently the actions of local coyotes. These versatile predators eat primarily small mammals, such as voles, eastern cottontails, ground squirrels, and mice, but they will also eat birds, snakes, lizards, large insects and an occasional larger animal if they can manage it. Any unwary small dog and cat in its territory is fair game for a hungry coyote.

A typical coyote resembles a small lanky German shepherd, but several characteristics distinguish it from a dog. A coyote tends to be more slender, have wide pointed ears, a long tapered muzzle, yellow eyes, and an straight bushy tail which is carried low to the ground. The fur is usually a grizzled-gray color with a cream-colored or white underside, but the color may be somewhat variable. It weighs about 30 pounds and is an intelligent, adaptable creature with many interesting habits.

The coyote typically lives about six to eight years in the wild but has an annual adult mortality averaging 30-50%. It faces natural hazards such as disease, predation, and starvation, but many die from human causes such as hunting, trapping, and vehicle collisions. Litters are sometimes large, but only 5-10% of pups reach adulthood. Coyotes form loose family groups, not tight family packs like wolves. These groups may form for short periods, then break apart as food supply allows.  Usually the animals hunt alone or in pairs, and one may distract and chase small prey right into the waiting jaws of another. Coyotes can run at speeds of up to 30 mph for short bursts but can maintain a 20 mph lope for long periods.

The coyote is one of the few wild animals whose vocalizations are commonly heard. A typical call is two short barks and a long yodel, and at night both male and female will give high-pitched quavering howls as well as a series of short, high-pitched yips to keep in touch with other coyotes in the area. Usually they call from an open area where the sound can travel several miles. Yelping and barking are also common sounds, and huffing is usually used for calling pups without making a great deal of noise. The coyote's big ears provide very acute hearing, which is vital for detecting prey and avoiding danger.

Coyotes mate in February and the female usually digs a den or takes over a vacant woodchuck or other animal hole for the birth of her pups. About 60 days later, up to a dozen fully furred but blind pups are born. At first the male brings prey back to the den, but soon both parents must hunt to provide enough food for the growing family. At 2 ½ months the pups begin to learn to hunt, and by autumn, most are independent of their parents.

Coyotes were originally residents of the Southwest where they inhabited open grassland, but they have gradually moved eastward until they can now be found across the continent. They can survive and thrive in suburban and even urban areas as long as there is food and shelter available. Chicago researchers studied coyote populations in a seven-year period ending in 2007, and estimated that there are some 2,000 coyotes living in "the greater Chicago area". They reported that the animals subsist mainly on rodents, feral cats, and small pets, and were living largely undetected in all areas from parks to industrial sites. As a testament to the coyote's adaptability, one coyote, dubbed "Hal the Central Park Coyote" was even captured in Manhattan's Central Park in March 2006 after being chased by city wildlife officials for two days. Coyotes can breed with domestic dogs, and the pups, called Coy-Dogs, can be more dangerous as they often have less fear of humans while possessing the wild instincts of a coyote.

Coyote control has long been controversial. Farmers have often urged strong measures to eliminate livestock losses, and some sportsmen feel the coyote is responsible for any declines in game species. But environmentalists firmly believe that the coyotes are necessary to preserve the balance of nature because much of their diet is made up of destructive rodents. What is certain is that coyotes will continue to live around us and we must adjust our actions to accommodate theirs, as they seem quite able to adapt theirs to take advantage of any human lapses. No food of any kind should be left out that might attract them, and small pets should not be out-of-doors unaccompanied—especially after dark.

We enjoy the wild side of our farm and area, and willingly accept that we must share it with the original inhabitants—be they coyotes, skunks, rattlesnakes, ticks, chiggers—whatever. I must admit, however, that a wolf or bear might give me second thoughts! 


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May 13, 2008:  It's No Wonder Some of Us Sneeze!

My favorite time of a spring day, even when the temperature is barely above freezing, is the early morning just after dawn. The birds create a chorus of sound – so many that it is difficult to separate out any individual. The raucous red-wing cuts through, as does the occasional crow, but mainly it is a haphazard mixture of robin, song and chipping sparrow, cardinal and wren making up the singers. I scan the sky for clouds, as on the farm the weather is a major factor in determining the day’s activities, and now that the remaining wildflowers from the sale are snugly tucked back into the soil, the vegetable and domestic flower gardens await.

Luckily, the plants that are now coming into flower cause me only an occasional sneeze out-of-doors as I am not one of the 35 million Americans who suffer from hay fever. Trees, weeds, garden plants, and grasses release a great deal of pollen that causes problems for many people. Pollen is an ingenious invention of the seed plants, which first appeared over 300 million years ago. It frees them from dependence on water for fertilization, which is needed by the spore-reproducing plants like ferns. The tough outer wall of the pollen grain protects the delicate male cells until the grain reaches its proper female stigma.  There it produces a tube that grows through the female tissue to the egg and through which the male sperm cells travel so that fertilization can take place.

Pollen grains are microscopic, and any details must be studied through a scanning electron microscope. Each type has its own unique set of characteristics, which means that each species or plant family can usually be identified. This is very convenient for researchers as pollen grains which are washed or blown into lakes can accumulate in sediments and provide a record of past vegetation. Different types of pollen found reflect the vegetation that was present around the lake at various times down through the ages, and therefore the climate conditions favorable for that vegetation can be determined.

Pollen is the sperm of the plant world. Each pollen grain contains one or sometimes several non-reproductive cells and a reproductive cell containing two nuclei, one of which is a tube nucleus that produces the pollen tube and a second nucleus that divides to form the two sperm cells. The cells are surrounded by a cellulose cell wall and come in a wide variety of shapes. Most are basically spherical, oval or disc-shaped but the surface may be smooth or meshed, grooved or spiny, and may contain pores or furrows. The respiratory systems of many people are sensitive to these, particularly those of the wind-pollinated plants that must produce masses of pollen to ensure that at least some of it reaches its target. Grass pollen affects about 95% of all hay fever sufferers, and birch, oak, and nettle pollen are also well known for their allergenic properties. Giant ragweed, which has been found to spread up to 8,000 million pollen grains in just 5 hours, is one of the worst.

The majority of flowering plants are insect-pollinated, however, and they produce smaller quantities. As an enticement, many plants secrete nectar, a sweet substance the insects or other creatures relish as food. Approximately 90 cultivated crops are dependent on insect pollination, and bees are responsible for about 80% to 90% of this activity. As a worker bee makes her way from plant to plant, pollen accumulates on her body and in special "baskets" on her legs that then often rubs off onto the female parts of the next flower she visits. This pollen is often sticky to adhere to the bodies of insects and can form clumps making it visible to the eye, which often makes sufferers assume that this is what is causing their symptoms. While such pollen does have allergenic properties, the chances of it reaching the nose are usually slim, and it is usually the wind-pollinated species with their insignificant flowers often producing millions of pollen grains that cause the trouble.

Plants use additional means to attract other insects such as perfume and color. Moths and butterflies can detect odors; therefore, often the flowers they pollinate are sweetly fragrant. Butterflies perceive many bright colors while moth-pollinated flowers are usually white or yellow -- colors which stand out at dusk or night -- and usually have a heavy, distinctive fragrance as well. Bird-pollinated flowers are usually large and bright red or yellow but need little odor since few birds have a developed sense of smell. In the continental United States, hummingbirds are the most common pollinators among the birds. They prefer tubular flowers whose petals are recurved to be out of the way, blossoms that provide support for perching, and those that are open during the day. Hummingbirds have very good eyes and can spot a promising red flower (or feeder) from some distance. They thrust their long slender bills deep into the flowers for nectar, withdrawing faces dusted in pollen.

Warm sunny days are best for pollen distribution, either by breeze or insects, and the weather has not been too cooperative this spring. The flowers have responded by closing their petals around their stamens on dark rainy days, thus protecting and preserving their pollen for better conditions. When the sun does shine, the plants will be a-buzz with bees and butterflies and the miracle of fertilization will take place, ensuring that a new generation in the form of seeds and then seedlings will be created. Another growing year has begun.

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May 6, 2008:  Are These Creatures For Real?

We were pleased by two long anticipated springtime events this week.  The first was the discovery of black morels on the hillside above the wild garden, and the second was the arrival of the first hummingbird of the season at our feeder. Hummers have been reported in numerous spots around the state this past week and I put out two feeders in case one happened by. There aren’t too many sources of suitable nectar available in our garden right now and we assume the tiny birds will be desperate for food.

I also read that a Wisconsin crane-watcher has counted eleven active whooping crane nests so far this spring. These are the work of birds that are members of the new migrating flock that were led to Florida by ultra-lites in years past. Last breeding season there were three nests with one chick surviving to make the flight south, so hopefully this year, as the birds become more experienced parents, there will be more. At this writing, three of the nests have been abandoned, but if the remaining nests produce even one chick apiece, it could bring the flock to a total of 80 cranes by autumn.

Warmer weather will be particularly welcome as I need to get my plants out into their summer quarters. Lovely as the greenhouse appears, it has become infested with intruders that are causing no little grief. Slugs and sowbugs are ancient creatures that play beneficial roles in our woods and prairies, feeding mostly on decaying plant material and acting as clean-up crews, but in the year-around summer of the greenhouse, they have become creaturae non grata. They have taken up new homes in my orchid and other plant pots and expanded their diet to include not only the plant roots but climbed up and feasted on blossoms as well.

A slug is basically a snail without a shell.  Lack of this covering makes it more vulnerable to predators and to drying out, but allows it to take advantage of very small hiding places such as under loose tree bark, beneath objects lying on the ground, and in flower pots. It moves about by gliding along on a muscular foot, which is lubricated with a slippery mucus that reduces friction and also helps reduce risk of injury from sharp objects. It has two pairs of tentacles on its head, the larger two equipped with light-sensitive eyespots and the lower set containing organs of smell. Both pairs are retractable and can be re-grown if lost.

Each slug has a mouth on its underside containing a rough, tongue-like organ that is equipped with many tiny outgrowths that are similar in structure to teeth. It uses these to scrape tissue from any edible surface on which it finds itself and one has ruined a number of my orchid blossoms in the process. Slugs have both female and male reproductive organs, and once a slug has located a mate it lies side-by-side with him/her and they exchange sperm. A few days later, both animals lay around 30 eggs, and then repeat the process about once a month throughout the summer.

Sow bugs are tiny crustaceans that also feed on dead or decaying plants or animals, but will eat live plants when available. They have three body parts as do insects -- a head, a thorax and an abdomen -- but the thorax is divided into seven separate segments and their armored exoskeletons remind some observers of armadillos.  They also have seven pairs of legs, two sets of antennae (one prominent and the other inconspicuous) and simple well-developed eyes.

Female sowbugs lay eggs that they carry in a pouch underneath the body, and the hatchlings resemble adults except in size. They remain in the pouch up to 2 months after hatching and take about a year to mature. Sowbugs must spend bright daylight hours in damp dark hideouts because they breathe with gills, but at night they venture out to feed. In the greenhouse, we often find them among the roots of precious potted plants, leaving holes in potting media and roots alike. Hopefully, those plants that can go into the ground will soon recover, and the others in pots will dry out to the point so that these animals will not survive.

Our wild garden is about two weeks behind the development that we have seen the past couple of years, so that some plants that are often through blooming by this time are still yet to come out. Those that have, such as bloodroot and hepatica, have lasted longer than usual, however, and barring a sudden transition to summer, we should have weeks of woodland flowers to enjoy yet.

After a busy month of digging and potting, the open houses are now over for another year. We enjoyed the opportunity to see many of you again and to share stories and wildflowers. We always welcome company, however, so come visit us anytime and walk the trails.


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April 29, 2008:  What's In A Name?

Trout lily, fawn lily, dogtooth violet, and adder's-tongue are all common names for a beautiful little plant in our woods, more properly labeled Erythronium albidum. Why the fancy moniker? Many of our wildflowers, as well as most other plants, have been given local names through the years and in order to make some kind of sense of the muddle, a system was adopted for accurate identification. Firstly, Latin was used as it is no longer spoken and can be considered a universal language. Then each individual species was assigned several names, the first referring to the family, such as orchid, and the second and sometimes third and fourth to specify the individual. For instance, consider that the yellow lady slipper is Orchidaceae (orchid) cypripedium (ladyslipper) calaeolus (yellow) pubescens (I don’t know the derivation of this word but it tells us that the plant is the largest of three known similar species). 

Most of us use the common names, however, confusing as they may be. Consider that trout lily. It reportedly was given that name because its mottled leaves are speckled like trout. However, although young plants consist of a single leaf, as they age they grow two and this led to the name "fawn lily". (This pair of leaves inspired naturalist John Burroughs to write, "Its two leaves stand up like fawn's ears, and this feature, with its recurved petals, gives it an alert, wide-awake look".) The name dogtooth violet is even more perplexing as this plant is definitely a lily not a violet, and it is only when looking at the plant's underground bulb can one see the resemblance to a tooth. Even then, why pick a dog? Another name is "adder's-tongue" and it is even harder to see any relationship between a snake's tongue and this wildflower. It is more likely that the plant reminded European settlers of some plant from the old country with that name. Sometimes reverting to a Latin term makes sense.

Virginia bluebells obviously get their name from their spectacular flowers, although they obviously are not restricted to that state. Another common term is "cowslip" and what kind of a name is that? It actually has its origin in the Anglo-Saxon word cuslyppe, cu meaning cow and slyppe for slop or dung, and you will have to use your imagination as to why anyone would so name such a lovely plant. It is possible that the ground in which these wildflowers often grew reminded early European settlers of pastures laden with cow-slop.

Consider the bee-balm. It is true that bees and other insects are attracted to its flowers but the truth is that bees have trouble getting the nectar from their deep throats and butterflies and hummingbirds are much more likely to feed successfully from them. Another name, "Oswego tea" refers to the use of its leaves in making a strongly mint flavored drink, and its abundance in the Oswego region of New York near Lake Ontario. It is also called "bergamot" from its fragrant resemblance to the bergamot orange, although it is no relation.

Perhaps you have wondered about naming of Solomon's Seal. In the winter when the leaf stalk dies back and separates from the rhizome, a scar remains which is said to resemble the seal of Solomon, king of Israel from 961 - 931 BC. The seal was a hexagram composed of two overlapping triangles to create a six-pointed star, commonly called the Star of David after King David, father of Solomon. The seal became synonymous with Solomon who reportedly used the symbol to cast away demons and summon angels. Solomon's plume, often called false Solomon's seal, and starry Solomon's seal are evidently named for their similar appearance to the larger plant, although they both lack the root scars that gave it its name.                      

The trillium and all its varieties are well named as their genus name is derived from "tri", Latin for "three". It has three broad leaves, three petals, three sepals, three-celled ovaries and its fruit, a red berry, features three ribs. Although there are other trilliums (trillia?) that grow in the area, none will be confused with the largest and showiest representative of the clan, grandiflorum, the large-flowered white trillium. A woodland carpeted with these white blossoms is a sight to behold. 

The Jack-in-the-pulpit sports a striped green hood or "pulpit" which curls over "Jack," the club-shaped organ at its center, supposedly bringing to mind an old time roofed pulpit. Its tiny flowers are either male or female and are located at the base of the “Jack”, and a fascinating fact is that the plant’s sex depends upon its age and conditions. If a large double-leafed female has a few bad years, the plant will often revert to one leaf and flower as a male, while good growing conditions can change a scrawny male into a large, multi-leafed female. So the Jack you see today may be a Jill tomorrow or vice versa.

Shinleaf is the rather unattractive name for a lovely little plant. It was once thought to be a cure for rheumatism and the leaves of this and other members of its family were used as plasters for bruised shins and other sores and wounds, hence the name. It is also called wild lily-of-the-valley, but I much prefer the scientific name of pyrola, rather than borrowing one from that garden flower.  The leathery rounded leaves of pyrola persist through the winter, and in the spring each basal rosette puts up a 6” upright flower stalk. It is very fragrant and even though the individual flowers are small, it often grows into colonies of some size and the combined scent can often be detected before any flowers are discovered.

All those flowers and more are on display and for sale at our final open house this weekend. Come visit us.


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April 25, 2008: Those Incredible Ants

Have you stepped on an ant today? Read this treatise and you may think twice about ever doing so again – or perhaps you will stomp every one you see as they may someday rule the world! Ants have very complex and varied biology. They live in colonies and this means that all the members work together selflessly for the common goal of colony growth and reproduction. In fact, some scientists suggest that an ant colony may be a single organism with the individual ants as its cells. Each nest contains at least one queen and thousands of workers, all of whom are sterile females. These workers care for the queen, enlarge, repair and defend the colony, care for the young and gather food. Some workers perform only one job throughout their lives while others may fill varying needs, with no one telling a particular ant what to do.

Ants communicate by touch and smell, but instead of sniffing the air, they use their sensitive antennae to detect and identify subtle smells. The waxy outer surface of an ant's body contains about 25 different hydrocarbons, each of which emit slightly different odors that provide important information. Each ant in the colony shares the queen’s odor, and when two ants meet, they smell each other with their antennae to determine friend or foe. Chemical signals seem to tell each ant what to do -- whether to stay in the nest and tend the young, build new tunnels, forage for food, guard the nest, or follow a trail to bring back food.

In 2001, a research group at Stanford University analyzed the chemical content of worker ants in the Arizona desert and discovered that if they captured and held the first ants that came out to search for new food sources in the morning, none of the others would emerge at all. However, if they dropped tiny glass beads coated with a chemical extract that contained the same proportion of hydrocarbons ordinarily present on a searcher ant, the waiting insects inside would touch the beads with their antennae, and somehow receive the signal that would bring them out to start work. As a control, the researchers also dropped beads coated with extract from nest workers or nothing, but these received no response.

A growing number of high-tech engineers are also interested in deciphering ants’ chemical reactions and applying them to such fields as telecommunications, computer networking, artificial intelligence and robotics. Ant research is even being used in an attempt to unravel secrets about the inner workings of the mind, comparing brain neurons that individually can do little but in concert with all the others can accomplish great things.

The largest ants are only an inch in length, but some species are lethal. The most dangerous are the army and driver ants of tropical forests that march around by the million, eating all the insects, spiders, and crustaceans that are unlucky enough to cross their path. Driver ants will kill and eat much larger prey -- even a disabled cow or a goat if it cannot escape. Another species builds a trap that consists of a platform perforated by holes where waiting ants hide, jaws wide open. When prey happens by they grab it and hold it fast until scores of other workers paralyze it with stings and dismember it.

Wisconsin ants are not really dangerous, although if you have stepped on a hill, you probably have found dozens of stinging insects crawling up your ankles and legs. However, they are extremely important seed collectors and dispersers. According to detailed studies of forests in West Virginia and New York, the seeds of no less than one-third of our woodland wildflowers are spread about by ants, among them beauties such as bloodroot, Dutchman's britches, trilliums, and trout lilies. These seeds have a common characteristic – they are equipped with a treat that no ant can resist.

Many seeds that are not carried off by the wind or attached to a passing animal by burs come wrapped in inviting fleshy fruits. In the case of some wildflowers, a whitish tissue that is full of proteins and sugars is attached to the outside of their seeds. I first noticed this on bloodroot seed upon opening a seedpod and seeing what I erroneously thought might be emerging roots. Later I discovered that foraging ants carry many of these seeds to their nests, where workers chew the tissue into pieces and feed it to the growing young. They then discard the seed itself, often carrying it off to an ant dump unharmed and leaving it to germinate in a new location.

Ants do other strange things than disperse seeds. Some farm aphids for their “honey dew”. Weaver ants hold their larvae in their jaws and squeeze them expel silk to bind leaves into a nest. Slave makers raid other nests and carry away the larvae to eat or raise to be workers. Parasol ants raise a fungus on chewed up leaves for food. Ants are found on every continent except Antarctica, and, despite their small size, are believed to make up about 10% of all animal biological mass worldwide. “Consider the ant…”

We hope to see you all at our open houses this weekend. I guarantee ants will be here.

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April 15, 2008: Have you Hugged a Root Today?

We are deep into dividing and potting up wildflower plants for our open house the end of the month, and it never ceases to amaze me how varied are the root systems of the different species. Some form masses of tiny filaments, some are sparse and wiry, others are thick and brittle, but they all serve two major functions – to absorb water and nutrients, and to anchor the plant to the ground. Often we are distracted by pretty flowers or unusual leaves and overlook a plant’s root system, but it is important to understand what is going on underground as the roots affect a plant's size and vigor, how and where it is likely to flourish, and what care should be given it. Roots will generally grow when conditions are hospitable with sufficient air, mineral nutrients and water to meet the plant's needs. At germination, roots lengthen downward due to gravity, and later increase in diameter. Over time, given the right conditions, some roots can spread with sufficient force to crack foundations, snap water lines, and lift sidewalks.

Roots typically lie deep below the surface of the soil, although this is not always the case: in fact, the only unique characteristic of a root is that it is the part of a plant that bears no leaves, and therefore lacks nodes. There are three major parts of a root. The tip is the major area of cell division and growth, and is protected by a cap that consists of cells that are sloughed off as the root grows through the soil. Behind the dividing cells is the zone where cells increase in size through food and water absorption, and as they grow, they push the root through the soil. Here are located the root hairs that are short-lived, elongated cells whose function is to increase the root's surface area and absorptive capacity. And finally, there is the zone that is directly beneath the stem where cells become specific tissues such as those that transport fluids and food up to the plant.

Many of the structures found below ground that we often think of as roots are actually modified stems (we know they are stems and not roots because they have nodes). Bulbs, corms, rhizomes, and tubers as such modified stems. A bulb is a shortened, compressed underground stem surrounded by fleshy scales that protect a central bud, such as in lilies and wild garlic. A corm is a solid, swollen stem whose scales have been reduced to a dry, leaflike covering, such as Dutchman’s britches and Jack-in-the-pulpit. A rhizome is a specialized stem that grows horizontally at or just below the soil surface that acts as a storage organ and means of propagation in some plants. We see rhizomes in Solomon’s seal, and bloodroot. A tuber is an enlarged portion of an underground stem that stores food for the plant.  It has “eyes” that are actually the nodes on the stem, and each eye contains a cluster of buds. Butterfly weed and wild quinine are plants that have tubers.

There are other modified stems that can be found above ground such as crowns, stolons, and spurs.  A crown is compressed stem tissue from which new shoots will be produced, and is generally found at or very close to the surface of the soil. Hepatica, asters, coneflowers, and many others of our perennial plants grow from such crowns.  A stolon is a horizontal stem that is fleshy or semi-woody and lies along the top of the ground. We often call these “runners” and they form new plants at one or more of its nodes. Wild ginger and wild strawberries are typical of plants with stolons. And finally, spurs are short, stubby, side stems that arise from the main stem.

I admit that the finer distinctions between these various root and stem systems are sometimes difficult to see, but it is storage structures that make it possible for us to transplant our wildflowers as we do. The sprouting plants draw on their stored energy to expand the compressed dormant cells that were produced during the last season until displaced roots can recover and take over the job of providing food. Many of the more ephemeral plants have a very limited time span to grow, flower, and set seed before competition for light, moisture, and space send them into dormancy for another year, and we try to reestablish them in the ground or pots quickly, to disrupt them as little as possible.

The cold wet days that have been vexing us lately are actually good for the wildflowers, giving them time to develop roots without having to support much top growth. One of these days, the sun will shine and the temperatures will warm, and suddenly the wild garden will be full of blossoms. The first hepaticas are already blooming despite the weather, but bloodroot, spring beauties, and the anemones will soon open their tight buds and spread their wares for bees and other insects to sample.

The variations in flower form are many -- among them bells, pendants, slippers – and wildflowers seem to come in every imaginable shape. Mark your calendars now to come to visit our wild garden during our open houses the weekends of April 26-27 and May 3-4. We have ordered good weather, and trust that the viewing will be spectacular. There will be hundreds of potted wildflowers from which to choose for your own gardens, and the Local Wood people are also holding field days here that first weekend, so there will be lots of activities for those of you also interested in managing your woodlands.


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April 8, 2008  Another Singer

The farm is our own private Garden of Eden complete with apple trees and plenty of serpents (and yes, I know that the fruit in the original story would not have been apples, and our snakes are not Satanic, but you get the idea). It only lacks one thing of being perfect – it has no water. Valleys on either side of us are blessed with springs that generate enough flow to eventually join to become Wilson Creek, but ours is dry. At various times, dousers have looked for water that might be near the surface, and we even cherished a “pipe dream” of building a dam across the bottom of the middle field and putting a windmill over the old well at the upper end to pump water for a pond. Nothing came of either of these ideas, but we did eventually get water on a very limited scale.

Our first pond was little more than a puddle off the side porch of the farmhouse, but for 20 years, it and its subsequent versions, have attracted birds and other creatures in our yard to drink. I dug it by hand originally and lined it with a plastic sheet, and now it houses water lilies and blue flags and is a joy much of the year. A small waterfall created by a recirculating pump not only provides a shower for bird visitors but makes music for our ears. We later put in a larger pond in the wildflower garden, and except for the renovating sessions that have occasionally been necessary, both ponds have proved very successful.

Having water brings an unexpected pleasure in the early spring, and last Thursday evening I heard the first songs of the spring peepers.  These are small brown treefrogs, the largest only an inch and a half long, that can be easily identified by the dark "X" on their backs. One fascinating thing about these frogs is that they survive the winter as chunks of ice. As the temperature drops, the frog drifts into a deep hibernation, its breathing and heartbeat stop, and as much as 65% of the water in its body gradually crystallizes into ice. Glucose in the cells seems to act like antifreeze to prevent damage even though its body temperature can drop to as low as 20*F, and when spring finally arrives and the ice melts, heartbeat and breathing return, and the frogs make their way to any nearby water to breed.

Frogs, toads, and salamanders are amphibians, cold-blooded animals with backbones that live part of their lives in fresh water and part on land. They are unlike fishes in that most types have legs instead of fins and generally breathe through lungs and skin instead of gills. They are different from reptiles because they lack a scaly covering and are able to take in water and oxygen through their moist, supple skins. Because their natural environments are streams, marshes, and low-lying meadows, these fascinating creatures are scarce in our high-and-dry hills, but a few species have flourished since we built our two ponds. Spring peepers, an occasional leopard and green frog, and toads migrate to them each spring to find mates and lay their eggs, singing all the while.

The spring peepers leave their woodland hibernation sites in late March or early April and perch on grasses and sedges at the edges of both ponds. The sound can reach deafening levels, far out of proportion to their tiny bodies, because of the remarkable air sacs on the floors of their mouths. These sacs act as resonators when they are expanded, like the hollow body of a violin, and, by