Crawling mysteries

Those who’ve grown up in suburbia don’t usually think of it as mysterious. Yet even our backyards are filled with mystery.
Take the caterpillar, for example. Stroll in your yard and you could quickly spot half a dozen kinds. Spend a little time, and you might find dozens.
But discovering caterpillars is a lot easier than naming them – or knowing what butterfly they become. And in a world that offers field guides to bird nests, mammal scat, and even roadkill, it’s surprising to learn that someone – in our backyard, almost – has recently written the first caterpillar field guide. UConn Professor David Wagner and his book, Caterpillars of Eastern North America, were profiled in the Aug. 8 New York Times.
Backyard caterpillar study has its advantages. The creatures can’t run or fly away, and you can, with little effort, raise most into their adult forms. You might even contribute to science since, as Dr. Wagner points out, there are moths – including well-known ones – whose caterpillars have never been discovered. It’s great fare for a natural history detective.

Clever caterpillars

In the late spring and early summer, many trees will shed some leaves just as dieting humans shed some pounds – to lose a little excess, unnecessary weight. But not all the leaves sent to the ground are the tree’s doing.

Trees are home to countless caterpillars, the larvae of moths and butterflies that dine on leaves. And searching the leaves for caterpillars are scores of hungry birds. Many, like chickadees, will look for damaged leaves, sensing that where there are holes, there are caterpillars nearby.

As defenses against birds, some caterpillars taste bad, grow spines or hairs, or bear bright “warning” colors. But in one of the little miracles of evolution, many edible caterpillar species have developed a different defensive technique. When they finish munching on a leaf, they clip it off and let it fall to the ground so it won’t give away their location to a bird on the hunt.

They don’t cover their tracks, they drop them.