Drawing On Science
by Stephen Yaeger
Have you ever wondered where insects and other guys go during the winter months? With all this snow on the ground where do crickets, spiders, earthworms, and bees spend the winter? Many of these invertebrates (=no internal skeleton or spine) do not leave the area when there is a change of season from summer to winter. They spend the time sheltered away under rotting logs, in sheds or garages, a warm cellar, or under shingles. They will even spend the winter under a windowsill or under your bed.
Butterflies and moths are usually found as pupae (=a stage in metamorphosis). If you find a cocoon and open it you would most likely find a moth pupa. It would be shaped like a cigar and would emerge as an adult moth in the spring. Most butterflies spend the winter months as naked pupae. Other butterflies will overwinter as larvae, eggs, or even adults. Other insects such as mosquitoes, lacewings and centipedes may be found hiding under anything giving the animal protection. They, too, are waiting for the warmer months to resume their lives. Some spiders may be found as spiderlings (=baby spiders) inside a spherical cocoon. Other spiders of all ages may be found sleeping under silken blankets. If you are looking for ladybird beetles—commonly called ladybugs—you may find hundreds sleeping in a cavity of a tree or rotting log. Ants and termites may be found hibernating inside a decaying log. In fact many arthropods (arthro=jointed, pods=legs) will spend the winter months hibernating or resting inside decaying wood waiting for the winter to end. Bumblebee queens and some wasp queens will spend their sleeping months within a log sleeping in a chamber that they carved out.
Have you ever turned a click beetle over on its side? Almost immediately the beetle will snap itself up into the air. But it you were to look for the same beetle during the winter, you would have to find its hibernation shelter in a log too. These guys come in all sizes and colors. Most of these beetles reach a length of about 1/2 inch. Some are smaller and some are larger. A large, gray, two-spotted click beetle about two inches long is the eyed-click-beetle. It takes this guy some three years to go from egg to adult.
Snails and slugs also overwinter by hibernating. Turn over a large stone, piece of wood, brick, or any object that is lying around in your backyard and you may find a snail. Pick it up and notice the dried mucus covering the opening of its shell. This dried bit of mucus is a patch keeping the snail safely inside its shell. Sometimes you may see dried mucus trails that lead to, perhaps, a decaying piece of wood. Examining the wood you may find a patch of mucus. This patch is actually a seal closing a small chamber. Within this chamber is the slug, which is completely covered in a mucus coating. The slug secreted the mucus for added protection while it hibernates.
Not all invertebrates spend their winter in one place. Many invertebrates will migrate to warmer climates where they will settle until it is time to return. The Monarch Butterfly is one such traveler. As the days get shorter and the air becomes colder, these guys will congregate into large masses.
They come from anywhere that milkweed grows—it’s their “steak and potatoes” so to speak. Then they break up into groups and head south for warmer climate. Sulphur butterflies, those little white butterflies that are so very common, also fly south. But some stay behind during the winter. They hibernate as adults or even pupae waiting for the warm weather of spring.
Japanese, May and June beetle grubs (=larvae) burrow below the frost line to spend the winter comfortably sleeping. When one gardens in the early spring, these grubs are often exposed. You may find a housefly or two buzzing around the house during the winter. Flies will remain in cold areas in a house, but sometimes become active and we see them flying around. Normally they remain in the cold area ready to lay eggs as soon as spring arrives. Questions/comments? E-mail Steve: Drawingonscience@ aol.com.