Winter World_ The Ingenuity of Animal Survival - Bernd Heinrich [73]
The physical scientist tries to understand the world according to mathematical precision by reducing its composition and functioning to a very few “laws of nature.” Such laws, in analogy with our own civil laws, are as if handed down from some higher authority who then enforces them by virtue of that authority because a law is, by definition, general. It applies uniformly. There are no exceptions, or no exceptions are allowed.
Insects’ success is derived from exploiting individual specificity. No one way is best. Insects achieve their success through their diversity, where each individual case is special within the generalizations. Each species is adapted ever more specifically into a specialist niche, catering to specific individual needs. An ever-greater narrowing down to the specific has resulted in miniaturization, and ever-greater diversity. Insects exhibit an exhilaration and a celebration of the exceptions, where anything goes that can. There are few boundaries, because there has been no enforcement or encapsulation by or in laws. That is why they are so successful, and I suspect that it would be difficult to find an entomologist who is also a theist, who believes that there is a force or a power that hands down rules because “he” deems them good. No entomologist could fathom why fleas, mosquitoes, tsetse flies, migratory locusts, and dozens of other insects would have been deliberately created and let loose to cause indiscriminate and unimaginable agony to millions of totally innocent human children and adults over all the ages of humanity.
And it is this indiscriminate capacity to individually do what is best for them that has allowed insects to advance far into the winter world, one species at a time, to explore and exploit the many possibilities.
My fascination with insects started before I was ten years old, thanks to my father, who took me with him on winter adventures to look for hibernating ichneumon wasps. The white grub-like larvae of these insects feed inside (and eventually kill) caterpillars after the wasps inject their eggs through the caterpillar’s skin with their sharp hollow ovipositor (that also serves as the stinger in bees). Papa collected inchneumon wasps as passionately when he was eighty years old as when he was twenty. At that time he had only barely scratched the surface of their astounding abundance and diversity, even in Maine, and many of these exquisitely elegant creatures that keep other insect populations from exploding, still remained to be discovered.
Promethia moth caterpillar and ichneumanid parasite.
The males of these and almost all Hymenoptera, the family of ants, bees, and wasps to which ichneumonids belong, don’t solve overwintering. They simply all die by fall, by which time they are superfluous since the overwintering females are by then inseminated. Only the females seek overwintering sites in places where there is moisture so that they do no desiccate. Temperatures must also be low enough to dampen the metabolic fires and thus conserve the limited stores of energy that they lay up in body fat. As with most insects, however, temperatures cannot be so low as to cause freezing-injury. Typically when unadapted soft tissue thaws out after freezing solid, it turns into a brown mush. A quick routine way to kill summer-active insects (such as specimens for one’s collection, or the pests that are eating one’s collection) is by putting them into the freezer compartment of the refrigerator at about -10°C. This is a very modest temperature, relative to those that some species routinely survive in the wild, in northern winters.
An ichneuman wasp, of subfamily ichneumoninae.
We found the ichneumon wasp females at three kinds of overwintering sites. We had the most success finding a variety of species in the decaying wood of old moss-covered tree stumps. Other species turned up only under moss, and still