Monday, October 4, 2010

A Chilling Silence

For months now, I have walked to work amidst a chorus of insects. But, on the past few mornings, their chirps and buzzy calls have been stifled by cold overnight temperatures. With morning lows hovering in the upper thirties (F), these exothermic invertebrates have no energy for courting.

As the sun rises and the day warms, they resume their activity, focused primarily on procreation before a deadly freeze descends on the Heartland. Fortunately for them, the weather is expected to warm over the next week, offering a temporary reprieve and, for now, restoring the night music that is so characteristic of late summer and early autumn.

While most insects overwinter as pupae or eggs and many aquatic species spend the colder months as larvae beneath the ice, a limited number of adult insects (such as bees, harvestmen and ladybird beetles) survive winter in sheltered dens or beneath the leaf litter. But the adults of most insects die off with the first hard freeze, which explains their frenzied calls over the past few months. After all, their primary instinct, as with all forms of life, is to pass their genes to the next generation.