Monday, October 6, 2008

Insect Deadline

The insects of the Midwest are approaching their deadline. With the first freeze only a week or two away, they are busily ensuring the survival of their genes. Most species do not overwinter as adults and must mate and deposit eggs before they, themselves, succumb to the cold.

Our current, balmy interlude is providing a perfect opportunity and the chorus of cicadas, crickets and katydids made last evening sound like August. Warm, sunny days have the bees combing the flower beds and the dragonflies making their last forays of the season. Harvestmen roam the woodpiles, butterflies still brighten the shrubbery and flying insects attract squadrons of chimney swifts, soon to depart for southern climes.

While honey bees overwinter in hives, pregnant bumblebees retreat to underground dens and some species survive beneath leaf litter or in man-made structures, most adult insects will die with the first hard freeze. Their species will live on in the eggs or cocoons attached to vegetation or as larvae in the ponds or soil. Come spring, those not eaten by birds, moles, mice and shrews will give rise to the next generation.