Where Do Bugs Go in the Winter?
By Marilyn Shy
The days are getting noticeably shorter, and one benefit that is greatly appreciated for those of us who spend a lot of time outdoors is the lack of bugs. It saves us from swatting and cursing and applying more bug spray (which doesn’t work all that well in the first place). We can breathe in the brisk fall air and just enjoy these cooler days to the max.
So where have all the insects gone, anyway?
Bugs have a variety of methods for surviving the cold and the harsh extremes of winter. Migration is one strategy. The Monarch Butterfly is famous for its long migration from Canada and the northern U.S. to a remote location in Mexico. But other insects also migrate from northern areas to southern states, including many crop pests.
There are also quite a few insects that overwinter as larvae. They burrow into leaf litter or deep into the ground. Some even replace the water in their bodies with glycerol as a type of antifreeze.
Not many insects stay active in the winter, but the nymphs of dragonflies, mayflies, and stoneflies live in the waters of ponds and streams, often under the ice. They feed actively and grow all winter to emerge as adults in early spring.
Some insects lay eggs which survive the winter. Two common insects which use this survival strategy are the Praying Mantis and the Corn Rootworm
A few insects overwinter as pupae, then emerge as adults in the spring. Moths in the silkworm family are active in this category.
Lastly, many insects hibernate as adults. Ladybird beetles are a well-known example. Some large wasps seek shelter in the eaves of houses and barns. The Mourning Cloak Butterfly is often the first butterfly to be seen in the spring, because it hibernates in tree holes or other shelters. As other insects that were already mentioned, it reduces the water content of its body and builds up glycerol which acts as an antifreeze.
In general, insects are able to survive cold temperatures easiest when the temperatures are stable, not fluctuating through alternate freezes and thaws. Blankets of snow benefit insects by insulating the ground and keep the temperature constant. Honeybees are found to remain semi-active in hollow trees through the generation of body heat by vibrating wing muscles. They also consume stored honey during the winter months, sometimes in large quantities.
The Kalkaska Conservation District and the AuSable Institute of Environmental Studies will be conducting some insect field work this fall. They will be counting nymphs of aquatic bugs on the tributaries of the Manistee River on Saturday, October 5th. The presence and quantity of these organisms helps to determine the health of our streams. Volunteers are being sought to help with these counts. No previous experience is required. Children are welcome, but the event is best suited for ages 10 and up. Equipment, including sample nets, will be provided, and waders are available upon request. Food and refreshments will be provided. For more information, contact Renee at (231)258-3307, or email her at: renee.penny@macd.org, or you may call Paul at (231)587-8686 or email him at: paul.w@ausable.org.