Most insects do not migrate, and even the ones that do can stay the winter utilizing a key skill called diapause. Diapause is the delay in development during periods of adverse environmental conditions. The strategy is a means of surviving predictable, yet unfavorable, weather. All our nonmigratory insects exhibit diapause during their lives—mature and healthy monarchs and swallowtails being among the few to depart to warmer zones.
Diapause can happen during any life stage and will often occur more than once as temperatures dip and rise in the spring and autumn seasons. Insects go through many life stages before they reach maturity and can enter diapause at any stage, lay eggs almost any time of the year, and graduate to adulthood on the strangest of days. Having a healthy balance of insects is extremely important to all things, as they are our major pollinators for food and crops as well as the trees that produce our oxygen and the gardens that make our spaces beautiful. This is not something that happens overnight, though it can happen generously in just a season or two by following a few simple rules and catering to the good.
During diapause, these insects need to be somewhere safe, as they are in most ways temporarily dead, unable to feed, move, or defend themselves. Their bodies produce a substance called glycol, which is akin to transmission fluid and keeps the moisture in their bodies from becoming crystalline or frozen. Without it, they would literally explode on the coldest days.
Leaving your garden debris and leaves is crucial to not only soil health, but also to the millions of microorganisms that live there. Insects lay eggs in the soil, on the underside of leaves, the crowns of plants, and in casings along the stalks of plants. They rely on leaves, gravel, rotting wood, and garden debris left over winter for their hiding place as well as for food and nutrients on the days they are awake. This fall tactic also greatly reduces your cleanup work!
Leaves and debris are helpful to leave until things warm up the following spring with days into the 60s and leaves on trees once again. Cleaning up or disposing of debris too early can take away all the hard work they did to habituate your space. Your plants will also like the nitrogen produced by the rotting leaves, exposing their crowns mid-spring, as leaf mulch is extremely beneficial to use in the garden and relatively free—no mowing or chopping needed.
Less labor, free mulch, better soil, and more beneficial insects is better for everyone! Among those to truly benefit are the lacewings, lady beetles, praying mantids, damselflies, ground beetles, bees, wasps, spiders, moths, ants, bats, and the whole family of brush-footed butterflies: mourning cloak, Compton tortoiseshell, Milbert’s tortoiseshell, question mark, eastern comma, and the grey comma butterfly. Some of these amazing insects only live 1 week, but many live for 11 months, even in Wisconsin.
Other things that can greatly attract and keep beneficial pollinators around are small areas of gravel or exposed soil, as they like the salt and nutrients that can be found there. They also like semi-rotting fruit and drinking areas they will not drown in, a large rock in a basin of water, for example.
Karina Mae is the designer and team leader at Garden Search and Rescue.
Garden Search & Rescue
Madison, WI
608.438.9571
gardensearchandrescue.com