Nebraskaland

62 Nebraskaland • January-February 2026 MIXED BAG Insects are organisms that are ectothermic, or cold-blooded, which means they cannot produce their own body heat like mammals or birds. In order to survive and thrive in climates that can be as unforgiving as Nebraska, insects have developed several strategies to deal with frigid weather. Diapause Rather than hibernation, insects have their own version of this life- saving tool known as diapause. Insects that prepare for diapause, such as woolly bear caterpillars, will try to seek some kind of shelter for the winter, similarly to hibernating mammals. These shelters could be under rocks, in tree trunks, leaf litter or in burrows underground just a few inches beneath your feet. Migration One approach that insects employ is migration. For example, monarch butterflies in Nebraska are known to fly thousands of miles every year to venture to the same areas of the oyamel fir forests in the mountains of central Mexico. This microclimate is heavenly for these butterflies as temperatures don't get too hot nor too cold, and the area provides the butterflies the right amount of humidity to live until they can return north in spring. Eventually, the children or grandchildren of last year's monarchs will return to Nebraska. Freeze Avoidance When cold temperatures stay for long periods of time, insects utilize a freeze avoidance strategy. Some species of insects will enter a "dry" hibernation state, when they purge all the food and water in their bodies. This prevents ice inside their bodies from forming, which is deadly. Other species can produce cryoprotectants, such as glycerol and sugar, to reduce the lethal freezing temperature of their bodies. This concept is similar to the antifreeze found in your car. Many insects use this strategy if they are overwintering as larvae. Some species of grubs will burrow deeper into the soil to escape the cold. Other insects have a heavy, waxy coating on their exoskeletons that protects against ice formation. Overwintering as Nymphs Not many insects are active in the winter, but the nymphs of dragonflies, mayflies and stoneflies can live under the ice in ponds and streams. These insects actively feed and grow all winter to emerge as adults in early spring. Some species may stay in the aquatic larval stage for several years. Overwintering as Eggs A few insects lay eggs that can survive the winter, such as the praying mantis. Although most adults die during the late fall and early winter, the females leave behind a foamy- looking egg case, known as an ootheca, on rocks, twigs, stems or even on the sides of buildings or fences. Inside the egg case are dozens or hundreds of mantis eggs that can survive the winter due to the foamy insulation. As the weather warms in the spring, young mantids emerge. Even during a time when we don't see them, we can appreciate the cleverness of insects. Although most adult praying mantises die during the late fall and early winter, females leave behind a foamy-looking egg case, known as an ootheca. JENNY NGUYEN-WHEATLEY, NEBRASKALAND WHERE DO INSECTS GO IN WINTER? By Monica Macoubrie, Wildlife Education Specialist

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