How Butterflies and Bugs Hibernate
Butterflies and bugs make themselves at home nestled under leaves or hidden beneath tree bark in the backyard.
Monarchs perform one of the most famous migrations in the world, but not all of their fellow fliers escape to the south. Most butterflies and most other insects don’t migrate. They’re hidden in the landscape in various stages of their life cycles for the winter months. Here’s how and where some of your favorite backyard guests withstand the chilly weather.
Butterflies and other bugs use various mechanisms to make it through the brutally cold months. They slow their metabolisms way down in a process called diapause. Certain chemicals in their bodies act as antifreeze. And they rid their bodies of nearly all water to avoid turning into an ice crystal.
Some butterflies hibernate through winter as adults. Mourning cloaks, question marks, commas and others hunker down, tucked away behind loose bark or in fallen leaves. But most spend the season in other stages of their life cycle.
Fritillaries, crescents and many skippers hatch in the fall and sleep through winter as caterpillars. Other species, such as coral hairstreaks and Karner blues, overwinter as eggs and hatch the following spring. Viceroys, also known as monarch look-alikes, employ an entirely different tactic. Caterpillars from the summer’s last brood create shelters called hibernacula. The itty-bitty caterpillars instinctively know to chew a leaf in a specific pattern, then fold and fashion it into a tentlike structure. The rolled leaf is lined and fastened to a stalk with silk the caterpillars spin themselves. Other caterpillars, like the beautiful and well-known swallowtails, reach full size and form their pupa, or chrysalis, before winter sets in.
Common backyard bugs persevere in similar ways. Many moth and beetle eggs, for example, are hidden in rough tree bark or under leaf litter. Praying mantis eggs stay safe and cozy in insulated egg sacs. Most dragonflies in their wingless nymph stage survive the cold underwater. And if your house
has ever been invaded by swarms of lady beetles or stinkbugs in fall, then you know their overwintering strategy all too well.
The more habitat you supply for butterflies and other insects, the more robust with flying creatures your spring garden will be. It’s as simple as not being too tidy. Dried plant stalks and seed heads offer hiding spots for insects, so go easy on deadheading. Stacks of firewood, brush piles and leaf litter also make a backyard more desirable to bugs. Before you know it, higher temps wake backyard insects, and your space comes alive again.