By Debbie Roland and Emmy Ulmschneider, Master Gardeners
Last year when the monarchs were migrating, I wondered where the rest of the butterflies spend the winter. After some research, it seems that it depends on the butterfly because some do not migrate. It also depends on the life stage, whether it is an adult, caterpillar, chrysalis or an egg.
So first some butterfly basics. There are about 17,500 species of butterflies in the world and around 600 species show migratory behavior but migration in butterflies is poorly understood. There are about 750 species of butterflies in the United States and the number of butterfly species increases as one goes south to Mexico and the tropics.
Most of us are familiar with the epic Monarch migration. Each fall, the eastern migrating Monarch butterfly flies south from Canada through the United States to their overwintering site in Mexico. And in spring, the Monarchs start their journey north.
But there are other species of butterflies that make long distance flights. These species spend summer in temperate North America but cannot survive northern winters. They move southward in response to shortening day length and spend winter in a semi-tropical area. Some of their population returns northward in spring to repopulate an area.
So, if winter temperatures go below freezing and you do not migrate to a warmer place, how do you survive the winter? The other strategy is that you have one stage of your life cycle: egg, caterpillar (larvae) chrysalis, (pupa) or adult that is resistant to the cold. Adults that do not migrate, caterpillars and chrysalises go into something called diapause, which is their version of hibernation. Functions that are non-essential just shut down and their system slows down dramatically. Oddly, they also produce chemicals that are a lot like antifreeze until Spring arrives. Look for these overwintering stages in tree bark, under rocks, in fallen leaves, dense shrubbery and other places that are protected from the weather.
Insect populations, including butterflies are declining worldwide. There are roughly 23 species of common butterflies in our urban yards. Help them find shelter by leaving your leaves on the ground and being slow to take down dead plant material. Avoid chemicals in your yard and turn outside lights off at night. Artificial light disrupts insect’s lives. And consider planting natives in your yard so that butterflies, pollinators, and other urban wildlife have the resources they need to survive.
If you have questions, please call the AgriLife office in Odessa at 498-4071 or in Midland at 686-4700 for more gardening information. Additional information is available at https://aggie-horticulture.tamu.edu and westtexasgardening.org.