Step aside, butterflies. We are going to take a moment to celebrate a lesser-known member of the Lepidoptera family. The big, colorful and beautiful cecropia (suh·krow·pee·uh) moth will surely take your breath away.
It is not only the largest moth in Illinois, but also the largest in North America. These moths prefer suburban areas versus mature woodlands, according to the Illinois Natural History Survey. That’s because the more urban an area is, the less likely this moth’s main predator, the white-footed mouse, is found. The more common house mouse cannot open the moths’ cocoons, making future generations of cecropia moths safe.
Let’s welcome this neighbor by learning more about what makes them so special.
What to look for
Keep an eye out for a wingspan of 5 inches to 7 inches, about the same size as the more popular eastern tiger swallowtail butterfly. Cecropia moths have red and white striped bodies. Their wings are brown with striking lines of white and red outlined in tan. Plus, they have crescent-shaped eyespots on their wings to help fool predators that they are always watching.
Cecropia caterpillars start out black with little bristles. As they grow, they become bigger by molting their skin. Molting means they shed their skin, like taking off a too-tight sweater. They will molt four times, growing to be 4 inches long. Each time they molt, they become more greenish-blue in color with rows of red, yellow and blue spiny tubercles on their bodies. These little horns have spines to help protect the caterpillar.
How to attract cecropia moths
Usually, a good way to attract butterflies and moths to your yard is by providing native flowers for nectar. However, cecropia moths are a little different because the adults don’t eat. They don’t even have mouth parts! Their goal at this stage is to find a mate and lay eggs. Therefore, it’s better to be a good host to the caterpillars’ needs. The adult females will be looking for the perfect place to lay 100 to 350 eggs. The goal is to find the right trees and shrubs that will provide the caterpillar with enough food to survive.
Words to know
Tubercle: A small, rounded protuberance, or bump
Nocturnal: Active at night
Cecropia caterpillars are going to be very hungry throughout this phase of their lives. They prefer trees and shrubs, including birch, box elder, elm, maple, white oak, apple and black cherry trees and lilac bushes. Once fully grown, the caterpillars will stop eating and head to the bottom of the shrub or tree to make a cocoon camouflaged in the twigs.
When to say hello
These moths are common from May to July. They spend the winter as silent pupae protected in their cocoons. Come spring, the adults will start emerging from their cocoons. Then they only live for five or six days, looking for a mate and a safe place to lay eggs. The eggs take 10 to 14 days to hatch. As caterpillars, you will see them eating away for four to eight weeks. Then they will spin their cocoon to stay hidden until next spring.
The key to getting a view of the short-lived adults is getting out at night. Cecropia moths are nocturnal. They are attracted to light, so it could be as easy as turning on your porch light to try to spot one. To level up your experience, try creating a light and sheet set up. Want to do some more mothing in your yard? Get some tips for a successful outing.
Want a little more help? Join us as we celebrate National Moth Week with “Moth Mania” from 8 to 10 p.m. Friday, July 23, at Hickory Creek – LaPorte Road Access. A naturalist will help you and your family discover what makes moths special and why we should celebrate this group of insects. Learn the different groups of moths, then take a night hike, sharing UV flashlights as we search for hidden insects glowing along the trail. Finally, we will check out our “research center” to see if we attracted any winged visitors. Register is required.
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