The largest moth in North America: the cecropia moth
Introducing the largest moth in North America — the cecropia moth! In addition to the trees and shrubs we grow in our Heritage Nursery, we’ve also been growing this spectacular moth.
In early August of 2018, one of our Heritage Nursery staff members noticed a colorful caterpillar feeding on New Jersey tea shrubs. Joe Stavish, Community Education Coordinator, identified it as a cecropia moth caterpillar. Tree Pittsburgh staff built a screen box around the plant to protect the caterpillar from hungry birds and parasitic wasps. For the remainder of the summer, the caterpillar fed and grew (molted). It spun a large silk cocoon in the fall to overwinter.
On Monday June 24, 2019, the moth emerged! This moth is a female, determined by its small antennae (male cecropia moths have larger, more feathery antennae which they use to smell and locate female moths from up to one mile away).
What is so special about the cecropia moth (Hyalophora cecropia)? It’s the largest native moth in North America with a wingspan up to 7 inches across!
Adult cecropia only live about a week, relying on their fat reserves to survive. They are incapable of eating. The sole purpose of their adult stage is to mate and lay eggs. The caterpillars are also harmless, and despite feeding on leaves all summer, their naturally low abundance prevents significant damage to plants.
A female cecropia can lay more than 100 eggs, which she attaches in small groups on the leaves or stems of various host plants and trees including apple, ash, birch, box elder, cherry, elm, large, maple, poplar, sassafras, and willow (to name a few).
If you’re lucky enough to see one, there’s no need to freak out! Simply take some photos and enjoy the moth’s beauty — and maybe turn off your porch light so they can go about their business.