I would have never noticed the monster of all caterpillars if I hadn't ducked beneath the heavily fruited blueberry branch that arched across the trail.


A motionless, fleshy hunk of spines clasped tightly to the blueberry branch was inches from my cheek. Its green, chunky, 4-inch-long body was armored with blue, white and yellow gladiator spikes. Its grotesque face displayed four knobby tubercles reminiscent of bright red lady beetles guarded with sharp black spines.

My face was armed with a grinning smile, for it was only my second encounter with this impressive larva of the largest silkmoth in North America — the cecropia moth.

The cecropia moth, Hyalophora cecropia, is one big insect. The terrestrial caterpillar is imposing in its own right, but the adult is something extraordinary.

At a glimpse, the adult's 6-inch wingspan fluttering against a moonlit sky can be mistaken for a bat.

When found at rest during daylight hours, the cecropia moth is stunning. Its chunky body is colored burnt orange with white stripes. Its broad, brown wings are marked with light tan crescents, dark brown eyespots and reddish bands. The outer edge of its wings are bordered in light tan. Males sport a pair of brushy antenna used for long-range pheromone reception, while the antenna of the fat-bodied females are noticeably less plumelike.

The cecropia moth is widespread in eastern North America, where it calls deciduous forests home. The hungry caterpillar consumes the leaves of many trees and shrubs such as cherry, maple, elm, aspen, birch, aspen, oak, willow, blackberry, blueberry and alder. Coincidentally, both of my cecropia moth caterpillar discoveries were climbing on highbush blueberry branches.

An amazing fact about cecropia moths: While the chunky caterpillars have dynamic appetites, the extremely large adult moths do not eat, as they do not possess mouth parts.

The sole purpose of an adult's brief two-week lifespan is to mate and deposit eggs. Females deposit hundreds of tiny eggs on the leaves and branches of its host plants.

After hatching, the tiny caterpillars feed heavily and go through several instars of growth. During their final instar, the caterpillar locates a twig or branch to build a large, leaflike cocoon which is remarkably camouflaged and difficult to locate. The plump caterpillar wrapped in its homemade leafy sleeping blanket will overwinter and metamorphose into a beautiful cecropia the following spring.

The threats to cecropia moths and caterpillars are many. Parasitic wasps target caterpillars and lay eggs inside their plump bodies, eventually killing them. Hungry birds and squirrels take their toll of cecropia larvae. Flying cecropia moths are attractive targets for bats, owls and other nocturnal fly-catching birds. Widespread pesticide spraying can be devastating on cecropia moth caterpillars, while habitat destruction takes its toll on local populations.

The next time you observe a cecropia moth, the bat-sized giant of the moth world, feel very fortunate, as they are not often encountered in the wild.

For me, it's always a delight to find a colorful, mouthless moth as big as my head, and equally rewarding to have a close encounter with a harmless, creepy-crawling creature that looks like a pickle of mass destruction.
