Luna moths color the night

by KEVIN STRAUSS

While some people think of moths as dull-colored and butterflies as bright colored, the luna moth (Actias luna) goes against this stereotype. Luna moths are lime green and this color helps them blend in with leaves and stay camouflaged while resting in the woods during the day.

Now is a good time to see bright green luna moths. These large moths have a four-inch wingspan and long curving Y-shaped tails. Your best chance to see luna moths (or most any other moths) is to watch porch lights after dark. Scientists believe that moths use light from the moon or stars to help them navigate at night. Our houselights and street lights seem to confuse and attract moths. You may also see moths resting on the sides of houses during the day.

Luna moths don’t eat as adults. They don’t even have mouths and they only live about a week. They got all of their eating done as larvae (caterpillars). Caterpillars feed on paper birch, aspen and willow all summer in northern Minnesota. The current logging practices that seem to favor aspen and birch forests provide plenty of food for this caterpillar. After eating as caterpillars, luna moths go into their cocoons in the fall. They hibernate during the winter and and change into big gree beautiful adult moths the following May. Since adults can’t eat, they have to mate quickly before they use up the last of the food energy stored in their bodies. The female uses the last of her energy to lay her 200 tiny white eggs on aspen and birch trees before she dies.

With only a week to find a mate and reproduce, luna moths can’t waste any time. Female luna moths release a pheromone scent to attract a male. Male luna moths use their feathery antennae to follow that smell back to the female. Scientists estimate that a male moth could track a female by scent up to seven miles away.

Luna moths are members of the “giant silkworm moth” family. Other members include the six-inch wide orange polyphemus moths and gray and red cecropia moths. Because of their size, these are some of our most familiar moths. While this group of moths have some similarities to the Asian silkworm moth, that is a member of a different moth family and is not native to North America. The giant silkworms weave large papery cocoons that are not suitable for the commercial production of silk.

Now that summer is here, keep your eyes open for these giant moths of the north.