The most beautiful insect of the summer is the luna moth and probably the most recognized member of the moth family. In 2007 a television commercial for the sleeping aide Lunestra was first aired and it is still being run today. The TV commercial uses the luna moth as its mascot. In the commercial the moth softly flutters in an open bedroom window on silent wings promising a good night’s sleep. I think that it is strange for the sleeping drug advertisement to feature an insect that is active only at night and sleeps during the day. Also, in 1987 the luna moth was placed on a twenty-two cent U.S. A. postage stamp that added to the moths’ popularity. These moths are fairly common. However, due to their nocturnal behavior they are seldom seen during the day because they sleep in secluded places. The one in the photograph was resting on the wall of Perry’s Raccoon Valley Bank Building. These insects range across the eastern two-thirds of the United States and southern Canada. It is sometimes called a lunar moth or an American moon moth. It belongs to the moth family called Saturniidae- the giant silk moths.
They are strong fliers and males will fly for hours during the night searching for a female. The females produce a chemical attractant called a pheromone that the males can smell from miles away.
It is difficult to tell the males the males from the females unless they are side by side. The males have a larger and bushier antenna than the females and the males have yellow-green wings but the females wings are a bluish-green color. I am fairly sure that the one in the photo is a female. Both have dark eyespots on their wings- perhaps this is a coloration technique to confuse or scare away predators. The moths are preyed upon by owls, bats, and bald-faced hornets.
The adult moths have only one function, which is to reproduce. They don’t eat anything during their brief life; they don’t have any mouth parts. If they are lucky they can live on the stored food from their caterpillar stage for about one week.
Human activity has caused some harm to these beautiful insects- pollution, insecticides, and loss of habitat has taken a toll on their populations. Also, some entomologists believe that light pollution, especially mercury vapor lights have disrupted their breeding habits, especially in urban areas.
After a pair of luna moths mate, the female will lay five to ten eggs in a cluster on the underside of a tree leaf and then fly to another tree and lay another small cluster of eggs. She usually lays about ten groups of eggs. The eggs hatch in a week and the green spiny caterpillars begin feeding on the leaves of the tree. They do very little damage to the trees on which they feed. They will shed their skin five times before entering the pupa stage and forming a cocoon. The caterpillar will wrap itself in a leaf and the seal the leaf with a thin layer of silk. The insect is in the cocoon for two weeks until the large green caterpillar changes in to a beautiful luna moth. In central Iowa there can be a late spring hatch and a late summer hatch of moth eggs. The caterpillars that are hatched in late summer or fall will survive the winter months in the cocoon stage to start the process over again in the following spring.