Friday, June 26, 2009

This prehistoric looking moth is the Carpenterworm Moth (Genus: Prionoxystus). They are found throughout North America. They are very common in Missouri. The one pictured here is a female. I have a mercury vapor light and a white sheet set out near our timber and it isn't uncommon to have as many as a half dozen of these large females on the sheet. I have yet to see a male. The wings are highly veined, looking almost like alligator skin or webbing. They are shades of gray, black or brownish-black. The males are different, their forewings are more deeply mottled and their underwings are bright yellow. Females lack any yellow coloration. After mating, females will lay her eggs near host trees. When the eggs hatch the young caterpillars will bore into the tree. It can take up to four years for them to complete their lifecycle. These caterpillar bore huge tunnels throughout the tree causing significant damage to the tree. If you were to uncover the young caterpillars you would discover a variety of colorations. They range from greenish to reddish with black spots and dark brown heads. Often times woodland exploration will bring a discovery of one these emerging from their timbered home as an adult. Look for them near woodland edges and within deciduous forests. The adults do not feed. The young caterpillars have a variety of hosts including Locust, Ash, Oak, Poplar, Chestnut and Willow. Because of their habit of boring into trees they are sometimes called Locust Borers. A close relative of this species (Comadia redtenbacheri) is the famous Agave Worm. This caterpillar gained fame for being the worm at the bottom of the Tequila bottle. Supposedly the worm was placed in the bottle of tequila, if the worm died before hitting the bottom then the liquor was considered unsafe to drink (go figure). Nowadays you will never find these worms in a bottle of authentic tequila.


  1. It means you have good knowledge about insects and bugs. This blog is also of great value for me. Hoping it will resolve my identification problem. Added to my blog list.

  2. Thank you birdy so much for your thoughtful comments, and for adding my blog to your list. Happy bugging and I look forward to hearing from you again. ;o)