Evolutionary Sloth Moths
Sloth moths from Barro Colorado Island, Panama, in the NMNH collection. The card bears sloth fur to show the color proximity. Photo: Erin Kolski
In this fascinating article by Dr. M. Alma Solis, Research Entomologist at the National Museum of Natural History (Smithsonian Institute), Dr. Solis recounts the history of how scientists learned about sloth moths.
Back in 1907, during a Smithsonian Biological Survey of Panama, a Lepidoptera (moths & butterflies) curator noticed that when a sloth fell from a tree, many small moths flew out of the fur on impact. About 60 years later, other scientists realized that the caterpillars of the moths lived and fed on sloth dung, where their mother’s laid eggs. Since then, scientists have catalogued multiple species of sloth moths in different locations.
The subfamily of moths that the sloth moths belong to, Chrysauguine, is mostly filled with bright-colored moths whose caterpillars feed on plants. Sloth moths, on the other hand, have evolved to be dull-colored brown as camouflage in sloth fur. They also do not have the same ability to produce sound with their wings as other Chrysauguine moths. Perhaps the sloths appreciate the quiet!