Our insect of the week for March 2, 2026 is Euclemensia bassettella, the Kermes Scale moth. [LEPIDOPTERA: Cosmopterigidae] It was described by James Clemens (an American entomologist; his collection now resides in the Academy of Natural Sciences in Philadelphia) in 1864. Yes, the Civil War was still raging while this species was being described.

When we examine the life of this species, things get rather strange. It is found in various parts of North America (including Illinois). This species lives in oak trees infected with scale insects. Adults have been observed flying from April (in Florida) through October (in Florida and Texas). In central Illinois, adults are most often observed in July and August. They fly at night and are often attracted to light sources.

What is strange is that the larvae parasitize scale insects in the genera Allokermes and Kermes. They are obligate internal parasites. Thy consume the body tissue of female scale insects and form a U-shaped chamber within their host. This is where they pupate. Who knew some moth caterpillars in central Illinois parasitize select scale insects?

The specimen shown in the photo was collected and photographed by Frank Hitchell in Peoria County, Illinois.