Our insect of the week for September 29, 2025 is another blister beetle. This time, we focus on Meloe impressus. This species was described by Kirby in 1837. William Kirby was an English entomologist who was also a country rector. He wrote a 4 volume “Introduction to Entomology” with William Spence.

The common name is oil beetle. As with similar blister beetles, when threatened, they release droplets of haemolymph (their blood) from their joints. the blood contains cantharadin which is a blistering agent. Larvae are hypermetamorphic with the first instar being a triungulin. These typically rest on flowers awaiting a bee to attach to. Once in the nest of the solitary be, they consume the bee egg/ larvae along with the provisions the mother bee left for her offspring.

The adult beetle in these stacked photographs was collected by Mark DuBois in June in Marshall County, Illinois. Lateral view is shown below, followed by a view of the beetle head.