About Korynetes caeruleus (De Geer, 1775)
Korynetes caeruleus, commonly called the steely blue beetle, is a predatory beetle species belonging to the family Cleridae. The species name is sometimes misspelled as "coeruleus", but the correct spelling caeruleus is officially maintained by ICZN Opinion 604, published in 1961. Adult steely blue beetles measure between 3.5 and 6.5 mm (0.14 and 0.26 inches) in length. They have reddish-brown antennae, a faintly spotted brown head and pronotum, and shiny blue elytra. The larvae of this species develop in tunnelled wood that has already been infested by the common furniture beetle and the deathwatch beetle, and they feed on the larvae of these wood-damaging insect species. Finding Korynetes caeruleus in wood indicates that the wood has a heavy infestation of one of these two woodboring insect species. After mating, adult female Korynetes caeruleus lay eggs near or just inside woodboring beetle exit holes, then die. This species should not be confused with Necrobia violacea, another steely blue member of the family Cleridae. Both species are relevant to forensic entomology, though for different reasons.
