Genus Brachinus - Bombardier Beetle

Brachinus is derived from classical Greek βρᾰχύνω [ῡ] = brachyno or βρᾰχύς = brachys with the accent on long upsilon. Both Greek variations denote "shortness", a reference to the the beetle's shortened elytra. The classical pronunciation for Brachinus would sound closer to bră-KOO-nŭs than the American English convention of bră-KĪ-nŭs. The accented long upsilon best approaches the sound of German ü as in über or Müller. Mid-20th century authors DJ Borror and CT Brues offered BRĂK-ĭ-nŭs, but that would be further from the ancient Greek tongue.

References: Liddell & Scott's Classical Greek-English Lexicon; The Century Dictionary. [PWM note]

Brachinus Weber 1801

48 spp. in our area, all in the subg. Neobrachinus; >300 spp. in 9 subgenera worldwide(1)

Canada 10 spp.(2), RI 12(3), FL 19(4)...

5-13 mm

Medium-sized beetles with dark (blue, green, or blackish) elytra that contrast strongly with orange head and pronotum; some are flightless(5)

worldwide (poorly represented in Australasia); throughout NA, much more diverse in the south (do not range north of 50N in the west and 45N in the east)(7)

under loose bark, rocks, boards, on ground in open at night; usually associated with floodplains, edges of temporary ponds

larvae are parasitoids of aquatic beetle pupae and scavenge body of host after its death

Eggs laid singly in mud cells made on plants, rocks. Larvae have reduced legs and pupate inside the host.

Adults have chemical defenses, ejecting toxic, foul-smelling gases from their abdomen with a loud popping sound. The explosive brew is composed of hydrogen peroxide, hydroquinone, and catalytic enzymes.