Devil's Coach-horse

• When threatened it curls its abdomen upwards like a scorpion, opens its jaws and releases a foul-smelling secretion from two anal glands.
• Its tiny elytra conceal wings folded in an extraordinarily complex way, which it unfurls to fly and then packs away again beneath them.
• It is an ally in vegetable plots and gardens for its appetite for slugs and pest larvae, though its bite can be painful if it is handled.
• When threatened it strikes an unmistakable pose: it raises its abdomen over its head like a scorpion and opens its jaws wide. Hence its English name of devil's coach-horse and its reputation as a bearer of curses in British folklore.
• The display is only half a bluff: it has no sting, but it bites hard and gives off a repulsive smell from glands at the tip of its abdomen, which is what its name, olens, means.
• Its elytra are extremely short and leave almost the whole abdomen exposed, a hallmark of the rove beetles. Beneath those elytra it carries large wings folded in a highly complex way, which it unfurls to fly.
• It is a voracious predator of slugs, worms and insects, and in vegetable plots and gardens it is highly beneficial.
• Its larva is just as predatory and lives in the soil.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Gardens, crops, roadsides and leaf litter of Europe

Size at birth

Egg of 4 mm; the third-instar larva reaches 20 to 26 mm, almost the size of the adult

Sexual maturity

Mating takes place in late summer or in autumn and laying 2 to 3 weeks later

Gestation / incubation

The eggs hatch after about 30 days; the larva goes through three instars over about 150 days and the pupa lasts about 35 days

Litter / clutch size

Large eggs of 4 mm, white with a darker band, laid one by one under moss, stones, restharrow or leaf litter, 2 to 3 weeks after mating

Sources consulted: https://es.wikipedia.org/wiki/Ocypus_olens; Ficha de especie de Ocypus olens (Nield 1976); Buglife; Buglife, ficha Devil's coach-horse; Ficha de especie de Ocypus olens; observaciones de campo del Pacifico Noroeste; NCBI PMC9069170, genoma de Ocypus olens (Nield 1976); NCBI PMC9069170

Best time: Adults present all year, most active in spring; they overwinter in burrows and some do not come out until March