Devil's Uber

Kelly’s Field Notes

Common Name: Devil's Coach Horse Beetle, Devil’s Footman, Devil’s Coachman, Devil’s Steed, Cock-tail Beetle, Large Black Rove Beetle

Order: Coleoptera

Family: Staphylinidae (Rove beetles, there are around 55,000 species described)

Genus: Ocypus

Species: Ocypus olens

Description: 

Larvae are long bodied, black, with fierce mandibles used to cut prey. Third instar larvae are between 2-2.6 cm in length (0.8-1 in). 

Adults are long bodied, black, and covered in short hairs. It has very short elytra which do not pass the thorax. Adults are about 2-3.2 cm in length (0.80-1.3 in). While it can fly for short distances it doesn’t often. Adults have flexible abdomens which they often raise over their heads in a defensive posture. While they can’t sting, they do stink! When threatened if the tail posture isn’t enough, they will puff out two white glands on their abdomen to release a noxious odor. Their bite is also quite painful. 

This species is very common across woodlands in Europe and North Africa, one of the larger beetles in the UK (the largest rove beetle in the UK). They have been introduced to the United States (the Pacific Northwest) and Canada (British Columbia). Larvae and adults are nocturnal.

The Bolus:

When larvae and adults feed they form a bolus. A bolus is chewed pieces of food mixed with saliva and digestive enzymes. Because the beetle cannot digest solids it needs to liquify its prey. It chews parts of the prey, swallows it, then regurgitates it covered in digestive enzymes and continues to chew until liquified. Any exoskeletons or worm-skins left are discarded. 

Life Cycle: 

Devil’s coach beetle females lay their eggs under moss, stones or other damp places (even cow manure). It takes about 30 days for them to hatch. Larvae are active hunters, feeding on other small invertebrates they find on the ground as well as pupae in the soil. It will take about 150 days for the larvae to go through 3 instars. After the third instar the larvae will pupate for 35 days, or overwinter in colder areas, then emerge as adults. Adults can live for about 2 years, as they sometimes diapause overwinter.

Devil’s Coach Horse Beetle in New Zealand:

New Zealand also has a Devil’s coach beetle (Creophilus oculatus) which is also a rove beetle (Family Staphylinidae)! This beetle looks very similar to the European O. olens we’re discussing in this episode. C. oculatans also emits a stink when threatened (which smells like rotten fish) and is an active hunter. It is often the first to arrive on carrion, waiting to feed on the carrion-feeding insects.

Super Powers:

• Flight. They have wings, though the forewings (elytra) are greatly reduced.

• Stinky!

• Powerful bite

• Deception. They pretend to be scorpions and generally appear fairly fearsome.

• Acid spit. Not really acid, but their saliva helps them digest externally.

Devil's Coach Horse Beetles in Culture:

• Medieval English belief that the Devil took the shape of this beetle to carry away the corpses of sinners.

• In English folklore if you crush a Devil’s coach beetle you will be relieved of seven sins (Please don’t do that!).

• Also in English folklore, this beetle was at the core of Eve’s Apple.

• Devil’s coach beetles are great in olive orchards, consuming many olive fruit fly pupae (Bactrocera oleae) before they can emerge and harm fruit.

References:

Albertini, Alice, et al. "Bactrocera oleae pupae predation by Ocypus olens detected by molecular gut content analysis." BioControl 63 (2018): 227-239.

Bonacci, T., Massolo, A., Brandmayr, P., & Brandmayr, T. Z. Predatory behaviour on Ground Beetles (Coleoptera: Carabidae) by Ocypus olens (Muller)(Coleoptera: Staphylinidae) Under Laboratory Conditions.

“Creophilus Oculatus.” Wikipedia, Wikimedia Foundation, 31 Aug. 2024, https://en.wikipedia.org/wiki/Creophilus_oculatus

‌“Devil’s Coach Horse.” The Wildlife Trusts, www.wildlifetrusts.org/wildlife-explorer/invertebrates/beetles/devils-coach-horse.

‌Wikipedia Contributors. “Devil’s Coach Horse Beetle.” Wikipedia, Wikimedia Foundation, 17 Dec. 2023, en.wikipedia.org/wiki/Devil%27s_coach_horse_beetle.