Saving the small things that run the planetThese aggressive, carnivorous predators are commonly found across the UK and Europe in a variety of habitats. The Devil’s Coach-horse can sometimes be mistaken for an earwig but when threatened its scorpion-like posture will give the game away! The Devil’s Coach-horse belongs to the rove beetle family, called the Staphylinidae which are sometimes referred to as the ‘Staphs’ for short. There are approximately 1000 species of rove beetle (given this name as they are constantly on the move) found in the UK which amounts to roughly a quarter of all British beetles.
Latin name: Ocypus olens
Notable feature: Long-bodied, uniformly black beetle with an extended exposed powerful abdomen with shortened wing cases
Conservation Status: Not Evaluated
The Devil’s Coach-horse is the largest of the rove beetles and can reach a length of around 28mm. Typical to this family, the Devil’s Coach-horse is a long-bodied, uniformly black beetle with an extended exposed powerful abdomen with shortened wing cases (elytra). Although able to fly its wings are rarely used.
The beetle is common in the UK and is found throughout Europe. It also inhabits parts of Australasia and the Americas but it is not native to these areas having been introduced.
The Devil’s Coach-horse occupies a wide range of habitats requiring damp conditions and is common in woods, hedgerows, meadows, parks and gardens, being seen between April and October. It is also known to make its way indoors now and then, particularly in older properties.
3,2,1….Fight!
If you have crossed paths with the Devil’s Coach-horse you may have seen it adopt its typical defensive pose where it raises the rear end of its body and opens its fierce jaws, similar to that of a scorpion. A tad on the aggressive side perhaps but it is only because its feeling threatened! If it continues to feel threatened though it can emit a foul smell from its abdomen area (‘olens’ meaning smell) via a pair of white glands; can excrete an unpleasant fluid from its mouth and rear; and it’s fair to say that its bite may hurt a little!
Jaws of the invertebrate world
During the day the Devil’s Coach-horse usually rests amongst and under stones and logs but it is at night that this carnivorous, nocturnal predator comes out to feed on slugs, worms, spiders, woodlice, a range of other invertebrates and carrion (dead items).
For its size the Devil’s Coach-horse has very large jaws (mandibles) which it uses to catch and cut its prey. With the help of its front legs the food is then turned into a ball like shape (bolus) which is chewed, passing through the beetles’ digestive system a number of times until it becomes liquefied and finally digested.
Little Devils – carnivorous young that live underground..
Devil’s Coach-horse mate in autumn and a female will lay a single egg two to three weeks later in a damp, dark habitat such as leaf litter or moss. After around 30 days the larva will emerge, living mainly underground. As with their parents, Devil’s Coach-horse larvae are carnivorous feeding on a variety of other invertebrates; possess powerful jaws to catch and consume their prey; and can even adopt the threatened display of a raised tail and open jaws. The larva goes through three successive growth stages (instars). The third and final larval stage is reached after approximately 150 days when it is between 20 – 26mm in length. It is at this stage that pupation begins and an adult beetle emerges about 35 days later. It emerges fully formed but needs to stay inactive for a few hours to allow its wings to dry out before they can be folded beneath the wing case (elytra).
If the weather conditions are mild adults can remain active and survive a second winter. Alternatively they will burrow underground and hibernate until the following March.
What’s in a name?
As far back as the Middle Ages this species has been associated with the Devil and was known in Ireland as Dar Daol which translates as ‘the Devil’s beetle’. Many myths and superstitions have surrounded the Devil’s Coach-horse such as its ability to curse a person by pointing its upraised body in their direction! Some also believed that the beetle had magic powers and it is believed by some that in Ireland reapers used to improve their skills by putting a Devil’s Coach-horse in the handle of their scythes.
The beetle has even achieved celluloid fame by starring in a film based on the aptly named 1979 book ‘The Devil’s Coach Horse’ by Richard Lewis, where the creatures get a taste for human flesh and go on the rampage.
Is the Devil’s Coach-horse good?
The Devil’s Coach-horse is a beneficial insect playing an important role in the food chain as a dominant predator, ensuring that nutrients are recycled and returned to the soil.
