Not every day I come across oil in my Dartmoor garden
I HAVE struck oil in my garden. Not a case of a well-placed spade in the lawn sending a raging geyser of slick crude high into the sky. Were that unlikely scenario the case I wouldn’t be sat here writing this, but instead slapping my thigh with a stetson hat, dollar signs in my eyes, trying to work out how to cap the fountain and build a nodding donkey from the scraps of wood in my shed.
Instead it was more modest in scale – droplet-sized in fact. A glossy bead of black lumbering across the grass: an oil beetle.
Oil beetles are one of our more bizarre insects in terms of appearance, given they have a remarkably distended abdomen, and also have a unique lifestyle, as their young climb flowers and hitch rides on wild bees back to their nests where they feast on the colony’s stores.
There are several oil beetle species in the UK and the similar-looking violet oil beetle and black oil beetle are the most widespread and can be locally common in wildflower grassland and heathland habitats. Both grow up to 3cm long and are black, but can have a purpleblue sheen, and this is a good time of year to spot them.
They are known as oil beetles not because they are the same colour as dark gleaming oil, but because as a defence mechanism they release caustic oily droplets from their joints which
can cause blisters – hence they are also known as blister beetles.
Mine was a violet oil beetle, which has a telltale notch at the rear of the thorax. A really characterful critter and smart too – slick, I guess one could say.