Red-striped Oil Beetle

• GeneralIt secretes cantharidin, a toxic fluid that raises blisters on contact.
• Its development is a hypermetamorphosis: the newly hatched larva, called a triungulin, climbs onto a flower and hooks itself into the hair of a solitary bee, which unwittingly carries it back to its nest, where it devours the provisions and the eggs.
• It secretes cantharidin through the joints of its legs as droplets of haemolymph, in what is known as reflex bleeding.
• Its size and slowness make it very vulnerable to being run over and trodden on along tracks and paths.
• It secretes cantharidin from its leg joints, an oily fluid — hence the name oil beetle — that raises blisters and burns on the skin. It should not be handled, although it is otherwise harmless.
• Its black colouring with red or orange bands is aposematic: a warning that it is toxic.
• It undergoes hypermetamorphosis: it passes through larval stages of entirely different appearance. The eggs hatch into triungulins, mobile larvae with three claws per leg that actively search out the nests of solitary bees and wasps.
• Inside the nest they devour the bee's eggs and larvae and then the stored pollen and honey; afterwards they change into a very different-looking larva and finally pupate.
• Its wing cases are stunted and it has no wings, so it cannot fly. Disturbed, it plays dead.

Habitat & environment

Steppe, dry grassland and tracks

Litter / clutch size

Thousands of eggs per female, in a hollow in the ground

Sources consulted: https://es.wikipedia.org/wiki/Berberomeloe_majalis

Best time: Spring, walking along paths and dry grassland