The Secret Life of the Oil Beetle

The UK has a number of species of Oil beetles. These flightless Coleopterans, all produce a thick, evil-smelling fluid, when they feel threatened. Oil beetles also have an extraordinary life history. When the female emerges, she digs chamber in the soil to lay numerous eggs. When the eggs hatch, the larvae emerge and climb up the stems of plants. Some will reach flowers. There, they can sometimes hitch a ride, by clinging to insects, coming to feed on/gather nectar and pollen. If that insect is a solitary bee species, the Oil beetle larvae is transported back to its nest. In that nest, it can feed on the bee's progeny, grow and complete its life-cycle. Sometimes, Oil beetle larvae finish up in Honey bee hives. Here they cause mayhem, as they can't leave. Oil beetles have to produce massive numbers of eggs, as most larvae will not be successfully transported by a suitable host.