A family of Clown Beetles
A Spotlight Specimens special for Oxford Festival of Nature
By Amoret Spooner, Life Collections
Within the order of insects Coleoptera – the beetles – is a family called Histeridae, also known as the Clown Beetles. This family is found worldwide and so far around 3,900 species have been discovered. Of these, 52 species are found in the UK and it’s these that I’m currently working on.
Histeridae aren’t the most appealing beetles to look at. They’re not very big, or round, and they don’t come in pretty colours. Basically they lack the wow factor… until you look at bit closer! Hister quadrimaculatus is probably the biggest and most colourful of the British species; it is black with four red dots (it’s all in the name).
Histeridae live in a variety of habitats, but are most commonly found in dung and carrion. Surprisingly though, they are not eating the dung or the dead animal; they are there for the fly larvae. Flies are attracted to decomposition, and the Clown Beetles take advantage of this. The adult female Histerid lays her eggs within these environments and three days later the larvae emerge to feast on the fly eggs and pupa.
Some of the more obscure species, such as the rare Haeterius ferrugineus live in ants nests, particularly those of the Slave-maker Ant (Formica sanguinea) and the Black Ant (Formica fusca). These types of Histerids vary in colour and modifications compared to the dung- and carrion-dwelling Histerids because they have evolved to live successfully with ants.
Another species that differs from the norm is Hololepta plana; as an adult it is completely flat, adapted to live under bark and feed on the larvae of other invertebrates.
The Histeridae are a wonderfully diverse family, and we’ve got some pretty amazing examples of them in the UK. They may not be beautiful to everyone, but they are fascinating creatures that play a vital role within our environment and we’ve got a lot more to learn about them.