Fastest developing beetles

The fastest developing beetles of those currently studied are the round fungus beetles (genus Anisotoma) belonging to the taxonomic family Leiodidae. These beetles can complete their entire larval development on the ephemeral fruiting bodies of slime moulds in as little as two days. Round fungus beetles, as their name indicates, are commonly globular in shape (although a few species are more elongate), and feed upon fungi present in rotting animal or plant material, so are frequently found inside mammal dens and bird nests. Because they are often very small, less than 1 cm long (0.39 in), and dark/drab in colour, they can easily be overlooked. More than 3,800 species are currently known to science, and their taxonomic family, Leiodidae, is of worldwide distribution.

They are closely related to the rove beetles and the carrion beetles.