COLEOPTERA > POLYPHAGA > HYDROPHILOIDEA > Hydrophilidae

This is a diverse family with around 70 British species that are nearly equally split between two very distinct subfamiles Hydrophilinae and Sphaeridiinae that have rather different lifestyles and habits.

The Hydrophilinae are largely aquatic, although unlike the superficially similar Dytiscidae (Diving beetles) are generally poor swimmers such that most species live in shallow water typical of marshes and similar wetland habitats with pools, or marginal situations where there are well vegetated areas around ponds or alongside streams or slow-flowing rivers.

Members of the Sphaeridiinae on the other hand are generally terrestrial species, inhabiting various types of organic matter including dung and compost or even rotting seaweed. The four Sphaeridium scavengers are all associated with dung.

Sphaeridium scarabaeoides is a relatively common and widespread dung beetle although, from the latest distribution map, is rarely recorded from the south-west. The typical habitat is grazing pasture preferably where there is cattle dung as that's the normal host material for the species, particularly when it's moist. Older horse and sheep dung may also attract adults. Mating pairs are common early in the season where they may be seen on top or within dung. The eggs are laid inside where the larvae will predate other insects, especially Diptera eggs and their larvae. New generation adults normally appear early June. They are strong fliers and are often the first species to arrive at fresh dung.

They measure around 5-7mm and are broadly oval in shape with a smooth convex body form. Their colour is variable, but the head and pronotum are mainly uniformly black, sometimes paler around the pronotal margin. The elytra are well-marked typically with paired dark red blotches at the front and pale yellowish-brown markings in the rear third. The legs are pale. Their distinctive markings make them one of the easiest hydrophilids to identify, which certainly isn't the case with the majority of species in this family.

New family added, July 22 (v.1)