Heteroceridae
Small beetles associated with wetland or coastal mud flats and salt marshes. They live in colonies near the water's edge or high tide mark where more than one species may be present. For the most part they live below the surface of waterlogged fine silty soil where a male and female will occupy a gallery. With experience one may recognise the tracks of raised soil they leave when constructing the galleries. Adults are active from early April, depending on season, when they may be found on damp soil at considerable distance from water; on April 11th 2007 we found many Heterocerous fenestratus on Common moor some 200m. from the river in company with many carabids e.g. Elaphrus, Bembidion etc. the Heterocerous were active on damp ground in hot sunshine. During June, July and August we have attracted these to M.V. light in whippendell wood at least 500m. from water. Eggs are laid in spring and larvae live in the adult galleries, they pupate deep in the soil and adults emerge during the summer. It is thought both adults and larvae feed on organic detritus in the soil. Several of our species are common.     2.5-3mm. Head large with protruding mandibles and labrum. Antennae short with elongate club. Pronotum transverse, as broad as, or nearly so, as elytra. Elytra entire, covering abdomen and sometimes distinctly patterned. Elytral pattern can be a good diagnostic character but care must be taken as immature specimens lack pigment. Legs of medium length, tibiae broad, fossorial with strong spines on outer edges. Tarsi unmodified, 4-4-4 with long curved claws. Entire body with dense pubescence of different lengths forming layers which provide a stronglly hydrophobic covering, this is easily appreciated at X20. There is much overlap in morphology and it is often necessary to examine the genitalia for a certain ID. The very comprehensive RES handbook by R.O.S Clarke should be consulted.     Once familiar these are not likely to be confused with any other group, however, when sieving riparian mud each specimen should be examined carefully with a lens as, especially when the sieve or tray contains organic matter, Dryops might be overlooked for these.
Heterocerus fenestratus	Heterocerus fenestratus	Heterocerus fenestratus	Heterocerus fenestratus	Heterocerus fenestratus