Poophagus sisymbrii (Fabricius, 1776)
This is Western Palaearctic species is locally common in lowland areas from France to the Black Sea, to the south it extends into Northern Italy and Bulgaria, although it is otherwise absent from the Balkan Peninsula, and in the north to the UK, Denmark and a few southern provinces of Sweden and Finland though it is absent from some of the Baltic countries. It was first recorded from Canada in the 1960s and has now become established following accidental introductions from Europe. In the UK it is locally common throughout England and Wales and very local generally scarce in Scotland and Northern Ireland. Typical habitats are wet meadows, marshes and wetland margins, usually in unshaded situations by still or slow-moving water with patchy vegetation. Host plants include various species of Brassicaceae, especially Watercress (Nasturtium officinale Aiton), less often Marsh Yellow-Cress (Rorippa palustris (L.)) and Great Yellow-cress, and probably other members of these genera. Adults occur year-round; they overwinter among litter and moss etc. or inside reed stems and are active from March or April until September, peaking in abundance from April until June. Mating occurs in the spring after a period of feeding and oviposition lasts for several weeks from the beginning of April. Eggs are laid in groups low down in stems and females may enter the water to do so, they hatch after a week or two and larvae feed within stems, often together in small numbers, they generally mine low down and often in submerged stems but do not enter the roots. Pupation occurs in a chamber within the stem, usually at the end of a feeding mine. Larvae have been found from May until September but it is not known whether there is a second generation in the summer. Adults may be sampled by sweeping among suitable foliage, they may be seen on foliage in warm weather but otherwise tend to remain concealed under leaves or against stems, they usually occur in numbers and are often restricted to a particular areas of within large growths and so may require extensive sweeping.
Poophagus sisymbrii 1
2.4-3.5 mm. An elongate and rather narrow species with a small head and raised epimera that are distinctly visible in front of the shoulders, black, with extensive rounded pale grey scales to the body and appendages, most specimens have well defined dark areas, usually along the centre of the pronotum and on the elytra, typically one below the shoulders, one on the disc and one at the apex, but these may be joined and in the basal half form a wide U-shape. Head small, with convex eyes and diverging temples, distance between the eyes about the same as the rostral base, rostrum long, curved and near parallel sided. Antennae inserted about the centre of the rostrum, long and slender with the scape gradually and only weakly thickened from the middle, funiculus 7-segmented and club elongate and narrow. Pronotum quadrate, broadest behind the middle and constricted and almost parallel-sided before the apical margin, basal margin produced medially, surface roughly punctured and with a fine median furrow, apical margin simple (not doubled) and closely approximated to the head. Elytra broadest towards the base, with sloping shoulders and separately rounded apical margins, striae narrow, unpunctured and complete to the apex, interstices flat, finely punctured and roughened, in places with a transverse rugosity. Legs long and slender, femora unarmed, front tibiae rounded apically, middle and hind tibiae sharply produced at the apex, claws simple (not fused at the base). In the majority of cases this species is readily identified from general appearance, but important diagnostic characters are the slender form, simple pronotal apical margin, 7-segmented funiculus and unarmed femora.