Kateretes pusillus (Thunberg, 1794)

Female
A local species found throughout England to southwest Scotland ( Kirk-Spriggs). Usually associated with wetland habitats where adults may be found on various sedges (Carex spp. Fowler records it from C.pomiculata). Adults first appear locally in early April when they are active on warm days seeking out and often congregating on whatever flowers are available, just about anything in flower will attract them so we have not (yet) bothered to record the flora . At this time they are adventitious although admittedly never far from water; during April 2007 they were common on all sorts of vegetation throughout the wooded, and often shaded, western borders of Cassiobury park, sweeping 10 metre samples during overcast weather produced dozens of specimens. By May they can be swept from all kinds of wetland vegetation including emergent aquatic vegetation on open water, they seem to show no preference, as many will be found sweeping randomly as from Carex. From April they are common around wetland throughout our area, the western (wet) half of Common moor, wher Carex is common, hosts large populations. Most abundant in the spring, we have recorded them until late July when completely testaceous specimens occur (Freshly emerged ?).
1.6-3mm. The form of the basal antennal segments will identify this species; First segment elongate and dilated, more so in male, second segment less so but still much larger compared with third, 9-11 form an abrupt and loose club. Head triangular, eyes and mandibles prominent, clypeus with a weakly sinuate transverse impression behind antennal insertions. Pronotum transverse, bordered and finely crenulate laterally, in our series more pronounced in male. Front margin not bordered, hind margin very finely so, hind angles either rounded or with only a very indistinct angle. Scutellum large, equilateral. Elytra quadrate or slightly elongate, truncate with hind margin smoothly rounded leaving last two abdominal sternite exposed. Colour varies from completely testaceous (immature?) to black with a well defined testaceous macula on disc, more usually testaceous and darker around margins and behind scutellum. First visible abdominal sternite produced posteriorly at hind angles. Head, thorax and abdomen vary from testaceous to black. Entire upper surface with fine pale recumbent pubescence. Head, thorax, scutellum and elytra with large punctures. Puncturation on abdomen much finer. Eltra are more shining due to lack of microsculpture which is obvious on head thorax and scutellum. Appendages pale. Tibiae broadened towards apex which is obliquely truncate, each with two small terminal spines. Tarsal segments 1-3 bilobed, claws without basal teeth.

Fowler, 1885 The Nitidulidae of Great Britain. Ent.Mon.Mag. 21:57.
Bagnall records the species from Cherry blossom in May. Transactions of the Nat.Hist.Soc. of Northumberland, Durham and Newcastle-0n-Tyne 1:224-247.
Bagnall records the species in the autumn. Ent.Mon.Mag. 41:162-163.

Description from 10 Watford specimens at X40


Male

Female

Male

Female

Male