Drypta dentata (Rossi, 1790)
Fowler (1887) summarized the records for the south coast of England and stated ‘local but sometimes taken abundantly, it is found on clay banks at the roots of grass etc. and occurs at the coast or inland under vegetable refuse, moss etc.’ and so provides evidence that the species was formerly more widespread and common. The modern distribution extends from Lyme Regis in Dorset to the South Hampshire coast, including the Isle of Wight, East Sussex and East Kent. Joy (1932) states ‘England, South, very local’, in notes that may have been taken from Fowler etc. but, given that Joy was so active in terms of collecting and communicating, may also have been written from experience. Several records from the early 1900’s, one from South Hants in the 1960’s and a few from the Isle of Wight in the early 1980’s represent the only twentieth century records from Hampshire, in Dorset it was recorded from Lyme Regis and Charmouth into the 1940’s but has not been seen since. There are more modern records from Brownsea Island and from a west Dorset locality from the late 1980’s, these seem to be the only localities where it still occurs and it is now thought to be in decline. On the continent it is very widespread, often locally common in the south where it seems to be increasing in both range and abundance but further north much more local and sporadic, occurring from Portugal to Ukraine and central and southern Russia, the Middle east and North and tropical Africa. Typical habitats are vegetated freshwater margins, fens and floodplain forests but they are not uncommon in ruderal habitats; vineyards, damp grassland and pasture from lowlands to low mountain altitudes. In the UK it is found among patchy vegetation around freshwater seepages from soft rock cliffs on the south coast. Adults are active in late spring and early summer, they are diurnal and roam damp substrate and climb reed stems etc in search of prey and will take flight in warm weather. Mating occurs early in the season, on the continent adults have been observed mating in April, and larvae develop through the spring and summer, new generation adults eclose in late summer and autumn and overwinter in groups under debris, bark or in the soil.
Drypta dentata 1
Drypta dentata 2
Drypta dentata 3
Within the U.K. fauna it is very unlikely to be confused with any other species; the metallic blue body, pale appendages and elongate form are distinctive.
7-9mm. Body entirely bright metallic blue. Appendages, including mouthparts, labrum and clypeus, orange. Head smooth between large and dense punctures, without furrows or impressions but with a sharp lateral ridge from the inner margin of the eyes to the antennal insertions. Eyes prominent, protruding and almost hemispherical. Mandibles elongate and protruding forward, smooth internally and sharply pointed. Palps long and slender; terminal labial palpomere dilated towards the apex and the terminal maxillary palpomere long and pointed. Antennae entirely pubescent, first segment darkened apically and longer than the next three combined, second segment diminutive, the remainder elongate. Pronotum elongate, without side borders and constricted before the base, densely punctured, and finely pubescent and microsculptured (x40 but the strength of this varies and may be almost absent.), width slightly narrower than the head measured across the eyes, with a deep median furrow which may be almost complete. Scutellum densely punctured and pubescent. Elytra about twice the pronotal width and lacking a basal border, with sloping shoulders and widened towards apex, constricted subapically and obliquely truncate, each with nine complete striae and an abbreviated scutellar stria, all of which are strongly punctured. Interstices uneven, finely punctured and pubescent and very finely microsculptured. Fore tibiae with a deep antennal cleaner. Fourth tarsomere deeply bilobed on all legs, the fifth elongate. Claws smooth and lacking a basal tooth. Male basal pro-tarsal segments dilated.