|Graptodytes flavipes (Olivier, 1795) RDB 2 - Vulnerable|
's statement that 'Hydropens flavipes is definitely southern in Britain' is supported by the distribution of
modern (post 1990) records on the latest (July 09) NBN map; s.w. Cornwall, s.e. Dorset and s.Hants but there is also
a single isolated record above Inverness! Formerly more widespread in the south; there are older records from
Pembrokeshire (coastal), Cambridgeshire (Burwell fen, 1910), East Sussex and the home counties; Fowler notes that
'it appears to be chiefly found in the London district (Weybridge, Esher, Reigate, Chobham, Gravesend etc)' and he
also quotes a record from Anglesey (sic).Friday gives
the typical habitat as heath ponds, as does Fowler while Joy
's broader statement 'ponds in heathy districts' well describes the site of our only encounter with the species; a
stagnant and weed choked pond near Brockenhurst, s.Hants during June 2009. Here we found the adults in abundance
among other small dytiscids eg Hydroporus pubescens and H.planus. Balfour-Browne quotes the species as
very local but abundant in certain parts of Dorset and the New Forest and so our record is perhaps not surprising.
Finding the species in Watford might well be surprising but we have featured it because, although small, it is
strikingly coloured, readily identified and, in any case, just plain fascinating.
2.5-2.8mm (our specimens) Elongate oval and rather narrow. Head shiny black with front margin of clypeus and labrum testaceous, puncturation fine and sparse, microsculpture very fine, just visible at X40. Clypeus with a shallow, more or less triangular impression inside front margin of each eye. Eyes convex; bulging a little from the outline of the head, front margin emarginate. Antennae piceous with thre or four basal segments testaceous. Pronotom black with testaceous lateral margins, microsculptured as head, puncturation fine and sparse on disc, dense and coarse behind front margin. With a short sublateral (roughly at the inner margin of the testaceous colouration) longitudinal furrow which does not reach the front or rear margins. Lateral border very fine, front angles protruding, hind angles obtuse. Scutellum not visible; hind margin of pronotum produced back medially. Elytra black or piceous with five longitudinal testaceous marks, the marginal mark entire from shoulder to apex. The innermost three may be fused across the base or the innermost discrete and the next two fused. Fourth fused with fifth at base. Outermost may have transverse extensions before apex and all may be interrupted by the black ground colour. Microsculpture finer than on pronotum, puncturation fine and sparse. Base smooth; without impressed longitudinal lines. Legs yellow. Pro and metatarsi four segmented; segments 1-3 broad, more so in male, 3 deeply bilobed, 4 proportionally very long. Protarsal claws in female equal, or nearly so, in length, im the male the inner claw is a little broader and shorter.
Description from 2 south Hampshire specimens at X40