Rhagonycha fulva (Scopoli, 1763)
Widely distributed and common throughout England and Wales although more local in the north and southern Scotland and with only a few records north of Ayr (Alexander). It is common throughout the Watford area in all habitats, with huge numbers occurring from late July to early September in Whippendell wood and along the Colne valley from Watford to Radlett, we mention these localities because the species occurs here in extraordinary numbers but realistically they will be found in numbers anywhere. During 2007 they were present in town centre gardens on Buddleah, Convolvulus, Tagetes and Geranium flowers, in fact most things in flower will attract them. In late August, which is when they seem to be most abundant, flowering umbels among or near untended grassland tend to be covered in them. Adults are first seen in early or mid July; first sighting in 2007 was 7th July, the last on 16th September.

This is a very distinctive species; the combination of large size, orange head and darkened elytral apices will identify it in the field. Until experience is gained a few should be viewed under the microscope as there are several cantharids, mostly occurring earlier in the season, for which it may casually be mistaken e.g. Cantharis rufa, C.figurata, C.livida and Rhagonycha translucida, the tarsal structure and claws will separate all Cantharis species, the elytral apices R.translucida

8-10mm. Antennae black with first segment and base of second usually, but not always, orange, inserted between front margin of eyes. Palpi black. Eyes round and prominent, temples rounded and gently narrowed to pronotum. Head orange (cf. R.lutea (Mull.)), shiny, finely punctate and pubescent (X20). Pronotum orange and shiny, puncturation and pubescence less dense than on head, quadrate although it may look elongate, use a measuring eyepiece to convince yourself of this. Shape variable but narrowed towards head, gently sinuate laterally and basally, side margin explanate in front of middle, front margin rounded and raised. Strongly convex either side of middle in basal half. Elytra covering abdomen, or at least wings, testaceous and shiny, without striae and with rather dense recumbent yellow pubescence. Femora and tibiae orange, tarsi black with third segment simple i.e. not bilobed (cf. Cantharis), claws divided apically. Elytra in female dilated a little behind middle.

Description from 6 Watford specimens at X20.

See ID Aids for a key to the family