Nedyus quadrimaculatus (Linnaeus,1758)
A common and usually abundant species widely distributed throughout the British isles north to Shetland (Morris, 2008). Nedyus is common across our Watford area, the adults are generally associated with nettles and are active from the first warm days of spring, they soon become abundant and adventitious among low and dense herbaceous growth in just about any situation. We have recorded them from town centre gardens, wasteland and parkland and even from nettles growing as weeds in alleyways and municipal shrub beds, the habitat seems unimportant so long as the host is present; shaded bankside nettles overhanging the river Colne along Radlett road produced adults in numbers when swept. Joy lists the species simply as very common while earlier Fowler (Vol5) regarded it as our most abundant weevil. Adults remain abundant through May and June and into July, exceptionally occasional specimens occur in August. We have also recorded adults in late September. Larvae develop in the roots of nettles (Davis, 1983)

This small dark and very convex weevil may often be rocognised by the presence of two prominent patches of pale scales on the elytra although these may be absent and the extent of pale scaling in general varies. Completely dark specimens are common. With some experience of looking at nettle weevils under a hand lens Nedyus in all its forms will become obvious. When alarmed they draw in the appendages and remain still so resembling seeds or debris in the sweep net, after a minute or two they begin to start crawling.

2.2-3.5mm (Joy) 2.6-3.2mm (Morris). Form broadly oval and convex, cuticle black and shiny. Head coarsely and densely punctured, variously clothed with pale elongate and oval scales. Eyes convex and oblique to sides of rostrum, temples widened to base. Rostrum long and curved, punctate throughout, antennal insertions near or a little beyond middle. Antennae red with club dark. Scape short and gradually thickened beyond middle, funiculus seven segmented, club shorter than funiculus, thick and pointed. Pronotum deeply impressed behind slightly raised and smooth front margin, disc convex with a pointed tubercle either side and deeply impressed in front of strongly bordered posterior margin. Surface strongly and densely punctured and variously scaled, sides usually with dense pale and oval scales. Elytra quadrate, broadest at shoulders where the seventh interstice is raised, base raised to a strong border to either side of scutellum which is usually not visible. Interstices a little broader than the deeply impressed striae, coarsely punctate and variously scaled; often with a patch of white scales across middle of interstices six and seven and across apex of inner interstices. Without tubercles or with a few only weakly developed at apex. Femora black, middle and hind femora toothed beneath, front femora without or with weakly developed tooth. Tibiae and tarsi lighter, usually reddish. Each tarsus with two distinct claws. Seen from beneath the rostral channel extends to just beyond hind margin of the mid coxae.

Description from 12 Watford specimens at X20

Reference
Davis, B.N.K. 1983. Insects on Nettles. Naturalists Handbooks,1. Cambridge University Press.


Rostral Groove

Rostral Groove

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