Cionus nigritarsis Reitter, 1904

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POLYPHAGA Emery, 1886

CURCULIONOIDEA Latreille, 1802

CURCULIONIDAE Latreille, 1802

CURCULIONINAE Latreille, 1802

CIONINI Schönherr, 1825

Cionus Clairville, 1798

Widespread in Europe from the Pyrenees to the Balkan Peninsula and north into the UK and southern provinces of Norway, Sweden and Finland, also recorded from Turkey and said to be widespread in western Asia, this species is locally common in southern and central regions but much more local and scarce in the north. There is some evidence to suggest a recent expansion of the range e.g. it was first reported from The Netherlands in 1998 and from Lithuania in 2010, although this may be due to past confusion with closely similar species. In the UK it is very local and scarce across Southern and Central England with the exception of the West Country and there are a few scattered records from Wales. Typical habitats are open and dry grassland and pasture, especially on hillsides exposed to the sun, road verges, woodland clearings and ruderal sites where the host plants are common. The species is polyphagous on various Scrophulariaceae; in the UK often on Black mullein (Verbascum nigrum L.) and less so on Greater mullein (V. thaspus L.), but more generally also on White mullein (V. lychnitis L.) and Common figwort (Scrophularia nodosa L.). Adults are active from May until August although specimens occasionally occur much later, into November, and these are presumably new-generation adults that become active before overwintering. Mating occurs early in the season and females oviposit near the tips of young shoots or in flowers. The pale brown or yellowish and slug-like larvae feed exposed on leaves or in flowers and when mature they spin an oval silken cocoon in which to pupate, this is usually exposed on a narrow stem or may be among flowers or on leaves. Adults emerge in the summer and may become active on the host plant for a while or they may fly to find further host material before overwintering. Adults can be found by beating host plants; they usually occur higher up on larger plants and where the plants are common they may occur in numbers on only a few plants.

Cionus nigritarsis 1

Cionus nigritarsis 1

Cionus nigritarsis 2

Cionus nigritarsis 2

Cionus nigritarsis 3

Cionus nigritarsis 3

3.6-4.3mm. Very typical of the genus with a narrow forebody and broad, distinctively patterned elytra. Overall colour pale creamy-grey; the even numbered elytral interstices with uniform elongate grey scales, antennae pale with the club dark, legs dark with (contrary to the specific name) reddish tarsi. Head narrow between large and convex eyes that occupy most of the outline, with scattered pale scales which usually do not extend onto the rostrum. Rostrum long, curved and slightly expanded about the antennal insertions, in side view of more or less constant width to a rounded apex, not sabulate. Antennal scape gradually expanded in the apical half, funiculus 5-segmented and club narrow and pointed. Pronotum transverse, broadest across obtuse posterior angles and unevenly converging to a narrow apical margin, surface evenly convex, finely punctured and with rather dense elongate pale scales. Scutellum elongate, triangular and with pale scales as the surrounding elytra. Elytra quadrate and smoothly curved from broadly-rounded shoulders to a continuous apical margin, striae strongly punctured and complete to the apex, interstices flat and finely punctured, even numbered interstices with grey scales, odd-numbered interstices chequered black and pale grey, with a round or elliptical black spot towards the middle and another, usually distinctly smaller spot before the apex. The form of the first and second striae is important; they both deviate gradually around the discal black spot and remain well separated before straightening beyond the disc, in the closely similar C. longicollis the inner stria curves more strongly than the second so that they almost make contact outside the middle of the spot. Legs long and robust, femora toothed ventrally, tibiae without obvious apical spurs. Tarsi pseudotetramerous with the third segment strongly bilobed and the fourth diminutive. Claws fused at the base, without a basal tooth and unequal in length, especially in males.