Pria dulcamarae (Scopoli, 1763)
POLYPHAGA Emery, 1886
CUCUJOIDEA Latreille, 1802
MELIGETHINAE Thomson, C.G., 1859
Pria Stephens, 1830
Pria Stephens, 1829 is a widespread Old World genus of about species, the vast majority occur in tropical Africa and only a very few are known from Australasia and the Palaearctic region. Three species occur in Europe but two of these have restricted distributions; P. zenobia Jelinek, 1997 is known from Greece, Turkey and Israel, and P. transitoria Kirejtshuk, 1979 from the Caucasus and southern Russia. P. dulcamarae is a widespread Palaearctic species, it occurs throughout Europe north to the UK and southern provinces of Scandinavia, south to Asia Minor, North Africa, the Canary Islands and Madeira, and extends through Russia into Mongolia and Siberia. In the UK it is locally common in south east England, East Anglia and the midlands but otherwise very local further north to Yorkshire, it is generally absent from the west but occurs in a few coastal locations in Wales and the West Country. Adults occur year-round, they overwinter in the soil or among tussocks or litter and are active over a long season from early April until October, peaking in abundance during August, although they may be absent for a while before the new generation appears. Host plants are Bittersweet (Solanum dulcamarae L.) and, to a lesser extent, Black Nightshade (Solanum nigrum L.) , and typical habitats for the beetles are wherever these grow in abundance, often in marginal wetland situations but also damp woodland and grassland, hedgerows and agricultural borders but also in disturbed habitats such as gardens and allotments. Adults feed on host foliage and flowers, they fly well and also visit a range of other flowers to feed on pollen, these are often yellow flowers such as Dandelion (Taraxacum officinale F.H. Wigg.) or Hawkweed (Pilosella caespitose (Dumort) but they are sometimes common on hawthorn blossom and other flowers. Mating occurs after a period of feeding in the spring and females lay groups of eggs in unopened flower buds. Larvae begin feeding before the buds open and will complete their development in the opened flowers, feeding on pollen and, probably, flower parts as well, they become fully grown by early summer and drop to the soil to pupate in a cell below the surface. New generation adults occur from June and will feed on flowers and pollen through the summer before they overwinter. Adults may be sampled by sweeping host plants but they disperse by flight and may sometimes occur on other flowers some distance from the host, and later in the year they have been found in the afternoon and evening swarming in flight around host plants in flower.
Pria dulcamarae 1
Pria dulcamarae 2
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.htm
Pria dulcamarae 3
© U.Schmidt https://www.kaefer-der-welt.de/index.htm
1.6-2.1 mm. Elongate-oval and discontinuous in outline, pale to dark brown, often with the base of the pronotum and elytra darker, sometimes extensively so, legs paler, antennae pale and gradually darkening towards the apex, the club sometimes black. Entire dorsal surface finely punctured (this may be indistinct in places) and pubescent and with very fine cellular microsculpture. Head widely triangular from above, with prominent convex eyes and very short temples, cheeks long and strongly converging to a narrow and truncate apical margin. Palps with all segments long and narrow, antennae inserted laterally above the base of the mandibles, 11-segmented and loosely clubbed. Pronotum transverse, broadest behind about the middle and smoothly narrowed to a weakly-curved apical margin, and much more weakly narrowed to almost perpendicular posterior angles, basal margin weakly sinuate and unbordered. Surface weakly convex, rather flattened, and evenly explanate laterally. Scutellum large and triangular, rounded apically and densely and very finely punctured throughout. Elytra with sharp, slightly obtuse humeral angles and smoothly curved and narrowed to separately-rounded apical margins which leave the pygidium exposed, without striae but a variously-developed and sometimes faint or incomplete impression beside the suture. Last visible sternite smooth, without curved impressed lines. Legs short and robust, anterior tibiae finely toothed externally. Tarsi 5-segmented, basal segments bilobed, terminal segment long and slender. Claws smooth and weakly toothed at the base. Males with a 4-segmented antennal club, female club with 3-segments.