Cartodere bifasciata (Reitter, 1877)
Native to Australia, this species was first introduced into Europe with tobacco imported into Germany in the late nineteenth century and it soon spread in the wild; it is now locally common across western and northern Europe from Portugal to Denmark and southern Sweden, and sporadic but regularly recorded south to the Mediterranean, this range is still increasing e.g. there are modern records from northern Italy and Turkey, and it is likely to spread throughout the region. Although not a major pest species, it is associated with a wide range of stored foodstuffs and has been reported from many countries worldwide, this has probably increased over recent decades e.g. it was first recorded from the Nearctic region in 1989 and has since become established in the United States and Canada, and it is likely to become established worldwide. In the UK it is generally common throughout England and Wales, although more local in the West Country and the north, and sporadic and rare further north into southern Scotland. Adults occur year-round and are active in the wild over a long season from early spring although they might occur inside at any time, they may be found in among soil and leaf-litter, decaying bark and organic material such as hay, straw and fungi in a wide range of habitats from woodland to wooded parkland and grassland etc, although they generally prefer more open habitats, and they often occur in numbers. Breeding is thought to occur through the spring and summer, larvae develop among decaying organic material in the summer, and both adults and larvae are known to feed on moulds and spores. Adults are readily sampled by sieving organic matter, but they are mainly nocturnal and can be found by searching under bark or on the surface of dead wood at night, they can be often be found in numbers on recently-cut trunks and branches which are still exuding sap, they sometimes visit sap from bark wounds on healthy trees, often appear on fire-damaged trunks, and can be lured to fermenting fruit traps. Under artificial conditions they have been found breeding among a wide range of stored products including various grains, malted barley, grass seeds, raisins, tobacco and wheat flour in both heated and unheated storage systems.
Cartodere bifasciata 1
Cartodere bifasciata 2
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.htm
A small, around 2mm, and very distinctive species owing to the dorsal sculpture and colouration, typically the dorsal surface is shiny brown with the forebody paler than the elytra, the pronotum is variably darkened and the elytra have dark markings; maculae in the basal third and laterally, and a transverse band towards the apex, but these vary and may be fused or greatly expanded so the elytra appear substantially dark, legs pale brown and antennae brown with the club darker. Head with convex and moderately large eyes and long, curved temples, surface flat, irregularly impressed and roughened, antennae inserted laterally on long, converging cheeks, basal segment much broader than the second, 3-8 long and narrow and 9-11 forming an elongate club. Pronotum quadrate, with straight apical and basal margins, lateral margins more-or-less straight and strongly constricted about the basal third, the surface rough, irregular and strongly impressed across the basal third. Elytra with rounded shoulders and evenly curved to a continuous apical margin, the lateral margin usually sinuate in the basal half due to strong impression along the declivity, striae strongly impressed and punctured, interstices convex; often more strongly so towards the base and over the apical declivity but never carinate. Legs long and slender; femora smooth, tibiae smooth and without obvious apical spurs. Tarsi without lobed segments. Very dark specimens might be mistaken for C. nodifer but here the elytra are much more strongly sculptured than those of the present species.