Pseudocistela ceramboides (Linnaeus, 1758)
This is the only European member of the genus; it is widespread though very local and in general seems to be rare e.g. in Germany (etc.) it is regarded as endangered, the distribution extends from Spain north to the U.K. and Southern Scandinavia, south to Northern Italy, and east to Russia and Ukraine. There are 2 colour forms, formerly thought to be distinct subspecies; P. c. ceramboides s.str. is widespread while P. c. serrata (Chevrolat, 1844) is more eastern, occurring in Hungary, Czech and Slovak Republics, and Greece. In the U.K. it is a local species of central southern England extending north to South Yorkshire. The species is saproxylic occurring in open deciduous woodland, wooded pasture and parkland etc. where there are large trees in various stages of decay, both adults and larvae have been recorded from a range of broadleaf trees but they show a strong preference for oak. Adults occur from May to July and are mostly crepuscular and nocturnal; they may be seen on the surface of standing and fallen timber, or they may be dug out from accumulated wood debris in hollows etc., they disperse by flight and are attracted to light, occasionally they become active in warm sun when they may be seen on leaves or flowers, especially the umbels of various Apiaceae. The larvae develop among wood debris and detritus in hollows etc. where they feed upon fungal mycelia, they resemble elaterid larvae; being long and cylindrical with short legs, and are creamy-yellow with the head and the apical third of all the body segments darker. Pupation occurs among wood debris from February to May.
Among our U.K. fauna Pseudocistela might casually be mistaken for Lagria but the resemblance is only in terms of size and colour; in detail they differ widely, in the field most obviously in the form of the pronotum and the antennae, but as with all other European tenebrionds, Lagria lack the pectinate claws of the Alleculinae.
Pseudocistela tenebroides 1
Pseudocistela tenebroides 2
10-12mm. Elongate and broadly oval with weakly rounded elytral margins; entirely black but for the reddish brown elytra, also the pronotum in serrata, and the apices of the tarsi. The pronotum and elytra, and to a lesser extent the head, are clothed with dense golden-yellow pubescence. The head is quadrate or nearly so, densely punctured and distinctly microsculptured, with longitudinal grooves between the eyes and above the antennal insertions. The frontoclypeal groove is well-impressed and the clypeus weakly curved around the anterior margin. Eyes reniform; strongly transverse and very prominent, in males larger and closer together than in females. Terminal segment of the maxillary palps securiform. Antennae serrate from the fourth segment; segment 2 much shorter than 1 and 3; in males the antennae are longer, about ¾ the body length; in females they are about half the body length. The pronotum is transverse and strongly narrowed from acute posterior angles to a continuously rounded anterior margin, the basal margin is bisinuate and the lateral margins only weakly bordered, the surface finely and densely punctured and microsculptured, and often with an impression either side of the middle. The elytra completely cover the abdomen and are smoothly rounded apically, with finely punctured striae complete to the apex and short scutellary stria, and flat, densely microsculptured interstices. The ventral surface of the body is entirely shiny black. Legs long and slender; the femora only weakly broadened in front of the middle, and the tibiae very gradually expanded towards the apex with all margins virtually straight, each with a stout spine on the inner apical angle. Tarsi 5-5-4 without lobed segments. Claws long, weakly curved and strongly pectinate internally.