Dacne bipustulata (Thunberg, 1781)







POLYPHAGA Emery, 1886

CUCUJOIDEA Latreille, 1802

EROTYLIDAE Latreille, 1802

EROTYLINAE Latreille, 1802

DACNINI Gistel, 1848

DACNE Latreille, 1796

This is the most widespread and common member of the genus, it occurs throughout Europe from the Mediterranean to the northern provinces of Fennoscandia and extends east into Siberia, it is generally common throughout England and Wales though mostly absent from the West Country and local and sporadic in the north. Adults occur year-round; they pass the winter under bark or among debris in hollows etc. and become active from early spring when they may be found in association with various fungi, they are nocturnal and gregarious and often occur among numbers of other saproxylic fungivores. They may occur in any habitat where old trees at various stages of decay are present, including domestic gardens and roadsides; they occur on a wide range of Broadleaf species and also, though less commonly, on conifers.  Searching at night during the warmer months is the best way to find them, they almost always occur close to or on the surface of fungi or among bark previously hosting fruiting bodies, most often on softer species such as Piptoporus betulinus (Bull.) P. Karst., Laetiporus sulphureus (Bull.) Murrill or Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm. but they have been recorded from a wide range of species as follows: larvae and adults from Daedalopsis spp., Fistulina hepatica (Schaeff.) With., Ionotus hispidus (Bull.) P. Karst., I. radiatus (Sowerby) P. Karst., Polyporus squamosus (Huds.) Quélet, and Trametes cervina (Schwein.:Fr) Bres. And adults might be found on a wider range of fungi.

Dacne bipustulata 1

Dacne bipustulata 1

Dacne bipustulata 2

Dacne bipustulata 2

Dacne bipustulata 3

Dacne bipustulata 3

2.5-3.3mm. Very distinctive among our fauna by the overall appearance and abrupt antennal club, it is most likely to be confused with D. rufifrons, with which it is often found, but this species has the pronotum extensively dark with a distinctly narrower explanate margin, specimens with the pronotum pale have the surface microsculptured and rather dull. Head and pronotum pale, the pronotum often darker along the base, elytra dark with a pale sub-humeral macula. Head evenly convex and finely punctured, with relatively large but weakly-convex eyes and antennae inserted laterally and widely separated. Basal two antennomeres elongate, 3-8 quadrate or transverse and 9-11 widely transverse, forming an abrupt and slightly elongate club. Pronotum transverse and widest about the middle, lateral margin explanate, about as broad as the width of the second antennomere, anterior margin rounded and produced, posterior margin strongly sinuate and produced medially, surface moderately strongly punctured, on the disc the punctures are mostly separated by more than their diameters. Scutellum transverse, dilated from a straight basal margin and rounded apically. Elytra with a sharp humeral angle then smoothly curved to a continuously rounded apex, usually impressed inside the shoulders but without distinct striae; there may be continuous lines of punctures on the disc but otherwise randomly and finely punctured, usually much finer or evanescent towards the apex. Legs entirely red; femora only narrowly visible from above, tibiae expanded from the base to an obliquely-truncate apex, the apices with a row of pale setae around the inner margin and without distinct spurs. Tarsi with short, quadrate or weakly transverse basal segments and a long and weakly expanded apical segment, claws short and weakly-curved, without a basal tooth.