Eledona agricola (Herbst, 1783)
This is a locally common species throughout Europe except for the far north, extending east to Asia Minor and Russia and south to northwest Africa; here it is generally common across Wales and England north to south Yorkshire though absent from the islands. Adults occur year-round; during the winter among wood or bark near to the host and otherwise almost always associated with the fungus Laetiporus sulphureus (Bull.) Murrill although during warm periods, especially in the spring and autumn, they disperse by flight and are attracted to light. Adults are attracted to damaged host tissue and may quickly arrive in numbers, oviposition occurs among the fruiting body and larvae develop within the fleshy sporocarps, they occur among tissue in all stages of decay and even old and dry fruiting bodies may contain them but they usually pupate within drier parts. The life-cycle is completed within a single year and new-generation adults appear from the middle of summer. Typical habitats include open woodland and parkland where the host develops on a range of deciduous trees, typically oak and beech but it has also been recorded from a wide range of host trees, usually living mature specimens with areas of damaged bark. Adults feed on spores and hyphae and may often be seen close to the base, around the edges of the fungus, but as infection proceeds and they continue to be attracted to the fruiting body they may occur among the flesh in very large numbers and remain through the summer as the fungus decays, and even old pale and very damp fungi may host numbers of the beetles. Adults are nocturnal and easily seen as they crawl around beneath the fruiting body, by day they remain still, often embedded among the tube-like pores beneath the fungus, and are easily recorded by tapping the host over a tray. Adults will usually be found among numbers of other fungus beetles; in our local park often with Diaperis, Triplax and various Mycetophagus species but also many others, and because the bright-yellow host, commonly known as chicken-of-the-woods or sulphur polypore, is so very conspicuous they are very easily recorded.
Eledona agricola 1
Eledona agricola 2
Adults are small, 2-3mm, very convex, glabrous and dull brown or grey with paler margins to the pronotum. Once identified as a tenebrionid by the tarsal formula and the hidden antennal insertions the specific identity is straightforward as the habitus and strongly sculptured surfaces are distinctive. Head short and transverse with small, emarginate eyes and short, clubbed antennae, the surface is strongly microgranulate and indistinctly punctured. Antennae inserted laterally under an expanded clypeal edge, 11-segmented and distinctive; segments 5 to 8 transverse and asymmetric and segments 9-11 forming a distinct club. Terminal maxillary palpomere cylindrical. Pronotum transverse and very convex, laterally rounded in the male, in the female evenly narrowed from the base to the protruding anterior angles, lateral margins roughly denticulate, basal margin curved or indistinctly angled. Surface rough, strongly granulate and indistinctly punctured. Elytra elongate with square shoulders and a continuously-rounded apical margin, laterally finely denticulate, striae represented by rows of strong punctures which are surrounded by smaller punctures, interstices raised into complete longitudinal carinae. Legs short, the femora barely visible from above, tibiae gradually widened to truncate apices, with finely denticulate ridges and produced into a strong tooth (much longer in the female) at the external apical angle. Tarsi 5-5-4; basal segments short and transverse, apical segment long and strongly broadened towards the apex.