Deliphrum tectum (Paykull, 1789)
This is a mostly Western and Central European species; it is generally common from the Pyrenees to Hungary and Serbia in the south and to the UK and the far north of Fennoscandia in the north, further east it is widespread in Siberia and occurs in the far east of Russia, this distribution seems to be discontinuous although it may be under-recorded or spreading as it was first recorded from Kazakhstan in 1999. Throughout the European range it occurs from lowlands to lower mountain altitudes, reaching 2400 m in the Alps. In the UK it is widespread though very local in Central and Northern England and there a few records from Wales and Southern Scotland. Adults occur from March until November, peaking in abundance during April and, especially, May, they have occasionally been recorded earlier in the year but it is not known whether they overwinter. They sometimes occur among dung or decaying vegetation and straw etc. on grassland and arable land but more typical habitats are open deciduous, mixed and conifer woodland and wooded parkland where they occur among accumulated litter and under loose bark, they have been recorded from dung in such habitats and during warm spring and summer evenings they occur at sap, especially on oak (Quercus L.), beech (Fagus L.) and birch (Betula L.). More generally they occur at decaying fungi, especially where these are damp and host numerous early stages of other insects, and any sample in a suitable state of decay may host them, on the continent they have been recorded from Northern Honey Fungus (Armillaria borealis Marxm. & Korhonen), Crepidotus calolepis (Fr.) P.Karst, Pale Oyster Fungus (Pleurotus pulmonarius (Fr.) Quél.) and Hen of the Woods (Grifolia frondosa (Dicks.) Grey. Adults are mostly nocturnal and so searching fungi or sap by night or taking samples of likely material for extraction during the spring is the best way to find adult beetles as numbers decline from June and they remain low throughout the season.
Deliphrum tectum 1
Deliphrum tectum 2
3.0-4.0 mm. A very distinctive species that may be recognized in the field by the general shape and colour; broadly-oval, rather flat and discontinuous in outline, head black, pronotum black with wide lateral and narrow basal and apical yellow borders, elytra brownish-yellow, abdomen extensively dark, legs pale, antennae dark with three or four basal segments paler. Head transverse with convex and prominent eyes and short and strongly converging temples, vertex transversely impressed between two ocelli that are usually pale and contrast with the darker cuticle, and with two longitudinal impressions that extend onto the clypeus, frons strongly narrowed and rounded anteriorly, entire surface finely but not densely punctured. Antennae inserted laterally in front of the eyes, 11-segmented and very weakly broadened from the middle, three basal segments distinctly elongate; the first about as long as the next two combined. Terminal maxillary palpomere long and pointed, about as wide as but much longer than the penultimate segment. Pronotum transverse, widest behind the middle and smoothly curved to rounded angles, anterior margin distinctly narrower than the basal margin and almost straight. Pronotal surface weakly convex, without structure but for a variable but usually weak median dimple in front of the basal margin, and finely punctured throughout. Elytra quadrate to slightly elongate (measure along the suture) and dilated from rounded shoulders to an almost straight apical margin, lateral margins narrowly explanate, almost grooved, so that they appear doubled towards the apex, surface without striae, with dense and rather strong punctures that form oblique rows in places. Abdomen rounded and strongly tapering, tergites with wide and weakly-raised lateral borders and finely punctured and microsculptured throughout. Legs long and slender with femora only narrowly visible in normal setting. All tibiae with fine spines along the external margin and a very fine terminal spur. Tarsi –segmented, claws smooth and with a weak obtuse tooth at the base.