POLYPHAGA Emery, 1886
DASCILLOIDEA Guérin-Méneville, 1843
Dascillus Latreille, 1796
D. cervinus (Linnaeus, 1758)
DASCILLIDAE Guérin-Méneville, 1843 (1834)
Our single UK species is distinctive and generally common, and should be found when working grassland during the summer months.
Around the World
This family was formerly much more broadly defined and included many species now classified in the families Ptilodactylidae, Psephenidae, Artematopodidae and Scirtidae, and as such it included around 200 species. The Dascillidae now includes around 80 species in at least 15 genera divided among 2 subfamilies. The Dascillinae s.str. are Holarctic as well as Australian but are apparently absent from Africa and South America. Of the 23 or so species of Dascillus Latrielle, 1796 only one is widespread in Europe including the U.K. 5 species of 2 genera occur in North America. The Karumiinae Escalera, 1913 includes at least 5 genera, occurring in North and South America, North and Central Africa and Eurasia; no species of this subfamily occur in Europe. The largest species diversity of the family as a whole occurs in Asia.
The majority of species are medium sized, 4-26mm, and rather soft bodied. Generally elongate or elongate-oval and moderately flattened to convex with the lateral margins unevenly curved. The upper surface varies from glabrous to densely clothed with hairs, setae or scales. Most species are drab; grey or brown, sometimes black, and in some the dorsal surface is patterned by pubescence. The antennae are 11-segmented and not clubbed; usually filiform but sometimes serrate. In most species there is a sclerotized labrum is present and there is a well developed scutellum. The hind wings are well developed and most species are good fliers.
Adults occur on vegetation, especially on grassland in marginal habitats, from late spring and persist well into the summer. Larvae of Dascillus and Notodascillus Carter, 1935 are subterranean, feeding on roots, especially of grasses. Larvae of at least some members of the family feed on subterranean termites.
Dascillus cervinus (Linnaeus, 1758)
This is the only member of the family to occur in central and northern Europe. In the U.K. it is widespread but local throughout England and Wales including the Isle of Wight and Anglesey but not Man, and there are several records from the Scottish Highlands and one from Skye. On the continent they occur in wetland areas; wet meadows and peat bogs etc. in upland areas. In the U.K. they are found in a range of habitats, generally among vegetation but especially grassland near wooded borders and streams etc. They are often abundant on calcareous grassland where the adults are easily seen in flight during hot weather; in the South Buckinghamshire Chilterns they are common on south facing hillsides where we have found masses of adults drowned in cattle troughs. On one occasion we observed abundant adults on the flowers of Leucanthemum vulgare Lam on chalk grassland. Adults appear from May to early or mid summer and are generally abundant by mid June. Larvae live in the soil feeding upon roots, generally those of grasses; final stage larvae occur throughout the year but especially in the autumn and winter while pupae have been found in the spring and early summer.
The Orchid Beetle is readily identified, even in the field, by the large size, 8-12mm, the elongate oval form and densely pubescent dorsal surface. The widely bilobed tarsal segments are usually obvious. Colour ranges from dark grey to pale grey or brown. Gravid females are obvious. Head finely but deeply punctured, densely pubescent and with a transverse impression between the antennal insertions. Eyes convex with the front margin weakly sinuate. Labrum small and transverse. Mandibles stout and prominent. Antennal segments densely pubescent. Pronotum finely and densely punctured; broadest before obtuse hind angles. Hind margin not bordered, sinuate either side of a broad and prominent scutellum. Elytral margins explanate, becoming broader towards the apex, hidden towards the base by the humeral convexity. Striae weakly impressed and punctured, interstices convex, generally obvious from the pubescence. Fully winged. Legs robust; tibiae sinuate, each with two strong spurs on the apical margin. Tarsi 5-5-5; 1-4 bilobed, 4 deeply so, 5 elongate. Claws robust and weakly toothed at the base. According to Joy (1932) the male is narrower, entirely black or pitchy, the female broader, entirely reddish yellow, rarely black.