Temnoscheila Westwood, 1830
This is a large genus of about 110 species with the vast majority occurring in Central and South America, 10 have been recorded from the U.S.A. and 3 are Palaearctic, of which 2 occur very locally in Europe and North Africa. Some have very restricted and isolated distributions e.g. T. japonica Reitter, 1875 from the Far East and Japan, while others are widespread e.g. the Central and South American species T. virescens (Fabricius, 1775) which has been introduced as a bio-control agent of scolytids in Australia. No species have been recorded in the U.K. but very typical, and serving to illustrate the genus as a whole, the type species T. caerulea (Olivier, 1790) is probably the most widely distributed of all, being generally common in conifer woods across Southern Europe, and with very localized and scattered records from Central Europe, North Africa, The Canary Islands and east through Asia to China and Japan. It has also been introduced as a biocontrol agent to other areas. All members are saproxylic and, while a few South American species are known to be fungivores, the majority are predators of other insects, particularly other saproxylic beetles, both as adults and larvae. The adults are mostly nocturnal, roaming the trunks and branches of trees and shrubs in search of prey, and in hot weather they may also be diurnal. They fly well and come to U.V. light, often in large numbers. Larvae live under bark but occasionally roam the surface to find prey. Adults are said to be able to inflict a painful bite; note the powerful mandibles!
They are medium sized beetles, 6-26mm and, at least to some extent, and often vividly, bright metallic blue or green. Characters distinguishing them among the family are the overall habitus, the deeply emarginate labrum, pronotal margins which are deflexed towards the base and, in the males only, a deep pit on the submentum. Females are often much larger than the males. To put the genus into some context among the trogossitidae see T. japonica which is suggestive of a large Tenebroides. And to see a truly splendid example of the family see T. splendid Gory, 1831 from Belize.