BOLETO'BIUS, a genus of Coleopterous insects of the section Brachelytra (M'Leay), and family Tachyporidce (Staphylinus of older authors.) Generic Characters :—Head long and pointed anteriorly; antennae with the basal joiut rather long and slender; the three next joints slender, and nearly of equal length, the remaining joints gradually increasing in width to the last, inclusive ; palpi rather long and slender ; thorax narrower before than behind, the hinder angles rounded ; elytra smooth, or indistinctly striated ; body long, widest at the base, and tapering to a point at the apex ; legs.moderate, tibias spinose, the four posterior with long spines at their apices.
The species of this genus reside in Boleti and other species of Fungi, in which they occur in the greatest abundance, particularly when in a state of decay. They are all exceedingly active, and their smooth slender bodies and pointed heads render it an easy task for them to thread their way with rapidity through the putrescent Fungi.
B. lunatus (Linn sus) is one of the most beautiful and largest species of the genus, and is not uncommon. It is about a quarter of an inch long. The head is black ; the antenme have the three board joints yellow, the remaining black, with the exception of the terminal joint, which is yellow ; the thorax and legs are yellow ; the wing-cases are of a blue-black colour, with an oblique yellow spot on the shoulders; the body is yellow, with the apex black.
About eighteen species of this genus have been found in this country, almost all of which are varied with yellow and black. Many have the wing-cases yellow, with two black spots, one on each side of the apex ; some have also the region of the acutellum black.
(Stephens, Illustrations of British Entomology.)