CALLI'DIUM, a genus of Coleopterous Insects belonging to the section Longicornea and family Cerambycidce. It has the following characters :—Body depressed, thorax wider than the head, rounded at the sides; antennae generally shorter than the body ; palpi rather short, the terminal joint thicker than the rest, and truncated at the apex. Legs short ; femora suddenly thickened towards the apex, especially in the males ; tibiae simple.
Caladium Bajulus is not an uncommon insect in this country. It lives during the larva state in fir-timber, and when it occurs plenti fully is exceedingly destructive. The perfect insect is about three quarters of an inch long, of a flattened elongate form, and dull black or pitch colour ; the thorax is pubescent and has two smooth glossy tubercles on the disc ; the elytra are furnished with a fascia (more or less distinct) of silvery-white hairs.
Instances have been recorded of these insects attacking the fir rafters of houses, to which they are of course exceedingly injurious, and we have known instances when the perfect insects, in order to effect their escape, have perforated the lead with which the house-top was covered.
In many of the deal palings in the neighbourhood of London, and elsewhere, numerous oval-shaped holes (about a quarter of an inch in diameter) may be observed ; these are formed by the perfect insect of this species of Caladium to effect their escape, having passed through the larva and pupa states within the wood.
Mr. Stephens in his ' Catalogue of British Insects,' enumerates thirteen species of this genus, but of these many have undoubtedly been imported in foreign timber.