Fig. 125—Apate capucina. Europe. A, Larva (after Perris); B, perfect Insect.
Fam. 53. Ptinidae.—Tarsi five-jointed, first joint not reduced in size, often longer than second; front and middle coxae small, not transversely extended, the former slightly prominent; five visible ventral segments; prosternum very short. Here are included two sub-families, Ptinides and Anobiides; they are considered as distinct families by many authors, but in the present imperfect state of knowledge[[124]] it is not necessary to treat them separately.
Fig. 126—"Biscuit-weevil." Anobium paniceum.
Fig. 127.—Early stages of Anobium paniceum. A, Eggs, variable in form; B, larva; C, pupa; D, asymmetrical processes terminating body of pupa. [This larva is probably the "book-worm" of librarians].
Ptinidae are sometimes very destructive to dried animal matter, and attack specimens in museums; Anobiides bore into wood, and apparently emerge as perfect Insects only for a very brief period; Anobium (Sitodrepa) paniceum is, however, by no means restricted in its tastes; it must possess extraordinary powers of digestion, as we have known it to pass several consecutive generations on a diet of opium; it has also been reported to thrive on tablets of dried compressed meat; in India it is said to disintegrate books; a more usual food of the Insect is, however, hard biscuits; weevilly biscuits are known to every sailor, and the so-called "weevil" is usually the larva of A. paniceum (Fig. 127, B). In the case of this Insect we have not detected more than one spiracle (situate on the first thoracic segment); the other known larvae of Anobiides are said to possess eight abdominal spiracles. The skeleton in some of this sub-family is extremely modified, so as to allow the Insects to pack themselves up in repose; the head is folded in over the chest, and a cavity existing on the breast is thus closed by the head; in this cavity the antennae and the prominent mouth-parts are received and protected; the legs shut together in an equally perfect manner, so that no roughness or chink remains, and the creature looks like a little hard seed. Anobium striatum is a common Insect in houses, and makes little round holes in furniture, which is then said to be "worm-eaten." A. (Xestobium) tessellatum, a much larger Insect, has proved very destructive to beams in churches, libraries, etc. These species are the "death-watches" or "greater death-watches" that have been associated with the most ridiculous superstitions (as we have mentioned in Volume V., when speaking of the lesser death-watches, or Psocidae). The ticking of these Insects is really connected with sex, and is made by striking the head rapidly against the wood on which the Insect is standing.
The very anomalous genus Ectrephes (Fig. 128) is found in ants' nests in Australia. Westwood placed it in Ptinidae. Wasmann has recently treated it as a distinct family, Ectrephidae, associating it with Polyplocotes and Diplocotes, and treating them as allied to Scydmaenidae.
