Farasitic Beetles. 411 



elytra, witli conspicuous and strongly pectinated black antennae, 

 and the female being apterous and slug-shaped, having, indeed, 

 been described as belonging to a separate genus, Cochlceoctonus, 

 founded upon it, and named in allusion to its habits. As also 

 in the glow-worm, the resemblance between the perfect female 

 and full-grown female larva is considerable. 



The ordinary associations of beetles with other insects are 

 purely for the purposes of preying upon them or their leavings ; 

 but some few are sufficiently interesting to be noticed. The 

 most frequent and unvarying alliances of this class are, perhaps, 

 those of certain of the Nitidiilidce (e.g., Epurcea 10-guttata, 

 Soronia, grisea and 8. punctatissima, Gryptarcha strigata and 

 C. imperialis, and, I suspect, the very rare Thalycra sericea) 

 and Aleocharidce (Homalota cinnamomea and H. hospita) with 

 the goat-moth (Cossus ligmperda) • in and about the burrows 

 made in the solid wood by the large naked red fleshy larva of 

 which insect most of them may be readily found, and some- 

 times in profusion — no matter in what tree, be it oak, elm, 

 willow, or poplar, the Lepidopterous devastator may be 

 ploughing its deep tracks. The exudation of sap and quan- 

 tities of wet woody excrement, caused and left behind by this 

 caterpillar, strongly impregnated, moreover, with its peculiarly 

 rancid odour, seem to act as a never-failing attraction to the 

 above-mentioned beetles (as the collector well knows), and to 

 many others ; amongst them being the very rare Quedius dila- 

 tatus, a large black Braclielytron, formerly only known to occur 

 in the nests of the common hornet (Vespa crabro), under the 

 protection of whose sting (by what means diverted from itself 

 we cannot tell) it may readily be believed that it was safe from, 

 capture. M. Chevrolat, a distinguished French entomologist, 

 has, however, recently detected it haunting the burrows of the 

 goat-moth larva, coursing rapidly in and out of the galleries 

 by night ; and it has since his discovery been taken under 

 similar circumstances in this country. There can be little 

 doubt, from the habits of certain other Quedii (Q. Icevigatus, 

 cruentus, xanthopus, scitus, longicornis, and truncicola) frequent- 

 ing trees, that this beetle merely exhibits a preference for such 

 localities in consequence of the number of other insects also 

 attracted to them, upon which it preys. 



Many other beetles also found under or about bark are pre- 

 daceously parasitic upon insects either of their own or another 

 order. Of these, Ips and Rhizophagus , attendant upon the 

 genuine wood-feeders, Hylesinus, Hylastes, and Hylurgus (as 

 mentioned in No. LYL, p. 133), are notable examples; and 

 with them may be classed two very rare species, Nemosom.a 

 elongata, one of the Trogositidce, and Golydium elongatum, the 

 type of the Golydiadce, both of which are of an elongate tere- 



