184 



MEANS OF DEFENCE OF INSECTS. 



at their last moult, previous to their assuming the pupa (in 

 which state they are protected by other contrivances), appear 

 with a smooth skin, without any of the tubercles, hairs, or 

 spines for which they were before remarkable. 1 Wonder- 

 ful are the varieties of this kind which insects exhibit : — 

 but I shall only here select a few facts more particularly con- 

 nected with my present subject. The caterpillar of the great 

 tiger-moth (Euprepia Cajd), which is beset with long dense 

 hairs, when rolled up — an attitude it usually assumes if 

 alarmed — cannot then be taken without great difficulty, 

 slipping repeatedly from the pressure of the fingers. If its 

 hairs do not render it distasteful, this may often be the 

 means of its escape from the birds. That little destructive 

 beetle, Anthrenus Musorum, which so annoys the entomolo- 

 gist, if it gets into his cabinets, when in the larva state being 

 covered with bunches of diverging hairs, glides from between 

 your fingers as if it were lubricated with oil. The two tufts 

 of hairs near the tail of this are most curious in their struc- 

 ture, being jointed through their whole length, and ter- 

 minating in a sharp halberd-shaped point. 2 I have a small 

 lepidopterous caterpillar from Brazil, the upper side of which 

 is thickly beset with strong, sharp, branching spines, which 

 would enter into the finger, and would probably render it a 

 painful morsel to any minor enemy. 



The powers of annoyance by means of their hairs, with 

 which the moth of the fir, and the procession-moth, before 

 noticed, are gifted, are doubtless a defensive armour to them. 

 Madame Merian has figured an enormous caterpillar of this 

 kind, — which unfortunately she could not trace to the per- 

 fect insect, — by the very touch of which her hands, she says, 

 were inflamed, and that the inflammation was succeeded by 

 the most excruciating pain. 3 The vesicatory beetles, likewise 

 (Cantharis vesicatoria, &c), are not improbably defended from 



1 Reaum. v. 94. 



2 This was first pointed out to me by Mr. Briggs of the post-office, who sent 

 me an accurate drawing of the animal and of one of* its hairs. I did not at that 

 time discover that it had been figured by De Geer, iv. t. viii. f. 1.7. 



3 Insect. Surinam, t. 57. Two different species of caterpillars apparently re- 

 lated to this of Madame Merian were in the late Mr. Francillon's cabinet, and are 

 now in my possession. 



