MEANS OF DEFENCE OF INSECTS. 455 



You have doubtless often observed a black beetle crossing pathways 

 with a slow pace, which feeds upon the different species of bedstraw 

 (Galium), called by some the bloody-nose beetle (Timarcha tenehricosa). 

 This insect, when taken, usually ejects from its mouth a clear drop or two 

 of red fluid, which will stain paper of an orange color. The carrion- 

 beetles {Sil;pha and Necrophorus), as also the larger Carabi, defile us, if 

 handled roughly, with brown fetid saliva. Mr. Sheppard having taken 

 one of the latter (C. violaceus), applied it in joke to his son's face, and 

 was surprised to hear him immediately cry out as if hurt: repeating 

 the experiment with another of his boys, he complained of its making him 

 smart : upon this he touched himself with it, and it caused as much pahi 

 as if, after shaving, he had rubbed his face with spirits of wine. This he 

 observed was not invariably the case with this beetle, its saliva at other 

 times being harmless. Hence he conjectures that its caustic nature, in 

 the instance here recorded, might arise from its food ; which he had rea- 

 son to think had at that time been the electric centipede (Geophilus clec- 

 tricus). Lesser having once touched the anal horn of the caterpillar of 

 some sphinx, suddenly turning its head round it vomited upon his hand a 

 quantity of green viscous and very fetid fluid, which, though he washed it 

 frequently with soap and fumed it with sulphur, infected it for two days.^ 

 Lister relates that he saw a spider, when upon being provoked it attempted 

 to bite, emit several times small drops of very clear fluid.^ Mr. Briggs 

 observed a caterpillar caught in the web of one of our largest spiders, by 

 means of a fluid which it sent forth entirely dissolve the great breadth of 

 threads with which the latter endeavored to envelop it, as fast as produced, 

 till the spider appeared quite exhausted.^ The caterpillars also of a par- 

 ticular tribe of saw-flies, remarkable for the beautiful pennated antennae of 

 the males {Pteronusy, when disturbed eject a drop of fluid from their 

 mouth. Those of one species inhabiting the fir-tree {Ft. Pini) are ordi- 

 narily stationed on the narrow leaves of that tree — which they devour 

 most voraciously in the manner that we eat radishes — with their head 

 towards the point. Sometimes two are engaged opposite to each other on 

 the same leaf. They collect in groups often of more than a hundred, and 

 keep as close to each other as they can. When a branch is stripped they 

 all move together to another. If one of these caterpillars be touched or 

 disturbed, it immediately with a twist lifts the anterior part of its body, 

 and emits from its mouth a drop of clear resin, perfectly similar both in 

 odor and consistence to that of the fir.-^ What is still more remarkable, no 

 sooner does a single individual of the group give itself this motion, than all 

 the rest, as if they were moved by a spring, instantaneously do the same.^ 

 Thus these animals fire a volley, as it were, at their annoyers, the scent of 

 which is probably sufficient to discomfit any ichneumons, flies, or preda- 

 ceous beetles that may be desirous of attacking them. 



Amongst those which annoy their enemies by the emission of fluids 



' Lesser, 1. i. 284. note 6. ^ De Ara?ieis, 27. 



' This gentleman is of opinion that spiders possess the means of re-dissolving their webs. 

 He observed one, when its net was broken, run up its thread, and gathering a considerable 

 mass of the web into a ball, suddenly dissolve it with fluid. He also observes, that when 

 winding up a powerful prey, a spider can form its thread into a broad sheet. 



* Jurine, Hymenopt. t. vi. f. 8. ^ De Geer, ii. 971. 



® I owe the knowledge of this circumstance lo Mr. MacLeay. 



