244 MEANS OF DEFENCE OF INSECTS. 



it can give ten or twelve good discharges; but afterwards, 

 instead of smoke it emits a yellow or brown fluid. By 

 bending the joints of its abdomen it can direct its smoke 

 to any particular point. M. Leon Dufour observes that 

 this smoke has a strong and pungent odour, which has 

 a striking analogy with that exhaled by the Nitric Acid. 

 It is caustic, reddening white paper, and producing on 

 the skin the sensation of burning, and forming red spots, 

 which pass into brown, and though washed remain 

 several days a . 



Another expedient to which insects have recourse to 

 rid themselves of their enemies, is the emission of dis- 

 agreeable fluids. These some discharge from the mouth ; 

 others from the anus ; others again from the joints of 

 the lijnbs and segments of the body; and a few from ap- 

 propriate organs. 



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 tenebricosa). 

 This insect, when taken, usually ejects from its mouth a 

 clear drop or two of red fluid, which will stain paper of 

 an orange colour. The carrion-beetles (Silpha and Ne- 

 crophorus\ as also the larger Carabi, defile us, if handled 

 roughly, with brown fetid saliva. Mr. Sheppard having 

 taken one of the latter (C. violacem\ applied it in joke 

 to his son's face, and was surprised to hear him immedi- 

 ately 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 pain as if, after shaving, he had rubbed 

 a Ann. du Mus. xviii. 70, 



