MEANS OF DEFENCE OF INSECTS. 231 



herself in stringing them on a thread ; when to her great 

 surprise, the poor animals beginning to move and strug- 

 gle for their liberty, crying out and running away in the 

 utmost alarm she threw down her prize a . The golden- 

 wasp tribe also, (Chrysis and Parnopes,} all of which I 

 suspect to be parasitic insects, roll themselves up, as I 

 have often observed, into a little ball when alarmed, and 

 can thus secure themselves the upper surface of the 

 body being remarkably hard, and impenetrable to their 

 weapons from the stings of those Hymenoptera whose 

 nests they enter with the view of depositing their eggs 

 in their offspring. Latreille noticed this attitude in 

 Parnopes camea, which, he tells us, Bembex rostrata 

 pursues, though it attacks no other similar insect, with 

 great fury ; and, seizing it with its feet, attempts to dis- 

 patch it with its sting, from which it thus secures itself b . 

 Other insects endeavour to protect themselves from 

 danger by simulating death. The common dung-chafer 

 (Geotrupes stercorarius) when touched, or in fear, sets 

 out its legs as stiff 1 as if they were made of iron-wire 

 which is their posture when dead and remaining per- 

 fectly motionless, thus deceives the rooks which prey 

 upon them, and like the ant-lion before celebrated c will 

 eat them only when alive. A different attitude is as- 

 sumed by one of the tree- chafers (Hoplia pulverulenta) 

 probably with the same view. It sometimes elevates its 

 posterior legs into the air, so as to form a straight verti- 

 cal line, at. right angles with the upper surface of its 

 body. Another genus of insects of the same order, the 

 pill-beetles (Byrrhus], have recourse to a method the re- 



a Hill's Swamm. i. 174. b Ann. du Mus. 1810. 5. 



r VOL. I. p. 426. 



