262 MEANS OF DEFENCE OF INSECTS. 



Other form compartments, in the centre of each of which 

 is a hole ^. 



Under this head I shall call your attention to another 

 circumstance that saves from their enemies innumerable 

 insects: — I mean their coming forth for flight or for food 

 only in the night, and taking their repose in various 

 places of concealment during the day. The infinite 

 hosts of moths (P7/«Zirwff, L-)) — amounting in this coun- 

 try to more than a thousand species, — with few excep- 

 tions, are all night-fliers. And a considerable propor- 

 tion of the other orders, — exclusive of the Hymenoptera 

 and Diptera, which are mostly day-fliers, — are of the 

 same description. Many larvce of moths also come out 

 only in the night after their food, lying hid all day in 

 subterraneous or other retreats. Of this kind is that of 

 Fimiea pulla and Nj/ctewbius, whose proceedings have 

 been before described''. The caterpillar of another 

 moth (Noctua suhterraneay F.) never ascends the stems 

 of plants, but remains, a true Troglodyte, always in its 

 cell under ground, biting the stems at their base, which 

 falling, bring thus their foliage within its reach '^. 



The habitations of insects are also usually places of 

 retreat, which secure them from many of their enemies : 

 — but I have so fully enlarged upon this subject on a 

 former occasion'', that it would be superfluous to do more 

 than mention it here. 



I am now to lay before you some examples of the con- 

 trivances, requiring skill and ingenuity, by which our 

 busy animals occasionally defend themselves from the 



^ Reiuim. iii. 170. Dc Geer, ii. 519. 545. Plate XVII. Fig. 11. 

 '■ Vol. I. 453. ^ Fab. Ent. Syst. Em. iii. 70. 200. 



'' Vol. I. 432- 



