32 



INTRODUCTION. 



in the case of the Teneeeionidje, the larvss of which, as a rule, 

 are elongate, linear, parallel-sided, flattened, or cylindrical grubs, 

 presenting a very close superficial inter-resemblance ; and this is 

 more or less maintained (with exceptions) throughout the Hete- 

 eomeea, thus serving to indicate that they probably constitute a 

 natural division. 



The most extraordinary forms are found among certain of the 

 water-beetles (e. g. Haliplid^: and G-yeinid^e) and the Dee- 

 mestid.e, the larvae in the former being furnished with long 

 lateral and caudal appendages, and in the latter with a dense 

 clothing of curiously arranged hairs. 



The life-history of certain Coleoptera is exceedingly interesting, 

 especially of those forms which undergo what is known as Hyper- 

 metamorpJiosis, of which only a very few examples have been 

 adequately investigated. Many larvae of all orders are provided 

 with special modifications to enable them to adapt themselves to 

 their proper habits of life ; but certain insects, with a very com- 

 plicated life-history, require several further modifications in order 

 to suit their altered circumstances. This is especially the case 

 with those Coleopterous larvae (Meloe, &c.) that are parasitic on 

 certain bees. The best known instance is that of Sitaris Jiumeralis, 



Fig. 18. — Life-history of Sitaris muralis. a, triungulin or 1st larva : g, anal 

 spine erect and claspers of a ; b, 2nd larva ; e, pseudo-pupa ; f, 3rd larva ; 

 c, true pupa ; d, imago. (After Kidley & Packard.) 



an account of which has been often given, but may perhaps be 

 repeated. The observations were first made by M. Fabre, of 

 Avignon. The eggs are laid by the female near the nest of a bee 

 (Anthophora), and from these emerge the first or " triungulin " 

 larvae, which are very small, hard-skinned, with strong jaws, and 

 long legs and antennae. According to Fabre they remain motion- 

 less and without taking food until the following spring, when they 

 become very active and hook themselves on to the hairs of the male 

 bees, from which they transfer themselves to the females, and 

 from these to the eggs of the bee, which are laid in separate cells 

 filled with honey. After devouring the egg the triungulin assumes 



