ENDOPTERYGOTA 



431 



is an active campodeiform larva which attaches itself to its host. The 

 second instar which is enclosed with an abundance of honey in the 

 cell of the bee is intermediate in form between the campodeiform and 

 the cruciform types, legs being present, but very small. The third 

 stage is a legless maggot. From this series it may be inferred that the 

 form of larva in coleoptera is related to the ease or difficulty with 

 which food is obtained. 



In such a large order of insects it is to be expected that all manners 

 of habit and food will be found. Beetles occur in large numbers in 

 water, soil, and plant tissues. Circumscribed environments like dung, 

 rotting vegetation, wood and fungi are never without prominent 



Fig. 320. The hornet, Vespa crabro. A, Larva. B, Pupa. C, Adult o . 



coleopteran associations. A large number, such as many coccinellids 

 (lady birds), carabids, e.g. Carahiis violaceus, and staphylinids, e.g. 

 Ocypiis olens, are carnivorous and to this extent useful insects. On the 

 other hand, among the phytophagous forms are to be found the most 

 serious agricultural pests, the boll weevil, Anthonomus grandis, causing 

 so much damage to the cotton crop in America that it has been seriously 

 proposed to cease growing cotton for a period of time in order to 

 eradicate this pest. A large number cause considerable damage to 

 timber, probably the most notable being Xestobium rufomllosumy the 

 death-watch beetle, destructive to structural timber. 



