HOW TO KNOW THE IMMATURE INSECTS 



79a. Head swollen laterally, and much broader than thorax; cardo of 

 normal shape and position; maxillary articulating area round and 

 well developed; hypostomal inner margin concave between fossa 

 for mandible and posterior end of cardo. 

 Fig. 271 Genera Prosfomis and Dryocoia, CUCUJIDAE 



Prostomis mandibularis, here figured is almost 

 cosmopolitan in its distribution. The group is a 

 relatively small one. 



The family Cucujidae has about a thousand 

 known species of rather widely diversified forms. 

 Both the larvae and the adults are often serious 

 pests of stored food products and as such have 

 been distributed world wide. Many of the species 

 live under the bark of trees, some being plant feed- 

 ers and others feeding upon the small animal forms 

 they find associated with them. The larvae are 



toniis" mandibularis usually elongate and flattened. 



Fab.; b, Maxilla. 



Fig. 271. a, Pros- 



79b. Different development of some, or all, of the 4 characters. 



80 



JLABIUM 



80a. Maxillae appearing protracted in front of the ^-^"xfw^^'' 

 mandiblular articulations by a complete or / I \ 



partial elimination of the cardines. 



Fig. 272. 



81 



Fig. 272. Ventral 

 aspect of head. 



80b. Maxillae deeply retracted. Fig. 273 



Fig. 273. Ventral 

 aspect of head. 



81a. Cerci present; terga without glandular openingb. 



82 



105 



