HOW TO KNOW THE IMMATURE INSECTS 



75b. Bcdy fusiform; mandible with 2 apical teeth 76 



76a. Cutting edge of mandible be- 

 hind the apical teeth with a 

 single rounded projection; re- 

 tinaculum short and broad. 

 Fig. 266. .Subfamily Clado- 



Fig 266. a, Pharaxonotho kirshi Reit.; xeninae, EROTYLIDAE 



b, Mandible. 



76b. Cutting edge of mandible behind the apical teeth multiserrate; 

 retinaculum long and slender. 

 Fig. 267 Family CRYPTOPHAGIDAE 



About 800 species are describ- 

 ed. They are found on fungi and 

 decaying organic matter. A few 

 are found in the nests of ants and 

 wasps where they are thought to 

 be predators or scavengers. 



^triffACu 



Sturm. 



Cryptophagus saginatus 



Mandible. 



77a. Cerci absent. Fig. 268. 



Fig. 268. Saw-toothed grain beetle, 

 Oryzaephilus surinamensis (L.) 



Group Silvanini, CUCUJIDAE 



The genus SiLvanus contains 55 

 known species. The larvae of 

 some of the species are very de- 

 structive to stored grain products, 

 dried fruit, etc. Their small size 

 often permits them to get a good 

 start before being detected. 



77b. Cerci present. Fig. 269. 



Fig 269. Cucuius clavipes Fob. 



Family CUCUJIDAE 



This family consists of about 

 1,000 species. The development of 

 many species takes place in grain 

 and grain products. A few are 

 predacious upon wood-boring in- 

 sects and also on termites. 



78a. Mentum with only apex free, or small, or in- 

 distinct by fusion with other areas (except in 

 Sphindidae, mentum free to base and distinct, 

 but appearing together with a mandible pro- 

 vided with retinaculum and a 9th abdominal 

 segment without cerci). Fig. 270 79 



Fig. 270. Mentum 

 and maxilla. 



78b. Mentum with more than apex free, often free to base, always well 

 developed and distinct 93 



104 



