STREPSIPTERA 177 



The mouth-parts of the males are greatly reduced and the mouth 

 opening is small. The labrum and labium are wanting as distinct parts. 



Fig. 310. — A male stylopid. (After Pierce.) 



In some species the mandibles are slender, curved and scimitar-like while 

 the maxillae are two-segmented. In others the mandibles are greatly 

 reduced. 



The three pairs of legs are similar in form and the abdomen is com- 

 posed of ten segments. 



The adult female is very degenerate in form. That part of the body 

 which projects from the body of the host is the cephalothorax, the head 

 and thorax being consolidated into a single disk-like region. The abdo- 

 men, which is within the body of the host, is a great sac filled with eggs. 

 The body of the adult female is inclosed in the skin of the last larval 

 instar, which is termed the puparium; but there is no pupal stage in 

 this sex. 



Owing to their parasitic life the development and life-cycles of these 

 insects are very complex and remarkable. The young larva is very active 

 for it must hunt around and find a host insect. Many of these larva;, of 

 course, never find a host and therefore starve. This contingency is 

 provided for, however, because a female stylopid has been known to 

 produce as many as 2000 young. After the young stylopid finds a host 

 it bores to the inside of the body and begins its parasitic life. The 

 larvae pass through several molts and assume different forms in their 

 progress toward maturity, the females after the early stages differing in 

 their development from the males. The female remains larval-like in 

 form even when full-grown. 



The order, Strepsiptera, is well represented in this country, ninety- 

 seven species having been listed and probably there are many undis- 

 covered species. 



