78 BRITISH INSECTS 



The prothorax is loosely jointed to the mesothorax, 

 and there is a dagger-like projection, or "prosternal 

 process," on the underside of the former. By suddenly 

 forcing this process into a groove or cavity of the 

 mesothorax, the beetle is able to hurl itself high into 

 the air. The larvae of the common click-beetles are 

 the " wireworms," which are so injurious to cultivated 

 crops. 



Before concluding this chapter, mention must be 

 made of the little family Stylopida. It comprises 

 certain very small insects whose structure is so re- 

 markable that some entomologists treat them as a 

 separate order ; the majority, however, regard them as 

 aberrant beetles. The males have the fore-wings 

 greatly reduced and curiously twisted ; but their hind- 

 wings are broad, and are folded lengthwise when not 

 in use. The antennas are branched and the mouth- 

 parts feeble. The females are blind and worm-like, 

 and spend their lives within the bodies of bees and 

 other insects, where they are visited by the free-flying 

 males. The minute, active larvae are hatched within 

 the mother's body, and swarm upon the host insect. 

 If the latter should be a bee, the larvae are conveyed 

 to its nest, and some of them bore into bee-grubs, 

 and change to legless maggots. The bee and its 

 parasite develop simultaneously ; but whereas the 

 female Stylopid remains a parasite throughout its life, 

 the male escapes soon after its host becomes a winged 

 insect. 



