196 



ARTHROPODA 



The larvae are called the " round-headed borers " to distinguish 

 them from the Buprestid larvae which are flat-headed. The 

 Tenebrionidae include the ordinary meal worm which is a minor pest 

 in spoiled grain, but is useful in feeding pet birds and " horned 

 toads." The Meloidae, or blister beetles, feed on plants. They are 

 used to supply the cantharides or Spanish fly used for blistering. 

 The snout beetles {Rhynchophord) include the bark beetles, most 

 destructive to trees, and the Curculios or weevils. The Mexican 

 cotton-boll-weevil has cost the South many thousands of dollars by 

 destroying its cotton, while the alfalfa weevil is a serious pest on the 

 West Coast. 



Fig. 92. Blastophagay the insect which pollinates figs. (U. S. D. A.) 



Order 19. Hymenoptera. {Gall-flies, Ants, Wasps and Bees.) — 

 The sawflies, horntails and gall flies are boring Hymenoptera whose 

 larvae feed on the leaves of shrubs and in some cases induce develop- 

 ment oi galls. 



The chalcid flies {Chalcidoidae), minute parasites attacking the 

 eggs and larvae of injurious insects, are for the most part extremely 

 beneficial to man. One species is responsible for the fertilization 

 of the fig. The fig-wasp has recently been introduced from Asia 

 Minor into California. The gall-flies {Cynipoidea) utilize a sharp 

 ovipositor to thrust their eggs into green stems of oaks, roses and a 

 few other plants where the hatching larvae stimulate the plant to 



