THEIR RELATION TO PLANTS 57 



vegetation among which they Uve. The_y are largely 

 seed feeders when seeds are to be obtained, but eat 

 grassy tissue as well. A character of interest is found 

 at the base of the wings in the males, where the over- 

 lapping parts are ridged and toughened to form a 

 stridulating or musical apparatus of a very effective 

 order. The best known among this type are the Katy- 

 .dids, which are often tree and shrub dwellers but do 

 not differ markedly in other respects from the more 

 lowly meadow inhabitants. 



Fig. 18. — A long-horned grasshopper, Microcentrum sp. 



The crickets are very diverse in their habits, both 

 as to dwelling places and as to food; some confined to 

 vegetable matter only, a few omnivorous and the tree 

 crickets carnivorous. The latter are really the only 

 injurious forms for, while they eat plant lice and similar 

 creatures, they lay their eggs in the shoots of plants 

 and sometimes cause their death; but this is an in- 

 significant item as against their usefulness from the 

 farmer's point of view. 



On the whole, while the order Orthopiera contains 

 many plant destroyers, the destruction is rarely total: 

 that is, it is confined to defoliation which does not 

 threaten the actual life of the plant, however completely 

 it may destroy its value agriculturally. 



