266 POPULAR EISTOMOLOGY. 



being destroyed by their attacks; and the tropical palms 

 afford nourishment to many large exotic Beetles. The 

 Dipterous and Lepidopterous larvse take also an active part 

 in destroying the roots and stems of plants and trees. Leaf- 

 devourers are very numerous; among Beetles the Cliry- 

 somelidcE, both in the perfect and imperfect state^ choose 

 leaves as their food. Burmeister mentions the curious fact^ 

 that Beetles and their larvse never consume the leaf from 

 the margin like the caterpillars of the Lejoidojjtera, but bite 

 a hole in the centre^ round which they eat : thus these 

 destroyers may be distinguished merely by the appearance 

 of the leaf on which they have been feasting. The Hyme- 

 nopterous insects are many of them leaf-eaters, and the 

 family TenthredinidcE (Saw-flies) sometimes destroy whole 

 plantations ; but by no order are leaves so nniversally used 

 for food, as among the Lepidoptera. The oak feeds nume- 

 rous caterpillars; according to Eoesel, this tree supports 

 200 distinct species, and every forest-tree is supposed to 

 nourish many varieties; most of our fruit-trees also feed 

 their peculiar tenants. Grasshoppers will eat almost every 

 kind of leaf, but give the preference to grass. The devasta- 

 tion of the Locust is too well known to need description, 

 and happily for us we are exempt from its ravages. 



