356 A COURSE ON ZOOLOGY. 



bore into the wood. The rose beetle, the asparagus 

 beetle, sugar-cane beetle, and carpet beetle the latter 

 being exceedingly destructive to woollens of all kinds 

 are only too well known. 



Of the dermiptera, the earwigs destroy fruits and 

 flowers. 



Orthoptera. The cockroaches eat and soil our food; 

 grasshoppers and locusts devour roots and young sprouts. 



Hemiptera. Plant lice live socially on most plants ; 

 they cause a more or less rapid destruction by absorbing 

 all the nutritive juices. The phylloxera, so fatal to the 

 grape-vine, is closely related to the plant lice. The har- 

 lequin cabbage-bug and tree-hoppers are hemiptera. 



Neuroptera. The termites, which will presently be de- 

 scribed, are particularly injurious to wooden construc- 

 tions. 



Hymenoptera, The damage caused by ants and wasps 

 has already received notice. Certain of these insects are 

 very injurious to trees. 



Lepidoptera. In the state of larva or caterpillar 

 nearly all this order are destructive to certain vege- 

 table or animal matters. We may cite all the varieties 

 of silk-worm, the cabbage-worm, larch-lappet, hemlock- 

 worm, corn-worm, and the peach- and apple-twig moths. 



We will terminate with a few details concerning some 

 species whose history is of particular interest. 



Grasshoppers have very long hind legs and a powerful 

 masticating apparatus. But they are not nearly as 

 much dreaded as their near relatives, the migratory lo- 

 custs. At certain epochs innumerable legions of these 

 insects start from desert regions of the Rocky Mountains, 

 of Arabia and Tartary. and rise high in the atmosphere, 

 until they encounter winds that carry them great dis- 



