174 Insects: Hemiptera, Neuroptera, Lepidoptera. 



to man. The mole-cricket is one of this class, and in Europe is 

 very troublesome in nurseries and gardens, by eating the roots of 

 trees aud plants. A single brood will destroy a whole seed-bed. 

 By breaking the crust of hardened earth in June, their nests are 

 exposed to the air, and the eggs perish. 



(3.) HEMIPTERA (Bugs, Locusts, Plant-lice, etc.'). 



688. These are insects with a horny beak for suction, four wings, 

 of which the upper are generally thick at the base, with thinner ex- 

 tremities, and which lie flat and cross each other on the top of the back, 

 or are of uniform thickness throughout, and slope at the sides like a 

 roof. Transformation partial, larvae and pupae nearly like the adult 

 insect, but wanting wings. Some, like the cochineal insect, are use- 

 ful, but the damages done by plant-bugs, locusts, tree-hoppers, 

 froth-insects, plant-lice, bark-lice, mealy-bugs, and the like, by 

 sucking the juices of plants, is very great. 



(4.) NEUROPTERA (Dragon-flies, Lace-winged Flies, May-flies, Ant-lion, 

 Day-fly, White Ants, etc.}. 



689. These are insects with jaws, four netted wings, of which 

 the hinder ones are the largest, and no sting. Transformation com- 

 plete or partial, larva and pupa various. White ants, wood-lice and 

 wood-ticks, are almost the only noxious insects of this order, and 

 even these do not injure living plants. Many of them destroy other 

 insects for their food. 



(5.) LEPIDOPTERA (Butterflies, Sphinges, and Moths). 



690. These insects have a mouth with a spiral sucking tube; 

 wings four, covered with branuy scales. Transformation complete. 

 The larvae are caterpillars, and have six true legs, and from four to 

 ten fleshy prop-legs. Pupa with the cases of the wings and of the 

 legs indistinct, and soldered to the breast. 



691. Of the butterflies proper, the forester has not much to com- 

 plain. The perfect insects feed upon flowers, and the larvae upon 

 vegetable substances. They usually change their skins about four 

 times before they come to full size. Their life in the final state is 

 brief, and in the splendor of colors they rival sometimes all other 

 forms of animal life. 



