12 INSECTS INJURIOUS TO VEGETATION. 



ties, 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 pupse nearly 

 hke the adult insect, but wanting wings. 



The various kinds of field and house bugs give out a strong and dis- 

 agreeable smell. Many of them, (some PentatomadcB and LygceidcBy 

 Cimicidce, Reduviadce, Hydrometrad(B, Nepadce, and Notonectadce), 

 live entirely on the juices of animals, and by this means destroy great 

 numbers of noxious insects ; some are of much service in the arts, 

 affording us the costly cochineal, scarlet grain, lac, and manna ; but 

 the benefits derived from these are more than counterbalanced by the 

 injuries committed by the domestic kinds, and by the numerous tribes 

 of plant-bugs, locusts or cicadae, tree-hoppers, plant-lice, bark-lice, 

 mealy bugs, and the like, that suck the juices of plants, and require 

 the greatest care and watchfulness on our part to keep them in check. 



4^, — Neuroptera [Drngon-Jiies, Lnce-winged Jlies ; May- 

 Jlies, Ant-lion, Day-fly, White ants, &fc.). Insects with jaws, 

 four netted wings, of which the hinder ones are the largest, 

 and no sting or piercer. Transformation complete, or partial. 

 Larva and pupa various. 



The white ants, wood-lice, and wood-ticks {Termitidce. and Psoclii- 

 dce), the latter including also the little ominous death-watch, are 

 almost the only noxious insects in the order, and even these do not 

 injure living plants. The dragon-flies, or, as they are commonly 

 called in this country, devil's needles (Libelluladce), prey upon- gnats 

 and mosquitos ; and their larvae and pupae, as well as those of the 

 day-flies (£j)/temerad«), semblians [SemMididce), and those of some of 

 the May-flies, called cadis-worms {Phryganeadce), all of which live in 

 the water, devour aquatic insects. The predaceous habits of the ant- 

 lions [MyrmeJeonlidcB) have been often described. The lace-vvlnged 

 flies {Henierobiadce), in the larva state, live wholly on plant-lice, 

 great numbers of which they destroy. The mantispians (Mantis- 

 padcs), and the scorpion-flies {PanorpadcB), are also predaceous 

 insects. 



5. — Lepidoptera [Butterflies and Moths). Mouth with 

 a spiral sucking-tube ; wings four, covered with branny scales. 

 Transformation complete. The larvae are caterpillars, and 



