10 INSECTS INJURIOUS TO VEGETATION. 



tophagidic, Erotylidce., and Endomychidce) live altogether on agarics, 

 mushrooms, and toadstools, plants of very little use to man, many of 

 them poisonous, and in a state of decay often offensive ; these fungus- 

 eaters' are therefore to be reckoned among our friends. There are 

 others, such as the stag-beetles (Lucanidce), some spring-beetles 

 {Elateridcr), darkling-beetles {Tenehrio7iid(E), and many bark-beetles 

 {Helopidcc, Cisteladoi, Serropalpidce, (EdemeradcB, CucujadcB, and some 

 Trogositud(c), which, living under the bark and in the trunks and roots 

 of old trees, though they may occasionally prove injurious, must, on the 

 whole, be considered as serviceable, by contributing to destroy, and 

 reduce to dust, plants that have passed their prime and are fast going 

 to decay. 'And, lastly, the blistering-beetles {Cantharidida) have, for 

 a long time, been employed with great benefit in the healing art. 



2. — Ortiioptera {Cockroaches, Crickets, Grasshoppers, Sfc). 

 Insects with jaws, two rather thick and opake upper wings, 

 overlapping a little on the back, and two larger, thin wings, 

 which are folded in plaits, like a fan. Transformation partial. 

 Larva? and pupse active, but wanting wings. 



All of the insects of this order, except the camel-crickets {ManiidcB), 

 which prey on other insects, are injurious to our household possessions, 

 or destructive to vegetation. 



3. — Hkmiptera {Bugs, Locusts, Plant-lice, Sfc). Insects 

 with a horny beak for suction, four wings, whereof the upper- 

 most are generally thick at the base, with thinner extremities, 

 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 w^anting wings. 



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

 greeable smell. Many of them (some Penlaloinadce and Lygmda;, 

 Cimicidcc, Reduviada;, Hydrometradcc, Nepadcs, 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 cicadte, tree-hoppers, plant-lice, bark-lice, 



