COLEOPTEEA. — ORTHOPTERA. — HEMIPTEEA. 11 



Coleoptera (some Staphylinidce and Nitiduladce, Dia- ^ig. 2. 

 perididce, some Serropalpidce, Mycetophagidce, Eroty- 

 lidce, and JEndomychidce) 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 (Elateridce), dark- 

 ling-beetles (Tenebrionidce), (Figs. 1-3,) and many Fig. 3. 

 bark-beetles (Helopidce, Cisteladce, Serropalpidce, (Ede- 

 meradce, Cucujadce, and some Trogositadce), which, liv- 

 ing 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 contribut- 

 ing to destroy and reduce to dust plants that have passed imago, 

 their prime and are fast going to decay. And, lastly, 

 the blistering-beetles (Cantharididce) have, for a long time, been 

 employed with great benefit in the healing art. 



2. Orthoptera ( Cockroaches, Crickets, Grasshoppers, <fc). 

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

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

 which are folded in plaits, like a fan. Transformation par- 

 tial. Larvas and pupae active, hut wanting wings. 



All of the insects of this order, except the camel-crickets (Man- 

 tidce), which prey on other insects, are injurious to our household 

 possessions, or destructive to vegetation. 



3. Hemiptera (Bugs, Locusts, Plant-lice, $c}. Insects 

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

 uppermost are generally thick at the base, with thinner 

 extremities, which lie flat, and cross each other on the top 

 of the hack, or are of uniform thickness throughout, and 

 slope at the sides like a roof. Transformation partial. Larvae 

 and pupas nearly like the adult insect, but wanting wings. 



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

 disagreeable smell. Many of them (some PentatomacUe and Lij- 



