COLEOPTERA. — ORTHOPTERA. 
HEMIPTERA. 11 
Coleoptera (some Staphylinidce and NitiduJadce, Dia- Fig. 2. 
peiddidce, some Serropalpidce, Mycetophagidce^ Eroty- 
lidce, and Endomychidce) live altogether on agarics, 
mushrooms, and toadstools, plants of veiy little use to 
man, many of them poisonous, and in a state of decay 
often offensive ; these funorus-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 {TmehrionidcE)^ (Figs. 1 — 3,) and many Fig. 3. 
bark-beetles {Helopidce^ Cisteladce, Serropalpidce, (Ede- 
meradce, Cucitjadce, and some Trogositadce)^ -which, liv¬ 
ing under the bark and in the trunks and roots of old 
O 
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. O RTHOPTERA ( Cockroaches, Criclcets^ GrassJiojyjyers, ^c.). 
Insects with jaws, two rather thick and opaque upper wings, 
overlapping a little on the -back, and two larger, thin wings, 
which are folded in plaits, like a fan. Transformation par¬ 
tial. LarYa3 and pupai active, but wanting wings. 
All of the insects of this order, except the camel-crickets (Jfan- 
tidce), which prey on other insects, are injurious to our household 
possessions, or destructive to vegetation. 
3. Hemiptera (^Bugs, Locusts^ Plant-lice^ Insects 
with a horny beak for suction, four wino-s, Avhereof the 
uppermost 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. Larvte 
and pupte 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 Pentatomadce and Ly- 
Pupa. 
