CHAPTER II 
INSECTS 
I NSECTS are easily distinguished from the other jointed animals by many salient characters. 
They have one pair of antennae, two large compound eyes, composed of a great number 
of facets, and sometimes one, two, or three simple eyes placed on the crown or front of 
the head. In its adult condition an insect is composed of three different parts, which can 
be most readily noticed in a wasp. There is the head, with the antenna and mouth-parts; 
the thorax, to which one or two pairs of wings are attached above, and three pairs of legs 
below; and the abdomen. Insects breathe through openings, called “ stigmata,” in the sides of 
the thorax and abdomen. They never possess more than six legs in the perfect state, the 
abdominal legs present in caterpillars, etc., disappearing in the adult condition. They generally 
pass through what is called a “ metamorphosis,” — four different stages of life, called respectively 
egg; larva or caterpillar; pupa, nymph, or chrysalis; and imago, or perfect insect. 
Insects are divided into several large sections, of which the following seven are the most 
important, and many entomologists prefer to include all insects under them : — 
Sheath-winged Insects, or Beetles; Straight-winged Insects, or Earwigs, Cockroaches, 
Soothsayers, Stick-insects, Crickets, Grasshoppers, and Locusts; Nerve-winged or Lace-winged 
Insects, or Dragon-flies and their relatives; Stinging Four-winged Insects, or Ants, Bees and 
Wasps, and their allies; Scale-winged Insects, or Butterflies and Moths; Half-winged Insects, 
or Bugs and Frog-hoppers; Two-winged Insects, or Flies. 
We proceed to notice these orders separately. 
SHEATH-WINGED INSECTS, OR BEETLES 
BY THE REV. THEODORE WOOD, F.E.S. 
Beetles are distinguished from most other insects by the fact that the front wings are 
not employed in flight, but are modified into homey sheaths, which cover and protect the 
lower pair while not in use. This arrangement, however, is also found in the Earwigs as well 
as in the so-called “ Black-beetle” and its allies, and it is to be noted that the wing-cases of 
beetles He evenly side by side together when the wings are folded, while the folding of the wings 
longitudinal. The number of species 
having already been described, of 
in the British Islands, 
several smaller groups, first among 
of the land. Of these the common 
example. It is found on sandy and 
at once by its bright green wing- 
the metallic blue of the abdomen, 
swiftness in the hot sunshine, taking 
and feeds entirely upon other insects, 
group is rich golden green in colour, 
an occasional visitor to Britain, 
where it feeds upon the caterpillars 
and is largely instrumental in 
oak forests. 
Purple Ground-beetle, so plentiful 
by the violet margin to the black 
themselves is transverse as well as 
is very great, upwards of 100,000 
which about 3,400 have been taken 
The order is again divided into 
which stand the predacious beetles 
English Tiger-beetle is a familiar 
peaty heaths, and may be known 
cases, marked with white spots, and 
Thelegsare coppery. Itflieswithgreat 
to wing as readily as a blue-bottle fly, 
Another representative of the 
with coppery reflections. It is only 
but abounds in France and Germany, 
of the famous Processio'nary Moth, 
checking their ravages in the great 
Familiar to almost all is the 
in gardens, and easily recognisable 
Photo by P , Dando^ 
F.Z.S.^ Regent's Park 
TIGER-BEETLE 
TAe colouring of this insect 
is bright green tvith 
•white markings and 
coppery legs 
283 
