INTRODUCTION. 7 
The beetles and borers. — The order Coleoptera comprises about 100,000 
species of beetles, divided into a large number of families. The beetles 
are easily recognized by the hard, sheath-like fore wings which pro- 
tect the hind wings ; their jaws are stout and thick, more or less 
toothed, and adapted for biting. 
The larvae of beetles are called " grubs." They have been thus 
characterized in the author's " Guide to the Study of Insects : " 
The larvae, when active and not permanently inclosed (like the Cnrculio) in the 
substances which form their food, are elongated, flattened, worm-like, with a large 
head, well developed mouth parts, and with three pairs of thoracic feet, either 
horny or fleshy and retractile, while there is often a single terminal prop-leg on the 
terminal segment and a lateral horny spine. The larvae of the Cerambycidce are 
white, soft, and more or less cylindrical, while those of the Curculionidce are footless, 
or nearly so, and resemble those of the gall-flies, both hymenopterous and dipterous. 
The pupae have free limbs, and are either inclosed in cocoons of earth or, if 
wood-borers, in rude cocoons of fine chips and dust, united by threads or a viscid 
matter supplied by the insect. * * * Generally, however, the antennae are folded 
on each side of the clypeus, aud the mandibles, maxillae, and labial palpi appear as 
elongated papillae. The wing-pads being small, are shaped like those of the adult 
Meloe. and are laid upon the posterior femora, thus exposing the meso- and meta- 
thorax to view. The tarsal joints lie parallel on each side of the middle line of the 
body, the hinder pair not reaching to the tips of the abdomen, which ends in a pair 
of acute, prolonged, forked, incurved, horny hooks, which must aid the pupa in 
working its way to the surface when about to transform into the beetle. 
Most of the destructive kinds belong to the following families : 
Body of beetle, broad, flat, hard ; antennae short, serrated. Larva with head and 
first succeeding segment very broad aud flat Buprestidce. 
Body of beetle more or less cylindrical, with very long, slender antennae ; larva? 
called "borers," their bodies cylindrical, usually footless Cerambycidce. 
Small cylindrical beetles, with no snout, called bark-borers ; larvae footless, thick, 
cylindrical, pointed at each end Scolytidce. 
Hard-bodied beetles, called "weevils," with a long beak or snout, with jaws at tne 
end ; larvae grub like, footless, thick and fleshy Curculiotiidce. 
Moths and butterflies. — While a few caterpillars (mostly of the family 
^geriadse and the Cossidse) bore into the trunk and branches of trees, 
the great bulk devour the leaves. Caterpillars are provided with 
stout, toothed jaws (mandibles) for cutting leaves. They are voracious 
feeders, as will be seen by the following extract from Mr. L. Trouvelot 
in Packard's " Guide to the Study of Insects : n 
Caterpillars gi ow very rapidly and consume a great quantity of food. Mr. Trouve- 
lot gives us the following account of the gastronomical powers of the Polyphemus 
caterpillar: " It is astonishing how rapidly the larva grows, and one who has no 
experience in the matter could hardly believe what an amount of food is devoured 
by these little creatures. One experiment which I made can give some idea of it. 
When the young silk-worm hatches out it weighs one-twentieth of a grain ; when 
ten days old it weighs half a grain, or ten times its original weight; twenty days 
old it weighs 3 grains, or sixty times its original weight; thirty days old it weighs 
31 grains, or 620 times its original weight; forty days old it weighs 90 grains, or 
1,800 times its original weight ; fifty-six days old it weighs 207 grains, or 4,140 times 
its original weight. 
When a worm is thirty days old it will have consumed about 90 grains of fpod ; but 
when fifty-six days old it is fully grown and has consumed not less than one hundred 
