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THE STUDY OF INSECTS. 
Family COCCIM (Coc'ci-dae). 
The Scale-bugs or Bark-lice , Mealy-bugs , and others . 
The family Coccidas includes the Mealy-bugs, the Scale* 
bugs or Bark-lice, and certain other insects for which there 
are no popular names. In this family we find those mem¬ 
bers of the Hemiptera that depart most widely from the 
type of the order. In fact this is a very anomalous group, 
the species differing greatly in appearance, habits, and meta¬ 
morphoses from those of the most closely allied families. 
Not only do the members of this family appear very unlike 
other insects, but there is a wonderful variety of forms within 
the family, and even the two sexes of the same species differ 
as much in the adult state as members of distinct orders. 
The males of Coccidae, unlike all other Hemiptera, 
undergo a complete metamorphosis. The adult males have 
only a single pair of wings, the hind wings being represented 
by a pair of club-like halteres. Each of these is furnished 
with a bristle, which in all the species we have studied is 
hooked, and fits in a pocket on the wing of the same side 
(Fig. 202). The male in the adult state has no organs for 
procuring food, as the mouth-parts disappear during the 
metamorphosis of the insect, and a second pair of eyes ap¬ 
pear in their place. The adult female is always wingless, 
and the body is either scale-like or gall-like in form, or grub- 
like and clothed with wax. The waxy covering may be in 
the form of powder, of large tufts or plates, of a continuous 
layer, or of a thin scale, beneath which the insect lives. 
Among the Coccidae are found many of the most serious 
pests of horticulturists. Scarcely any kind of fruit is free 
from their attacks, and certain species of scale-insects and 
mealy-bugs are constant pests in conservatories. The ease 
with which these insects or their eggs can be transported 
long distances while yet alive, on fruit or living plants, has 
