HEMIPTERA, 



135 



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 of 

 the species I have studied is hooked, and fits in a pocket on the 

 wing of the same side (Fig. 120, \a\ The male in the adult state 

 has no organs for procuring food, as the mouth-parts disappear 



FIG. 120 A sp idiotu s nerii. i, scales on leaves of acacia, natural size; i<, adult male, enlarged ; 

 scale of male, enlarged ; ic, scale of female, enlarged. (From the Author's Report for 1880.) 



during the metamorphosis of the insect, and a second pair of eyes 

 appear 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, be- 

 neath 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 caused many species that infest cultivated plants to be- 

 come world-wide in distribution. 



