452 



^A^ INTRODUCTION TO ENTOMOLOGY 



The most striking characteristic of this subfamily is that the abdomen 

 of the female is cleft at the caudal end, and at the cephalic end of this 

 cleft there is a pair of triangular or semicircular plates, the anal plates 

 (Fig. 518). 



This is a large subfamily including many genera and species. 

 While the various forms agree in the distinguishing characteristics 

 given above, there are great differences in the appearance of the adult 

 females. Many of them excrete very little wax, the body being 

 practically naked, and the eggs, or the young in the viviparous species, 



Fig. 529. Saissetia olece: 

 enlarged. 



/, adult females on olive, natural size; la, female, 



are deposited beneath the body ; in other species, although the body 

 is nearly naked, the adult female excretes a large, cottony egg-sac; 

 and in still others the body is deeply encased in wax. 



The three following species will serve as examples of those in 

 which the body is naked and which do not form an egg-sac. 



The soft scale, Lecdnium hesperidum. — -This is the commonest 

 and most widely spread member of this subfamily ; it infests a great 

 variety of plants; in the North, it is very common in greenhouses; 

 in the warmer parts of the countr}^ it lives out of doors. The adult 

 female is nearly flat (Fig. 528), and is viviparous. 



