HOMOPTERA 



453 



The black scale, Saissetia dlece. — This is a well-known pest, es- 

 pecially in California, where it infests various kinds of fruit-trees and 

 other plants. The adult fe- 

 male is dark brown, nearly 

 black, in color; nearly hemi- 

 spherical in form (Fig. 529), 

 often, however, quite a little 

 longer than broad. There is a 

 median longitudinal ridge on 

 the back, and two transverse 

 ridges, the three forming a 

 raised surface of the form of a 

 capital H. 



The hemispherical scale, 

 Saissetia hemisphcerica.— The 

 adult female is nearly hemi- 

 spherical in form, with the 

 edges of the body flattened 

 (Fig. 530). This species is 

 found in conserv^atories every- 

 where, and in the open air in 

 warmer regions. 



Pulvindria. — Those mem- 

 bers of this subfamily in which 

 the adult female is nearly 

 naked but excretes a large 

 cottony egg-sac beneath or be- 

 hind the body, are represented 

 in this/ country by the genus 

 Pulvinaria, of which we have 

 many species. Our best-known 

 species are the two following. 

 The cottony maple-scale, 

 Pulvindria vitis. — This species is common on maple, osage orange, 

 grape, and other plants. Figure 531 represents several adult females 



with their egg-sacs on 

 a cane of grape. 



The maple-leaf 

 pulvinaria, Pulvindria 

 acerlcola . — This 

 species is also found 

 on maple. It differs 

 from the preceding 

 Fig. 53 1 .—Pulvinaria vitir. Species in that the egg- 



sac is much longer 

 than the body of the female, and is formed on the leaves instead of 

 on the stem of the host. 



Ceroplastes. — In this genus the body of the female is covered with 

 thick plates of wax. Alore than sixty species have been described, 



JkaraJd 



Fig. 530. — Saissetia hemispharica: 3, adult 

 females on orange, natural size; 3a, 

 adult female, enlarged. 



