44 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 



of the most characteristic markings to be found among the scale in- 

 sects, consisting of a very plain elevated letter "H" upon the backs 

 of both the young and old females. The male scales, which are much 

 smaller than the females, are usually entirely wanting and when pres- 

 ent appears as very thin, transparently white exuviae, from which the 

 males, after undergoing transformation, emerge as tiny two-winged 

 insects. This occurs when the females are about one-third or half 



Fig. 1 



Fig. 2 



Fig. 1. The black scale, Saissetia oleae (Bern.). The young females as they 



appear on the olive leaves and twigs during the winter months. (Original). 

 Fig. 2. Adult females of the black scale, Saissetia oleae (Bern.), on an olive twig. 



(Original.) 



(Photos by Div. Sci. Illust., Univ. Calif.) 



grown. After mating, the males die, and so it is that even when 

 present, because of their small size, entirely different form, and short 

 life, they are not generally known to the orchardists. The females, 

 however, are always in evidence, and do the damage to the trees. 

 They reach maturity in most localities during the months of June, 

 July and August and lay from 100 to 3000 small oblong or oval 

 whitish or amble-colored eggs which remain beneath the large, nearly 

 hemispherical hollow body, the underside of which shrivels as the 



