INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



153 



THE BLACK SCALE 



Saissetia olew (Bernard) 

 (Chermes olew Bernard) 



(Figs. 131, 132) 



Description. — The fully-matured females are black, nearly hemi- 

 spherical, hard scales with a distinct "H" upon the back, which 

 appears after they have become 

 one third or one half grown. 

 The average matured scale is 

 from ^ to ^ inch in diameter. 

 The male scales, which are rarely 

 observed, are very much smaller 

 than the females. They are 

 long, narrow, flat and nearly 

 transparent or colorless. The 

 adult males are light yellow and 

 exceedingly minute. The eggs 

 are nearly globular and yellow- 

 ish-brown in color. 



Life History The females 



deposit from fifty to three thou- 

 sand eggs, covering a period of 

 from two to four weeks. The 

 majority are laid during the 

 months of May, June and first 

 half of July, though in some sec- 

 tions all stages of the insect may 

 be found at nearly any season. 

 Young half -grown scales are 

 most abundant from September 

 15th to December 15th. The 

 insects work principally upon 

 the leaves of the trees, when they 

 are young, but later are found 

 almost wholly upon the limbs. 



Nature of Work.— All stages 

 may be found upon the leaves, 

 fruit and stems of the hosts, but 

 the latter appear to be preferred. 

 Upon some plants they may be 

 found at the base, several inches under the ground. Aside from 

 extracting the juices from the trees, the scales produce large amounts 

 of honey-dew, which, being a medium of growth for the black smut 

 fungus, causes the smutting of the fruit and foliage, which is by far 

 the greater injury. Because of this damage and its wide distribution 

 the black scale is generally conceded to be the most expensive pest in 

 the State. 



Distribution. — This scale is widely distributed throughout the citrus 

 growing sections of the southern and central parts of the State. It 

 also occurs in limited numbers in the northern part. 



Fig. 131. — Black scale, Saissetia olew 

 (Bern.). Immature and full-grown females 

 on oleander. (Original) 



