12 
FUMIGATION INVESTIGATIONS IN CALIFORNIA. 
and Ventura counties; in Los Angeles County, inward from the coast 
as far as Hollywood and Whittier, and in the lower part of the 
San Gabriel Valley at 
Covin a and Duarte; 
throughout Orange 
County; and in San 
Diego County in the 
region about San 
Diego city. This insect 
confines its attack to 
citrus trees. 
The black scale (fig. 
4) is also considered as 
partial to the more 
moist regions, and with- 
out doubt is able to 
mature more freely here 
Fig. 3.— Fruit of orange infested with purple scale. (Oridnal.) n ,-i r ,. • , 
than in the hot interior 
country. It is distributed, however, throughout the citrus-growing 
localities with the exception of the Rialto-Highland-Redlands region 
of San Bernardino County. At Redlands this scale is found on olives 
and some ornamental 
plants; yet, to the best 
of the writer's knowl- 
edge, it has not been 
reported from citrus 
orchards. Even as far 
inland as Ontario and 
Riverside the black 
scale is capable of 
breeding freely during 
some parts of the year, 
but the hot days of 
summer destroy a 
large percentage of the 
eggs and especially 
those young scales 
which are exposed to 
the sun's ra} r s. This 
destruction was espe- 
cially noticeable in the 
summer season of 
1907, when the writer 
was engaged in an examination of different localities. During the 
first part of July occurred a few days of very hot weather. About 
Fig. 4.— Branches of orange infested with black scale (Saisxttia 
olex). (Original.) 
