12 



FUMIGATIOX INVESTIGATIOiSrS IN CALIFOENIA. 



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 

 C o V i n 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. (0ri[;inal.) ,■[ • ii i, j. • 'j. • 



than m the hot ulterior 

 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 citiois 

 orchards. Even as far 

 inland as Ontario and 

 Riverside the black 

 scale is capable of 

 breeding freel}^ 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 rays. 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 l)lack scale (Saissetia 

 olese). (Original.) 



