10 



FUMIGATION INVESTIGATIONS IN CALIFOENIA. 



EXTENT OF CITRUS ORCHAIIDS." 



The production of citrus fiiiits in southern CaHfornia is confined 

 to the narrow stretch of land south and west of the Sierra Madre 

 Range, extending from Santa Barbara on the nortli to the Mexican 

 border. Altliough citrus plantings are located here and there through- 

 out this territory, in reality only a small proportion of the land 

 capable of cultivation is devoted to this industiy. The most promi- 

 nent centers of production (see fig. 1) are in the foothills region and 

 lower land of the San Gabriel Valley; the corresponding regions of 

 the San Bernardino Valley, including the Redlands-Highland, the 

 Riverside, and the Corona districts; and the coast region of Orange 



ANGELES 





SAN BERNARDINO 



ORIVtHSIDE 

 °/)f>LINGTOH 



RIVERSIDE 



o£sco/i/e/oc 

 SAN OIEGO 



0l/lfC£S/0£ 



MN D/E60 

 OCHULA VISTA 



Fig. 1.— Map showing principal localities in southern California where citras fruits are produced. 



(Original.) 



and Los Angeles counties. Regions of smaller production are found 

 in southern Santa Barbara and Ventura counties, in the San Fer- 

 nando Valley, and in western San Diego County. 



CITRUS PESTS. 



INSECT ENEMIES OF CITRUS FRUITS, AND THEIR DISTRIBUTION. 



The larger number of the pests most injurious to citrus fruits in 

 southern California belong to the Coccidse, a group of insects popu- 

 larly known as scale-insects. Among the scale-insects which are 



a For a general description of the California citrus-fruit industry, see Bulletin 123, 

 Bureau of Plant Industry, United States Department of Agriculture, which may be 

 obtained for 20 cents from the Superintendent of Documents, Government Printing 

 Office, Washington, D. C. 



