232 CITRUS FRUITS AND THEIR CULTURE. 



say that conditions are nearly equalized throughout the 

 country. Regions which are free from one pest generally 

 have another equally troublesome. No one section can 

 expect to long remain free from their inroads. Still some 

 climatic conditions appear to be more favorable for the 

 development of some insects than others. The black scale 

 of citrus trees is a great pest in the coast regions of Cali- 

 fornia, while farther inland it is not so troublesome. 



