142 



[NJURIOUS AMi BENEFICIAL INSECTS OP CALIFORNIA. 



Food Plants.— Grapefruit, lemon and orange trees are attacked by 

 this scale. Other species of Citrus will undoubtedly also become 

 infested as opportunity is afforded. Nightshade growing under or 



near citrus trees is also sometimes infested. 



Fig. 121. — The gray citrus stale. Coccus citricola Campbell. Full-grown females 

 on orange twigs. Enlarged three times. (Original) 



Control. — Fumigation is apparently the best method of control and 

 should be done as soon after all the young are hatched as possible. 

 In the southern part of the State fumigation with one half to three 

 fourths schedule Xo. 1, during the time from July 15th to August 15th, 

 has given the best results. In Tulare County fumigation with the same 

 dosage gave equally good results as late as November. Spraying with 

 oil emulsions and commercial oil sprays has also given good results and 

 is recommended when fumigation is not possible or in conjunction with 

 fumigation. 



