64 



CALIFORNIA STATE COMMISSION OF HORTICULTURE. 



While Australia has been credited as the home of this pest, later inves- 

 tigations seem to show China to be the real home. 



Chrysomphalus aurantii citrinus Coq. 

 (Yellow Scale of the Orange.) 



This species differs but slightly from C. aurantii, but in its habits 

 and color there is a very marked difference. The female scale is circular, 

 with the exuvise slightly to one side; the scale is not as convex; the 



FIG. 31. Chrysomphalus aurantii citrinus (Yellow Scale). On orange leaf. 

 Female, greatly enlarged. 



margins are wider and a light gray. The body is a pale yellow; the 

 ventral scale is light colored and remains attached to the upper one, 

 making it difficult to remove the insect from the scale. 



A curious fact about this insect is that it seldom attacks the wood, 

 even when the foliage and fruit are covered with them. On this account 

 the fruit-grower can readily determine between it and aurantii y as the 

 latter infests the young shoots and even the large branches. 



On orange and lemon. 



This scale was introduced into this State in 1872 and for a number 

 of years proved to be very destructive. It is now held in almost com- 

 plete subjection by its natural enemy, Aspidiotophagus citrinus Craw, a 

 minute chalcid fly introduced from Japan. 



