140 



INJURIOUS \M> BENEFICIAL INSECTS OF CALIFORNIA. 



existence but when half-grown or over they seldom move unless com- 

 pelled to do so by lack of food. In greenhouses the broods are over- 

 lapping, but there is usually but one or two a year. 



Nature of Work. — All stages are to be found upon the leaves and 

 stems of the hosts, but the species does not seem to be prolific enough 

 in this State to do serious harm. 



Fig. 119. — The tessellated or palm scale. Eucalumnatus tes- 

 selldtus (Sign.), on palm leaves. Slightly enlarged. Collected 

 at San Francisco by B. B. Whitney. (Original) 



Distribution. — This scale is very commonly found in nurseries,, 

 greenhouses and private gardens throughout the State and is often 

 taken in quarantine from other states and countries. 



Food Plants. — The following plants are known to be subject to 

 the attacks of the tessellated or palm scale : betel nut, fish-tail palm, 

 wine palm, cinnamon, coconut, coffee, jambos, Howea belmoreana, 

 Kentia spp., laurel, orchids, rattan palm, Rhapis fldbelliformis, seaside 

 grape and fortune's palm. 



Control. — Spraying with carbolic acid, kerosene or distillate emul- 

 sions are recommended. In treating tender greenhouse plants these 

 sprays should be diluted considerably to prevent injury. 



THE GRAY CITRUS SCALE 



Coccus citricola CampbelP 

 (Figs. 120, 121) 



Description. — The mature females are fiat or slightly convex ana 

 regularly oval. They are larger than the soft brown scale, the largest 

 ones being slightly more than \ inch long, while the average length is 



"This scale was first discovered by the writer in 1909 al Claremont, Cal. It was 

 then thought to be Coccus longulus (Dougl. ), and a short article on the species under 

 that name was published in the Pomona College Journal of Entomology, Vol. I, 

 pp. 31-32, 1909. This gave rise to the common name, "longulus scale." which is 

 now a misnomer and which the writer has changed to the "gray citrus scale." The 

 »r> me "false soft brown scale" is not applicable, as there is a Coccus pseudohesperidum 



