192 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



Distribution.— As this pest is confined to the date growing sections 

 of the State, it is found only in the southern part, and more particu- 

 larly in Riverside and Imperial counties. 



Food Plant. — So far as known, this scale feeds only upon the com- 

 mercial varieties of the date palm. 



Control. — Removing all of the branches and burning over the entire 

 trunks of the palm trees with a gasoline torch has proven, according 

 to Professor R. H. Forbes, 109 to be an effective remedy for this scale. 

 The remedies given under the Marlatt scale, Phcenicococcus marlatti 

 Ckll. are also used for this insect. 



Natural Enemies.— The principal enemies of this pest are the larvae 

 of the ashy-gray ladybird beetle (Olla abdominalis) , Chilocorus cacti 

 and Scymnus sp. Internal parasites do very little to check it; in fact, 



none of the natural enemies play 

 an important part in its control. 



THE CHAFF SCALE 



Parlatoria pergandii Comstock 110 



(Figs. 168, 169) 



Description. — The female scales 

 are small, irregular, nearly circu- 

 lar or slightly elongated, dirty- 

 gray in color, with the exuviae 

 near one end. The male scales 

 are decidedly longer than broad, 

 light gray with the lateral mar- 

 gins prominent. 



Life History.— This is quite a 

 prolific species, which has not 

 gained any considerable foothold 

 in California. Breeding continues 

 throughout the year in the south- 

 ern part, there being several 

 broods annually. 



Nature of Work. — The scale 

 collects in great numbers upon 

 the trunks, large and small limbs, 

 leaves and fruit of the trees and 

 greatly reduces the vitality and 

 causes the leaves to turn yellow 

 and drop. 



Distribution. — This species is 

 limited to only a few localities in 

 the State. It was first shown to 

 the writer by C. H. Vary at 

 Pomona and was later found at Ventura. A. S. Hoyt reports it from 



Fig. 16S. — The chaff scale, Parlatoria 

 pergandii Comst., on orange leaf. En- 

 larged twice. (Original) 



108 Jr. Ec. Ent, VI, pp. 415-416, 1913. 



"°A variety, Parlatoria pergandii cametli<e Comst., has been taken on camellia at 

 Sacramento. Fig. 169. 



