186 INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



THE GLOOMY SCALE 



Chrysomphalus tenebricosus (Comstock) 

 (Aspidiotus tenebricosus Comstock) 



Description. — The scales of the adult females are circular, very con- 

 vex and dark gray being usually the color of the infested bark. The 

 surface is rough and the exuvias subcentral. The ventral scale is 

 well developed, dark around margins and light at the center. The 

 diameter of the scale is 1-19 inch. The female bodies are nearly 

 circular and amber-brown. The scales of the males are the same color 

 as the females but much smaller, oval, and with the exuviae at one end. 



Distribution.— This scale was reported by Alexander Craw as 

 injuring apple trees at San Jose, Santa Clara County, in 1891, 105 

 but has not been reported from other localities or from the same 

 locality in recent years. 



Food Plants.— The only host plants recorded are apple and maple. 



Control.— The control measures are the same as recommended for 

 San Jose scale. 



THE PURPLE SCALE 



Lepidosaphes beckii (Newman) 

 {Coccus beckii Newman) 



(Fig. 163) 



Description. — The female scales are elongated, oyster-shaped, often 

 slightly curved, from -^ to \ inch long and one third as wide. The 

 color varies from light brown to a rich reddish-purple. The male 

 scales are much smaller than the females, very narrow and with a 

 hinge near the posterior end to allow the matured winged male to 

 escape. The length of the male scale is about T V inch. The mature 

 male is light yellow and exceedingly minute. The eggs are slightly 

 oblong, very small and pearly white. 



Life History. — The eggs are deposited in the large egg-sac com- 

 posed of the female scale. These hatch in early summer (May to July) 

 and the young reach maturity in from four to six months. The species 

 is very prolific, there being several overlapping generations a year. 



Nature of Work.— This scale is a very serious pest and attacks all 

 portions of the host, including trunks, large and small limbs, leaves 

 and fruit. It may become so abundant as to hide the twigs and not 

 rarely to kill entire trees, unless control measures are employed. 



Distribution.— The purple scale is distributed throughout the coast 

 citrus belt of southern California, but is not present in a large number 

 of districts in this region. It also occurs in various places in the San 

 Joaquin and Sacramento valleys. 



Food Plants. — Banksia integrifolia, Cercidiphyllum japonicum, 

 citron, croton, eucalyptus, fig, grapefruit, lemon, Murray a exotica, oak, 

 olive, orange, Pomaderris apetala, silver thorn, hop-tree and yew 

 (Taxus cuspidata) are among the recorded food plants. 



Control. — This scale is very resistant to fumigation and a full dosage 

 of schedule No. 1 is required to control it. Small infestations have 



105 Destr. Ins., Cal. Bd. Hort, p. 11, 1891. 



