INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



177 



detus serratus, cherry, citron, clover, currant, Daphne gnidium, date 

 palms (Phoenix clactylifera and P. canariensis) , eucalyptus, fan palm 

 (Latania borbonica), ferns, Genista, grapefruit, grass, heath, holly, 

 English ivy, Kentia, lemon, madder, magnolia, manzanita, maple. 



Fig. 155. — The ivy or oleander scale, Aspidiotus hederw (Vail.). Greatly 

 enlarged. (After Quayle, Cal. Agrcl. Exp. Sta.) 



mistletoe, Monterey pine, mulberry, Myrsine retusa, nightshade, 

 oleander, olive," Opuntia littoralis, orange, pepper tree, plum, pome- 

 granate, holly oak (Quercus ilex), red-bud, redwood, sago palm, 

 sumach, umbrella plant, umbrella tree, Vitex littoralis, Vriesia splen- 

 dens and yucca are hosts. 



Control. — Control measures are the same as for San Jose scale. 



Natural Enemies.— Ladybird beetles and a small undetermined 

 chalcid parasite prey upon this scale. 



THE WALNUT SCALE 



Aspidiotus juglans-regiw Comstock 

 (Fig. 156) 



Description. — The female scales are light gray, nearly circular, with 

 yellow, pink or reddish-brown central or subcentral exuviae. The diam- 

 eter varies from ^ to -| inch. The bodies are yellow mottled with 

 orange spots, oval and distinctly segmented. The male scales are the 

 same color as the females, more elongated and about one third as large. 



Life History.— The life history is practically the same as for the 

 San Jose scale. 



12—13664 



