THE MONTHLY BULLETIN. 



129 



Pinus radiata, pomegranate, buckthorn, sumach, redwood {Sequoia sem- 

 pervirens), nightshade, California laurel {Umhellularia calif ornica) . 



Control. — Same as for San Jose scale. 



Natural Enemy. — A small chalcid parasite works effectively upon 

 this scale. 



THE ENGLISH WALNUT SCALE. 



Aspidiotus juglans-regiw Comst. 

 (Fig. 112.) 



General Appearance. — Scales grayish to brownish, circular with 

 exuvi^ near one side. The position of the first 

 skin is marked by a pink or reddish brown 

 prominence. Body is yellow ; diameter of shell 

 one sixteenth of an inch. The male scale is 

 elongated, the same color as the female, and 

 one third as large. 



Life History. — The young settle on the ten- 

 der shoots or tough bark on the trunks and 

 limbs. The adults secrete themselves so closely 

 to the bark as to be almost hidden. In many 

 cases they appear to mine into it. 



Distribution. — Throughout the southern 

 part of the State in limited numbers, but has 

 never become a serious pest. Taken by the 

 writer in Ventura County, but found only on 

 Cottonwood trees there. 



Food Plants. — English walnut, cottonwood, 

 locust, pear and cherry. 



Control. — Lime sulphur (1-9) during the 

 winter months will easily control this scale. 



Fig. 112. — English walnut 

 scale (Aspidiotus juglans- 

 reffice Comst.). (Original.) 



THE PERNICIOUS OR SAN JOSE SCALE. 



Aspidiotus perniciosus Comst. 

 (Figs. 113, 114.) 



General Appearance. — The female scales are circular, light gray 

 and less than one eighth of an inch in diameter. The body is yellow. 

 The male scale is much smaller than the female, somewhat longer, and 

 of the same color. The males are very delicate pink insects with two 

 frail wings. 



8— H 



