INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 135 



is passed in a somewhat dormant half-grown condition. When the 

 leaves and fruit appear in the spring a large number of the hibernating 

 forms move upon them so that the leaves are often generally and the 

 fruit occasionally infested with the nearly or fully-matured females. 

 There appears to be but a single rather drawn-out brood a year. 



Nature of Work.— This scale feeds upon the leaves, bark and fruit, 

 producing considerable honey-dew. It has not, however, proved to be 

 a pest of any importance in the State so far. 



Distribution.— The fruit-tree Pulvinaria had not been known to 

 exist in the State before 1910, when it was collected in Los Angeles 

 County by C. H. Vary. It has since been taken in considerable num- 

 bers in Yolo and Tehama counties, being more abundant at Corning, in 

 the latter county, than in any other locality in the State. 



Food Plants.— As the common name implies this is a fruit-tree pest, 

 having been recorded only on apple, peach, plum and prune trees. 

 The prune is the preferred host in California. 



Control. — So far control measures have been unnecessary. In case, 

 however, that it should become a pest of economic importance the 

 treatment as recommended for the European fruit Lecanium, employed 

 in the winter when the scale is in the half-grown condition, will doubt- 

 less give the desired results. 



COTTONY MAPLE OR VINE SCALE 



Pulvinaria vitis (Linnaeus) 



{Coccus vitis Linnseus) 



[Pulvinaria iftnumerahilis (Rathvon)] 



(Fig. 115) 



Description. — The bodies of the females are rather flat, oblong m 

 shape and yellowish or dark brown in color. The egg-sac. which is 

 secreted posteriorly, is composed of a fine, white, cottony material 

 oblong in shape and from two to three times as long as the body. The 

 egg-sac and body together are about { inch long. The eggs are very 

 small, oval and from white to yellow in color. 



Life History. — The eggs are deposited in the large, loose, cottony 

 sacs, which are secreted by the females. The young settle on the 

 leaves and smaller limbs. The males appear late in the fall to mate and 

 die. In the spring the females increase very rapidly and after egg- 

 laying shrivel and die. There is but one generation a year. 



Nature of Work. — During the summer the young may be found upon 

 the leaves and tender twigs. When the leaves begin to harden and 

 fall in the autumn the young scale moves to the younger twigs, where 

 they remain throughout the winter and where nearly all reach maturity. 

 In the spring, however, when the leaves appear a few move again to 

 them, where they remain until full-grown. Serious infestations greal Ly 

 lessen the vitality of the trees and the large amount of honey-dew 

 makes them very unsightly. 



Distribution.— This scale, though seldom as troublesome in this 

 State as in the Eastern states is quite widely distributed. 



Food Plants. — The following plants are attacked: alder, apple, 

 beech, blackberry, box-elder, boxwood, buckeye {^Esculus flava) , cur- 



