INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



359 



Food Plants.— The principal food in California is the fruit of the 

 cherry. Professor W. T. Clarke also reports finding eggs in the calyces 

 of plum trees. 259 In Oregon, P. J. O'Gara has found the insect more 

 destructive to prunes and plums than to cherries. He also records as 

 hosts apricots, sweet and sour cherries and peaches. 



Control. — Two or three applications of arsenate of lead, 4 to 5 

 pounds to 100 gallons of water, usually suffice to control the pest. The 

 first spraying should be made shortly before the blossoms open, and 

 the second about ten days later, when the petals have practically all 

 fallen. If necessary, a third application should be made in about 



Pig. 355.— The cherry fruit sawfly, Hoplocamiia cookei (Clarke), o, egg; b, posi- 

 tion of egg in the blossom ; c, larva ; d, adult female ; e, saw of the female's ovipositor : 

 f, serrations on saw; g, sheath of the saw; h, head of adult, front view; i, infested 

 cherries showing larva inside and exit and entrance holes, a, c, d, e, f, g and h, 

 greatly enlarged; b and i, slightly enlarged. (After Foster, U. S. Dept. Agric. ) 



another week's time. The first spraying is to kill the first hatched 

 larvas as they enter the very small fruits, and the second and third are 

 to prevent them from entering other fruits. 



Several thorough cultivations, just after picking time or during the 

 fall, has been suggested as a means of destroying many of the pupa? 

 in the soil. 



Natural Enemies. — Two undetermined internal hymenopterous 

 parasites were reared from this insect by Mr. Foster. Perhaps the 

 parasites are responsible for the slow spread and the spasmodic work 

 at intervals of several years. 



2S9 Can. Ent. XXXVIII, p. 351, 1906. 



