INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



357 



Food Plants.— The cherry and pear are the preferred host plants, 

 but buttonbush, hawthorn, Juneberry, mountain ash, plum and quince 

 are also attacked. 



Control. — This is one of the easiest pests to control. The larvae 

 readily succumb to the ordinary soap or emulsion sprays and may be 

 effectually destroyed by blowing dust 

 upon the infested leaves. A spray 

 composed of 2 pounds lead arsenate 

 to 50 gallons of water is also very effi- 

 cient in controlling it. 



Natural Enemies.— Without doubt 

 the reason for this pest's not becom- 

 ing more serious in California is due 

 to the natural enemies which hold it 

 in check. In this State these enemies 

 have never been recorded, but in the 

 Middle States the egg parasites, 

 Trichogramma minutum Riley and 

 Closterocerus cinctipennis Ash., are 

 quite common. 



There are probably also parasites 

 working on the larva;. This, however, 

 has never been definitely ascertained. 

 The spined soldier-bug, Podisus macu- 

 liventris Say, and the rapacious sol- 

 dier-bug, Sinea diadema Fab., are 

 active enemies of the larva 3 and adults. The larvae of the green lace- 

 wing also devour many of the young. Both of the last two insects 

 occur in California. Hot weather also reduces the numbers. 



Fig. 353. — Larvae of the pear or 

 cherry slug and their work on a pear 

 leaf. Natural size. (Original) 



THE CHERRY FRUIT SAWFLY^ 



Hoplocampa cookci (Clarke) (Family Doleridse) 



(Dolerus cookci Clarke) 



(Hoplocampa calif or nica Rohwer) 



(Figs. 354, 355) 



Description.— The adults are mostly black, with light reddish-brown 



or yellowish legs and antenna?. A portion of the head is also reddish. 

 The females are about 1-9 inch long and the males | inch long. They 

 have four well-developed wings and their general appearance is well 

 shown in Fig. 355. The eggs are whitish, shiny, somewhat kidney 

 shaped and about 1-50 inch long and 1-75 inch wide. The full-grown 

 larva? are yellowish-white, with the head, tip of abdomen and legs 

 darker yellow and the eyes black. They have three pairs of well-devel- 

 oped legs near the head, six pairs of small prolegs behind these and one 

 pair of prolegs at the posterior end of the body. The body is usually 

 curved in the shape of a crescent and is distinctly segmented and 

 wrinkled. At first the pupae are the same color as the larvae and grad- 

 ually assume the color of the adult as maturity is reached. 



Life History. — According to Foster 258 the females appear in tin- 

 spring, just about the time the Black Tartarian cherries are beginning 



""Foster, S. W., Bui. No. 116, pt. III. Bur. Ent. U. S. Dept. Agric, 1913. 

 Mo. Bui. Cal. Hort. Com. Ill, pp. 31-35, 1914. 



