12 BULLETIN" 419^ U. S. DEPAETMEN-T OF AGEICULTUEE. 



of a larva of the grape leaf-folder. These eggs hatched the following 

 day, and the active little parasites greedily attacked their host, feed- 

 ing externally, their mouth parts embedded in the soft tissues. In 

 five days they left the remains and pupated. The pupse at first were 

 milk white, but later turned black. These pupse overwintered in 

 jars, and on May 30 of the following spring the adults issued (fig. 4, d). 



Habrohracon johannseni Vier. (PI. IV, a-f), a new species of 

 braconid, was found widely distributed. It feeds externally upon 

 the Desmia larvse. 



The fly parasites of the grape leaf-folder were taken only in small 

 numbers. The most abundant of the three species was the tach- 

 inid ExoHsta pyste Walker (PI. IV, g) . 



METHODS OF CONTROL. 



Vineyards regularly sprayed with arsenicals for the control of the 

 grape rootworm, grape-berry moth, etc., will be practically free 

 from injury by the grape leaf-folder. The insect is especially likely 

 to cause injury in small vineyards not regularly sprayed and to 

 grapes grown in arbors in backyards and similar places. 



Where the insect has been troublesome in previous years, the 

 vines should be weU sprayed with arsenate of lead at the rate of 

 2 pounds of the paste or 1 poimd of the powdered article to 50 

 gallons of water, shortly after the blossoms have fallen. One treat- 

 ment at this time, if thoroughly made, should destroy the caterpillars 

 of the first brood so effectually that injury by second-brood larvae 

 would be of little importance. If the caterpillars continue trouble- 

 some, however, additional applications should be made. Arsenicals 

 are usually applied to grapes in fungicides, as in Bordeaux mix- 

 ture for the control of fungous diseases. Information on the general 

 subject of spraying grapes is contained in Farmers' Bulletin 284, 

 United States Department of Agriculture. For small spraying oper- 

 ations, as in back yards, a Yerj simple spraying outfit may be em- 

 ployed, such as a bucket pump or knapsack pump. 



Where it is impracticable to spray the vines, it will be decidedly 

 advantageous to go thoroughly over the plants when the folded 

 leaves are in evidence and crush the larvae by hand. As an addi- 

 tional method of reducing injury it is advisable to rake together 

 and burn fallen fohage in the fall, since the insect passes the winter 

 in the pupal condition in these leaves. 



