TREATMENT OF VINE HOPPERS 471 



season. The principal injury caused by this insect is due to the extrac- 

 tion of the plant juices. These are sucked out by means of a sharp 

 beak or proboscis, which is inserted into the plant tissues. 



A method of control practiced by some growers is the use of a 

 hopper cage in the early spring when the young shoots of the vine 

 are about four or five inches long. The hopper cage consists of a 

 framework of laths over which is tacked a double layer of mosquito 

 wire netting or a single 20-mesh wire screen. The bottom consists of 

 a shallow pan or tray made by turning up about an inch of the edges 

 of a sheet of light galvanized iron. One entire side of the cage is left 

 open, and there is a V-shaped opening in the tray at the bottom which 

 allows the cage to be pushed over the vine. The base of the V-shaped 

 opening in the bottom is padded with leather and the vine is bumped 

 and the hoppers jarred off, at the same time that the cage is being 

 swung into position. The sides of the cage and the tray at the bottom 

 are smeared with crude oil, and the hoppers as they are jarred off are 

 caught in the oil. 



If there is a breeze blowing the cage can be operated with the 

 open side facing the wind and practically no hoppers will escape. If, 

 however, the day is calm and warm and the hoppers are particularly 

 active a curtain can readily be dropped over the open side as the cage 

 is pushed on to the vine, and it will prevent any from escaping. 



The V-shaped opening which might allow hoppers to drop to the 

 ground in front of the vine can be covered with canvas, as follows : 

 Take two pieces of canvas about the shape of the opening and a little 

 wider. Double this once on itself and between the two layers sew in 

 pieces of three-fourths inch rubber tubing transversely. These are 

 then firmly tacked on the sides of the opening as shown in the engrav- 

 ing. This will allow the cage to be pushed in on the vine and the 

 flexibility of the tubing will bring the canvas immediately into position 

 again. This with the curtain in front, shuts off all possibility of escape. 



If catching the over-wintering hoppers is not practicable, the next 

 opportunity for effective work lies in killing the young insects, as 

 they appear from eggs placed in the leaf-tissue by these over-wintering 

 adults, before they get their wings. These young hoppers may be 

 killed by means of a spray applied to the under side of the leaves, and 

 this will be during May or the first part of June, depending upon the 

 season and locality. The exact time may be determined by watching 

 their development. When some of them have reached almost full 

 size it is time to start the spraying. The spray to use is the Standard 

 spray for thrips given on the preceding page. The spray should be 

 thoroughly applied from below so as to strike the under side of the 

 leaves, for the spray will kill only such hoppers as are hit. 



False Chinch-Bugs. Small, grayish-brown insects (about one- 

 eighth of an inch long when fully grown), which injure the vine 

 leaves. They drop to the ground when the vine is disturbed, and may 

 be caught as just described for vine hoppers. 



Grasshoppers. These pests often invade orchard and vineyard, 

 and sometimes kill the plants outright by completely defoliating them. 

 This plague has been successfully met by the use of the arsenic and 



