August, '22] BEYER: BEAN LEAF HOPPER 301 



Method of Control 

 The most difficult problem which was experienced regarding control 

 was the wide range of host plants of E. mali. Since rotation is out of 

 the question, and clean culture being of little value, after persuing a 

 series of spraying experiments it was concluded that equally as much 

 importance is to be attached to the method and kind of apparatus used as 

 upon the formula itself. Therefore, the writer has, after a series of 

 experiments, designed a sprayer attachment for truck crop insect control 

 work which rendered better results for Leaf -Hopper control than any 

 other available equipment which was first tested out with poor results. 

 The time when the spraying was started was found to be very impor- 

 tant as the Leaf -Hoppers attacked the plants as soon as they had formed 

 leaves. Since the Leaf-Hoppers attack the lower sides of the leaves 

 it would seem that only the lower sides would require an application of 

 spray. As a matter of fact it was observed after a number of spraying 

 experiments had been completed, where only the lower side of the leaves 

 were being sprayed, that often nymphs and also the adults, if they did 

 not take flight when molested, would assume their sidewise running 

 habit and pass over the margin of the leaf to the upper side of the leaf in 

 quest of protection and would later resume feeding when a suitable 

 place was found which had not been thoroughly sprayed. 



A New Spraying Device Designed by the Writer 

 This device contains three wide angle mist spray nozzles, all of which 

 are connected to a common hose which is attached to pressure pump 

 and sprayer tank. These nozzles are enclosed within a canvas covered 

 cylinder at least 36 inches in length and 24 inches in diameter. This 

 cylinder contains an opening 8 inches in width and running full length of 

 the cylinder. The opening is turned downward and serves as a passage 

 for the base of the plants, as the cylindrical enclosure enveloping the 

 plants passes over the row. A wide angle mist nozzle centrally located 

 in the top of this cylinder directs the spray downward on top of the foliage. 

 Two wide angle mist nozzles located, one on each side of the S-inch 

 opening and midway between the ends of the cylinder, which are adjust- 

 able to direct the spray either inward into the row of plants or upward, 

 thereby making it possible for the spray to make a thorough contact 

 with the lower side of the foliage. The ends of this cylinder are enclosed 

 with an adjustable iris curtain so that the aperature can be adjusted 

 according to the needs and the size of the plants. 



Some Advantages Over The Common Method 



1. It was found to prevent escape of insects when spray was applied 

 to the plants. 



