LEAF HOPPERS INJURIOUS TO CEREAL AND FORAGE CROPS 31 



fields where recent planting or clean culture was the rule. The hop- 

 perdozer treatment would probably serve in places where it can be 

 used. 



THE POTATO LEAF HOPPER 



The potato leaf hopper, Empoasca fdbae Harris, was first de- 

 scribed by Harris, presumably from beans, later by LeBaron as a pest 

 of apple, and it has received considerable attention at various times 

 in this connection and as a pest of various woody plants. It is also 

 at times very destructive to other crops, having been noted on pota- 

 toes, beans, soybeans, cowpeas, alfalfa, clover, etc., by various authors. 

 It is credited with causing the injury known as hopperburn in pota- 

 toes, and has been reported as attacking the second crop of alfalfa, 

 causing it to turn yellow. Various records show a ready adapta- 

 bility to alfalfa, and indicate that the species must be reckoned with 

 in the growing of this crop. 



Figure 12. — The five nymphal stages of Empoasca faoae, X15. (After Webster) 



The insect is about one-eighth inch in length, of a light grass-green 

 color, usually quite brilliant and sometimes iridescent, this color 

 prevailing throughout the entire body, but there is a series of whitish 

 spots along the front margin of the prothorax, usually six of them, 

 and two whitish lines or stripes on the mesothorax which are united 

 near the center by a transverse band, forming the letter " H." A 

 small triangular white spot occurs on the scutellum, with a small dot 

 on either side. The eyes are brilliant white when the insect is alive, 

 but turn a dull brown in dried specimens. 



THE NYMPHAL STAGES 



The nymphs (fig. 12) are light green, often with a yellowish tinge, 

 and are found usually upon the underside of the leaves of the plant 

 which they infest, clustered commonly beside the midrib and main 

 ribs, where they suck the juices of the leaf. 



DISTKIBUTTON 



The species is widely distributed over a considerable part of the 

 United States, but it has been determined by De Long that records 

 west of the Plains region are to be referred to another species. 



