REPORT OF THE SOCIETY 69 



in a period of two dry hot, weeks so that a "burned over" appearance is given 

 to the crop. Usually, however, the upper, young parts of the plants escape 

 burning for a time owing to the fact that the adult females prefer young grow- 

 ing tissues for oviposition. It is not until the eggs hatch and the nymphs begin to 

 feed that injurv is noticeable in these parts. The nymphs, because they do not 

 migrate rapidly, are restricted in their feeding to the area in which they were 

 hatched, consequently causing severe injury in that area. Adults, on the other 

 hand, fly at the shghtest disturbance and thus their effect is more distributed. 

 During cool moist weather the burning is checked and this also applies to 

 plants which have been sprayed with Bordeaux. 



Effect on Plant 



The eggs are laid on the midrib and petiole of the potato leaf and when 

 hatched the nymphs feed mostly by sucking juice from the larger veins in the 

 upper part of each leaflet. This reduces the supply of sap for the smaller veins 

 at the margin and tip of the leaflets and accounts for the fact that browning, 

 rolling and drying out occur at the tip and margin. There is thus a direct loss 

 of sap from the leaves followed by the death of large areas of leaf tissue. This 

 occurs at the time when maximum growth rate of tubers should occur. Con- 

 sequently the tubers suffer and the greater the area of foliage affected the 

 more severe the effect on the tubers. In cases where defoliation is complete, 

 or nearly so, the crop is a total loss. 



Other Hosts 



Field observations show that this insect may live temporaril3^ on many 

 hosts among which are: bean, apple, beet, rhubarb, raspberry, red clover, Swiss 

 chard, strawberry, cucumber, lettuce, dahlia, hollyhock, elm, box-elder, bur- 

 dock, rose, etc. 



On some of the above the leaf-hopper merely feeds, but on beet, apple, beans 

 and box-elder it will also reproduce. 



Life History 



The potato leaf hopper (E. Mali) lives over winter in the adult stage in pro- 

 tected places such as among thickly growing weeds, in brush, etc. In June 

 they come out from their resting place and feed for ten days or so on the apple 

 and other trees and shrubs, and at this time females predominate. At the end 



