650 



STATE BOARD OP AGRICULTURE. 



Table II Effect of the Leafhopper EMPOASCA MALI on Potatoes 

 Greenhouse Experiments 1919* 



•Table reproduced from Kotila 8. 

 •*Sprouted tubers (1919 seed-stock) were potted on this date. 



Greenhouse Experiments - 1920-21 



30 E. mah nymphs 

 6 E. mali nymphs . 

 Check — no insects . 

 30 potato aphids. . 



Feb. 17 

 17 

 17 



17 



Burning, , , , 

 Burning , , , 

 No burning. 

 No burning. 



Injury noted February 23. 



From the results shown above it was demonstrated that the potato 

 leafhopper, Empoasca mali, is capable of producing injury to potato 

 leaves regai(lh\ss of the season or condition of light, and that aphids 

 do not have a similar effect. The burning produced in cages covered 

 with cheesecloth in the greenhouse during the month of February when 

 the light was very weak as compared to the strength of daylight during 



Fig. 3. Type of cage used in greenhouse experiments. 



