INSECTS INJURIOUS TO POTATOES AND TOMATOES 275 



The leaf hopper in question is a small insect of slender form, 

 about one-eighth inch in length. The adults have wings and are 

 also provided with hind legs fitted for hopping and are quite 

 active. The young hop to some extent but are much less active 

 than the adults. 



They winter usually as adults but are said also to pass the 

 winter in the egg stage, the eggs being laid in the fall on the food 

 plant. There are three or four generations. 



Injury to potato is of two kinds; first, the direct injury due 

 to the sucking of sap by the leafhopper and second, the blighting 

 of the leaves said to be caused by the leafhopper. There is some 

 doubt as yet as to just how much the leaf hoppers have to do 

 with the transmission of the disease which is called the tip-burn or 

 hopper-burn but Dr. Ball, (1. c.) has presented a very strong case 

 against the hopper. He maintains that the tipburn is the result 

 of a specific poison injected by the hoppers or a specific infection 

 carried by them. The evidence may not be quite conclusive 

 and is still the subject of investigation, but there are at least strong 

 probabilities that the case against the hoppers will be proven. 

 The problem is complicated by the fact that there may be more 

 than one kind of tipburn or tip blight, as a trouble of very similar 

 nature has been observed by the writer in fields where no leaf- 

 hoppers were to be found. This burn was generally ascribed 

 to weather conditions. 



Control. Control measures against this pest on potato have 

 not been very well worked out, but it is probable that clean culture 

 and spraying with nicotine preparations will be found to give 

 the best results. 



Tomato Worms 



The large green horn-worms which attack the foliage of the 

 tomato are the same as those previously described which attack 

 tobacco. Usually they are not so numerous but that they may 

 be readily controlled by handpicking, but if necessary the same 

 remedial measures may be used as advised for them on tobacco. 



The Tomato Fruitwonn 



The worms which commonly bore into the green and ripening 

 tomatoes are the same as the tobacco budworm and the cotton 



