288 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



the lower and upper epidermis of the leaves. Probably in about ten 

 days to two weeks the larvae complete their work as miners and begin 

 constructing oval cases which they cut out of their mines in the leaves. 

 The larvae live as case-bearers during July, August, and September 

 falling with the leaves and changing to pupae within their cases. 

 Here among the fallen foliage the pupae remain until the following 

 spring. There is thus but one generation each year. 



Methods of Control 



Trees standing in a pasture where the leaves are blown away even 

 though they were only a few rods from a badly infested woodland 

 were scarcely touched by the insect. This suggests that if the leaves 

 were raked in piles and burned or otherwise destroyed the pest could 

 be held in check. This, of course, would entail considerable time and 

 labor but if well done for once only the pest would be effectively check- 

 ed for several years. 



The only other feasible control consists of a thorough dusting of a 

 grove with arsenate of lead by means of an airplane which now seems 

 to be within reasonable possibiHty. 



References 



1856. Fitch, Asa. Second Rept. Nox. Ben. Ins. N. Y., p. 269-273. 



1885. Fletcher, James. Rept. of the Ent., Dept. Agri. Can., p. 14. 



1903. Comstock, Anna B. Ways of the Six-footed. Ginn & Co., p. 29. 



1912. Felt, E. P. 27th. Rept. State Ent. N. Y., p. 56-59. 



ARTIFICIAL PRODUCTION OF HOPPERBURN 



By F. A. Fenton and I. L. Ressler 

 Iowa State College, Ames, Iowa 



While there have been ntimerous tests m.ade which have shown that 

 Empoasca malt LeB is capable of producing hopperburn when placed on 

 potato leaves, yet there has been comparatively little done in the way of in- 

 oculation tests with this insect. The writers conducted experiments 

 during the past summer in order to observe the effects of the injection 

 of leafhopper extract and of dilute poisons into the leaf tissue as well 

 as to test out further the results of multilation of potato leaves, and 

 were able to secure interesting data which may help toward the 

 ultimate solution of this problem. Potato leaves were mutilated 

 with various instruments, inoculated with dilute acid and alkali, and 

 with water in which mali adults, nymphs or hopperburned tissue had 

 been macerated. Also further tests were made in which these insects 



