326 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



THE EGGS OF EMPOASCA MALI LE B. 



By R. L. Webster, Ames, Iowa 



Last year, while connected with the Minnesota Experiment Station, 

 and doing some work with the apple leaf -hopper, Empoasca mali LeB., 

 I succeeded in finding a number of new facts regarding the life his- 

 tory of that species. During the present year, 1908, I have had some 

 opportunity to study the same insect at the Iowa station, and am able 

 to offer some additional data concerning the egg stage of this leaf- 

 hopper. The results of last year's work were given in a paper by 

 Prof. F, L. Washburn at the Chicago meeting of the Association of 

 Economic p]ntomologists, and were pul)lished in the April, 1908, num- 

 ber of the Journal of Economic Entomology. 



It is clear that the winter eggs, and those of the rest of the year, are 

 deposited in different parts of the tree. On young apple nursery 

 stock the eggs for the winter are deposited in the bark on the lower 

 portion of the trees, below the first branches, and form tiny pockets 

 or blisters on the bark. These egg blisters I found at Albert Lea, 

 Minnesota, May 20, 1907, on three-year-old apple stock at the Wedge 

 nursery. A young nymph was caught in the act of emerging from 

 one of these egg blisters, so there is no doubt of their identity. This 

 year I have found similar egg blisters on apple stock shipped to Ames 

 from Shenandoah, Iowa. 



In Minnesota last year Mr. George G. Ainslee found similar egg 

 pockets on an apple tree which at that time were supposed to be those 

 of Empoasca mali. These were much larger than the ones found by 

 myself at Albert Lea, and I now think that they were the eggs of some 

 Membracid which had oviposited in the bark of the apple tree. The 

 egg pocket found and described by Mr. Ainslee measured about 1 mm. 

 by 2 mm., much too large for a nymph, which is only .8 mm. long in 

 the first stage. Those egg pockets found by myself, which I know 

 certainly to be those of Empoasca mali, measured .4 mm. by .75 mm., 

 approximately. 



Mr. Ainslee found last year in September egg slits in the petioles 

 of apple leaves which he thought to be those of Empoasca mali. This 

 observation I have been able to corroborate during the past summer. 

 On July 17th, in the insectary, I noticed several young Empoasca of 

 the first nymphal stage dead on the petiole of an apple leaf, which had 

 been immersed in water for several days. On looking closely over 

 the petiole I found tiny slits in the epidermis near each one of the 

 dead hoppers. These were .6 mm. in length and were a long oval in 



