April, '081 



JOURNAL OP ECONOMIC ENTOMOLOGY 



143 



with a membranous and semi-opaque shell, and 1.5 mm. long. He 

 says in his report : ' ' The cavity was lined with a reddish, glossy ma- 

 terial, which seemed to be a thin skin, separable from the woody tis- 

 sues. The sap was just beginning to 

 run and the tissues were full of it. " 



Of course, it yet remained to be 

 proven that the above egg was that of 

 Empoasca. No more eggs were found 

 until May 24th, when Mr. R. L. Web- 

 ster, in charge of the insectary and a 

 part of the field work for the depart- 

 ]nent during the summer, found them 

 quite numerous in three-year old 

 apple stock in a southern Minnesota 

 nursery. He reports these eggs as ^ ' "' 



being somewhat smaller than those 

 found at St. Anthony Park, measur- 

 in"' 4 and .75 nun. Mr. Ainslie's de- fig.6. Nymph of £i>iportscn«io(i within 



^ ,. 11 ^ iU 1 ^- the pouch, the covering epidermis t)einK 



SCriptlOn applies so well to the later turned back, much enlarged (ongmai). 



found eggs that there is but little if 



any doubt of their being those of the same species. All these "blis- 

 ters" or pouches containing eggs were found on old wood in the 

 upper part of the trunk, and none on the small twigs, and their 

 general shape varied from that of a fresh water mussel or clam shell 

 to almost cylindrical. 



A small tree showing a number of these blisters was taken into the 

 insectary, and there a young Empoasca was observed in the act of 

 emerging. This specimen died before becoming free from the blister. 

 A sketch was made at the time by our artist, showing the bark cut back 

 and the body of the larva below. 



We cannot speak of the location of the summer egg with as much 

 certainty as we can of the winter egg, although putting the evidence m 

 our possession with that of others, we are inclined to the belief that 

 the petiole and mid-rib, as well as the leaf itself, may be the places 

 chosen for oviposition on the apple by the females of the summer gen- 

 erations, for Ainslie found on June 25th an enlargement on a petiole 

 which contained the remnant of an egg shell, and on September 4th 

 Webster found a swelling in a leaf similar to that which character- 

 ized the presence of the winter eggs. Only one was found. Webster 

 describes it as 5 mm. long, slightly brown, with a slit in one end. 



On September 19th in a large nursery, Mr. Ainslie examined a num- 

 ber of one year old apple trees. These trees were almost hidden in a 



N. B.— Insert iu place of pages 143. 144. 



