October, '12] CROSBY: BLACKBERRY LEAF-MIXER 403 



THE EGG OF THE BLACKBERRY LEAF-MINER 



Metellus ruhi Forbes (Scolioneura capitalis) 

 C. R. Crosby, Ithaca, N. Y. 



Prof. C. 0. Houghton has recentlj'^ pubHshed an excellent account 

 of the Blackberry Leaf-miner (Del. Agr. Exp. Sta. Bull. 87. 1910) 

 but states that he has not observed the egg. The following note is pre- 

 sented to help fill this break in our knowledge of the life-history of 

 the insect. 



On August 25, 1908, the writer visited a large field of dewberries at 

 Ripley, N. Y., which earlier in the season had been rather severely 

 infested. The larvae of the second brood were just beginning their 

 mines. A careful examination of the under side of the leaves showed 

 that the mines usually start near a prominent vein and that at their 

 base a small round blister is present. These blisters are about .75 mm, 

 in diameter, nearly round, low, green in color, and have a smooth 

 surface. They are usually found close to a prominent vein and two 

 are often placed close together. The egg itself is nearly white, smooth, 

 flattened and lies between the two layers of the leaf. Plate 10, fig. 1 

 shows one of the blisters intact; the other has been opened and the 

 egg partly removed. The blisters are rather inconspicuous but after 

 one becomes used to looking for them can be easily detected without 

 the aid of a lens. 



According to the observations of Professor Houghton the eggs are 

 probably inserted into the leaf from the upper side (Ent. News, XIX, 

 p. 213. 1908) 



Fall Army Worm {Laphygma frugiperda Sm. & Abb.)- This insect was excep- 

 tionally abundant the latter part of September and early October in lawns and 

 fields in the vicinity of New York city and on the eastern extremity of Long Island. 

 There were several complaints of serious injm-y to lawiis, the parties reporting the 

 gi'ass to be so seriously affected that they were fearful it would be destroyed. The 

 caterpillars were reported very injurious to corn on Long Island. The larvae, as 

 is characteristic of this species, vary greatly in coloration. This outbreak is un- 

 usual for New York state or else, owing to the lateness of the season when the pest 

 is usually abundant, is generally overlooked. 



E. P. Felt. 



