38 STORRS AGRICULTURAL EXPERIMENT STATION 
APPLE LEAF-MINER.* 
(Tischeria malifoliella Clemens.) 
_ ORDER, LEPIDOPTERA ; FAMILY, TINEIDAE. 
Many fruit-growers have observed small, brownish patches 
on the leaves of apple trees. These patches are caused by a 
minute insect which feeds on the internal tissue of the leaf. 
The insect has not been regarded as a serious pest, but during 
the past season it has occurred in sufficient numbers in many 
sections of New England to cause apprehension on the part 
of fruit-growers. Our attention was first called to it during 
the month of July, when the foliage of several trees of the Col- 
lege orchard were observed to be peculiarly affected. At first 
the injury was thought to be due to spraying, but closer ex- 
amination revealed the true cause of the trouble. 
Later in the season several inquiries, especially from the 
northern part of the state, were received in regard to an “un- 
known apple-tree pest,” which proved to be the Leaf Miner. 
As the outbreak appeared to be of sufficient extent to cause 
serious loss to the fruit-growing interests of the state, and as 
the insect is likely to become a well established pest of the 
apple orchard, we decided to make a study of its life-history 
with a view of discovering some vulnerable period in its 
existence. Asa result of these observations we believe that we 
are able to present a more accurate description of the insect 
in its various stages than has previously appeared. At this 
time, however, we are unable to give any further information 
in regard to the methods of controlling the insect. This bul- 
letin, therefore, is for the purpose of calling the attention of 
the apple-growers to this new pest and to give them the best 
known method of keeping it in check. 
*The Trumpet Miner of the Apple, Brunn, Second Report (1883), 
Cornell Agr. Exp. Sta, p. 155. The Apple Tischeria, 15th Rept. State 
Ent. Ill., p. 45 (1889). 
