THE CANADIAN ENTOMOLOGIST. 



NOTES ON THE LIFEHISTORY OF NEPTICULA SLINGER- 

 LANDELLA KEARFOTT (TINEID.^). 



BY C. R. CROSBY, ITHACA, N. Y. 



The following notes on the life history of the plum leaf-miner are 

 compiled from the notes of the late Professor M. Slingerland, supple- 

 mented by observations by the writer : — 



The plum leaf-miner is a new fruit pest which was brought to Pro- 

 fessor Slingerland's attention in the fall of 1907 by C. M. Hooker & Sons, 

 of Rochester, N. Y., who stated that it had been present in their plum 

 and prune orchards for a number of years and had been gradually 

 increasing in numbers. The mines were so abundant that the trees were 

 })artially defoliated and the size and quality of the crop injured. 



We have not been able to find this miner in other orchards, and with 

 the possible exception of apple no other food plant is known. That it 

 may occasionally attack apple is quite probable. While examining some 

 old apple trees in a neglected orchard, about a quarter of a mile from 

 the Hooker orchard, on July 7, 1911, the writer found that mines very 

 closely resembling those of the plum leaf-miner were abundant in the 

 leaves of the water sprouts growing at tlie base of several trees. Infested 

 leaves were brought to the insectary, but the larvae left the mines while in 

 transit and constructed cocoons indistinguishable from those of the plum 

 leaf-miner. The identity of this apple leaf-miner cannot be settled defin- 

 itely until the moths are reared next spring. 



In the Hooker orchard the plum leafminer has shown a decided 

 preference for certain varieties. German and Italian prunes are most 

 severely infested ; French and Shropshire Damsons are less subject to 

 attack, although some years ago the former variety was badly infested ; 

 Diamond, Bradshaw, Lombard and Rheinclaude are nearly immune. 



Life History. 

 The moth. — The adult of the plum leaf-miner is a small bronzy black 

 moth having an expanse of 1/7 to 15 inch. The fore wings are crossed 

 by a shining white band on the outer third and the head bears a con- 

 spicuous orange tuft. These moths emerge from cocoons at or near the 

 surface of the ground during the daytime in. the latter part of May and in 

 early June. During the day they remain quietly on the bark of the trunk 

 and larger branches, none being found on the leaves. Several hundred 

 moths are often found on a single tree ; when disturbed they suddenly 

 take flight and most of them settle on the opposite side of the tree. 

 They gradually decrease in numbers and about the middle of June 

 disappear. 



January, 1912 



