284 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



N. Y., where it is abiindant and injurious in a large sugar-bush and 

 near South Colton, West Pierrpont, De Grasse, and Russell in St. 

 Lawrence Co. in all of which localities it is seriously injurious. Felt 

 has recorded it as abundant and injurious near Bolton, N . Y. It is prob- 

 ably widely distributed throughout the Adirondack region. 



The author has never found the larvae on anything but the sugar 

 maple although I have reared them to maturity on the red maple (A 

 rubrum). Fletcher (1884) records the larvae feeding on the foliage 

 of beech trees growing among infested maple trees after the foliage 

 of the latter had been devoured. 



T.he first indication of the presence of the insect in a grove is dur- 

 ing the first half of June when t.he leaves begin to lighten in color ow- 

 ing to the multitudes of tiny blotch mines in which the young larvae 

 have already eaten out the green tissues. The effect on the leaf at 

 this time is certainly more serious than has been suspected. As many 

 as 116 mines were counted in a single leaf in which a large part of the 

 green tissues had been destroyed. After the mining period, which 

 probably occupies about 10 days, the larva cuts out a small oval case 

 and thereafter lives on the surface of the leaf, eating the epidermis 

 and green tissues in a circle about the case as far outward as it can 

 reach. Since the larva cannot reach the surface of the leaf directly 

 beneath its case this oval area remains green and when the larva bears 

 its case to a new location a disk-shaped green oasis, as it were, is left 

 surrounded by an oval band of whitened and bleached tissue. More- 

 over, as the larva molts it cuts out each time a larger and larger oval 

 piece of the leaf to add to its case. Thus it happens that in the latter 

 part of July and first part of August the foliage of infested trees becomes 

 brown with oval ring-like bands of bleached tissue and riddled with holes 

 of varying sizes. A badly infested woodland will present in August 

 and September a characteristic brownis.h appearance as though scorched 

 by fire. 



Felt (1912) records an area of woodland near Lake George of prob- 

 ably twenty-five acres as severely injured. Near Deposit, N. Y., a 

 sugar-bush of ten or twelve acres has been severely injured for four 

 or five years and during 1920 and 1921 it presented a striking and 

 severely injured aspect during the late summer. Many of the younger 

 trees in the central portions of this grove have been killed and the older 

 trees have been so injured that the grove has fallen off markedly in 

 its yield of sap during the last three seasons. In St. Lawrence 

 County the maple groves are suffering severely from the work of this 

 insect. Over much of the higher parts of the county the trees are 



