REPORT OF THE STATE ENTOMOLOGIST I912 87 
fair that more of such trees will die or parts of large limbs break 
off in a year or two. Our attention was also called to several large 
sugar maples now dead, which were marked as having been 
sprayed the preceding year and had not been removed last year 
because it was supposed that they had not been seriously affected 
by the application. An examination of a number of representative 
trees here and there only served to confirm our findings of the 
preceding season and to exonerate injurious insects from direct 
responsibility in the wholesale destruction of sugar maples. The 
local character of the injury and the difficulty of attributing the 
trouble to malnutrition, overcrowding or other general adverse 
conditions is strongly illustrated by small to moderate sized hard 
maples standing in front of numbers 125, 151 and 157 Cottage 
avenue. The lower limbs of each of these trees had evidently died 
the preceding year and had been removed, although the maples 
stood in thrifty lawns some distance from the street and where 
conditions were most favorable for a vigorous growth. 
After we had made examinations of the Mount Vernon maples 
and reached certain conclusions, we learned of similar injury fol- 
lowing the application of a miscible oil a few years earlier to sugar 
maples in the vicinity of Philadelphia. There were about 100 trees 
sprayed, sugar maples and Norway maples alternately, and at 
least 75 per cent of the former, we are informed, died soon after 
the treatment. Those conversant with the conditions in this latter 
case attribute the injury to the application of oil. 
The sensitiveness of the sugar maple to oil and the possibility 
of the rapid death following treatment therewith, is evidenced by 
a photograph taken by the late Professor Slingerland in July 1903 
and kindly placed at our disposal by his successor, Prof. G. W. 
Herrick. The photograph shows several dead sugar maples and 
the original record is as follows: ‘‘ Effect of kerosene bands on 
maple trees. Maple trees treated with a band of kerosene in 1902 
in tront of fraternity house on Seneca street (W. H. Sage home). 
Taken in July 1903. Trees practically dead.” A band saturated 
with kerosene is quite different from a trunk sprayed with petrol- 
eum or miscible oil. Nevertheless it is possible to conceive of 
conditions under which enough oil, either pure or as an emulsion, 
might be left upon the trunk after the evaporation of water or 
other emulsifying fluids and bring about a condition nearly identi- 
‘al with that produced by oil-saturated bands. 
The unfortunate developments on sugar maples, following the 
