THE BORERS OF CERTAIN SHADE TREES. 593 
etrate the solid wood an equal distance. It is supposed that 
three years are required to mature the insect. Various ex- 
pedients have been tried to arrest their course, but with- 
out effect. A stream, 
thrown into the tops of 
trees from the hydrant, 
is often used with good 
success to dislodge other 
insects; but the borer- 
beetles, when thus dis- 
turbed, take wing and 
hover over the trees till 
all is quiet, and then 
alight and go to work 
again. The trunks and 
branches of some of the trees have been washed over with 
Fig. 122. various preparations without benefit. 
Boring the trunk near the ground, and 
putting in sulphur and other drugs, and 
plugging, have been tried with as little 
effect. 
The city of Philadelphia has suffered 
grievously from this borer. 
Dr. Swift remarks, in 1844, that " the 
trees in Washington and Independence 
Squares were first observed to have 
been attacked about seven years ago. 
Within two years it has been found nec- 
essary to cut down forty-seven European 
lindens in the former square alone, where 
! there now remain only a few American 
foret tetnator, arra TOGENE, and these a good deal eaten.” 
(Ost In New England this beetle should be 
looked for during the first half of June. 
The Poplar tree is infested by another species of Saperda 
(S. calcarata of Say). This is a much larger beetle than 
AMER. NATURALIST, VOL. IV. 75 
Fig. 121. 
6 
Saperda inornata and larva. 
