586 FIFTH REPORT OP THE ENTOMOLOGICAL COMMISSION. 
ribs. Bometimea two rows of these blisters arc found on the same leaf. The place 
of insertion <»f the ovipositor is always plainly visible, as a nearly straight slit 
(usually closed) of ferruginous or brownish color at or near that edge of the blister 
which is Dearest to the margin Of the leaf, thus indicating that while ovipositing 
the female lly grasps the Sdge of the leaf with her fore legs. (Fig. 194, a.) 
Leaves infested with eggs, although not rare, were by no means BO abundant as 
should have been expected from the extent of the iujury indicted by the imago-. A 
great many plants (and among them many with their tops cut off) were DOtinfi 
while occasionally a plant could lie found with four or five infested leaves, mostly 
about the middle or near the top of the plant. 
The egg, when about ready to hatch, is oblong oval, somewhat flattened, and with 
its shell so thin and pliable that it not only loses its regular shape by the slightest 
pressure, but even by the position or movements of the embryo larva within. The 
shell is perfectly hyaline, with no visible sculpture besides some fine, irregular, and 
variable wrinkles. Its surface is very sticky. At an earlier stage the egg is elon- 
gate and nearly cylindrical. Through the whitish epidermis of the blister the shape 
of the egg is always readily perceptible as a transverse (i. e., parallel or nearly 
parallel to the margin of the leaf) object of a decided green color. (Fig. 194, c.) 
The young larva, after hatching remains for some time within the blister, but 
finally leaves it through an irregular slit at the middle of the epidermis. Its color 
is bluish gray. (Fig. 194, d.) 
The recently excluded larvae are uniformly curled up on the under side of the leaf. 
Three varieties of cultivated willows were found to be injured by the perfect saw- 
fiy, while egg blisters could only be found on two varieties. 
The willows affected were the American green ozier, the Welsh, and the Golden. 
Remedies. — It would be quite practicable, considering the small area to be pro- 
tected and the conspicuous size of the insect and its clumsy movements, to catch the 
perfect flies by means of a net ; but the application of arsenical poisons would be 
surer, and would also rid the willows of many other enemies. 
" For some years" says Mr. Bruner " the large saw-fly (Cimbex americana) has at- 
tracted my attention at various points in Nebraska, by its habit of frequenting 
hedges of white willow in preference to the various species of the native willow. 
During the summer its large, green, slug-like larva? would be met with from time to 
time, but not until the present summer have I learned that it appeared in such great 
numbers as to completely defoliate the trees. 
"About three weeks ago (August 31) I visited Mr. G. M. Dodge, of Glencoe, Dodge 
County, and while driving across the country observed that nearly every hedge of 
this willow had been more or less injured by some insect which had stripped the 
trees of most of their leaves. I at once attributed the work to the striped cotton- 
wood beetle (Plagiodera scripta), which, as you have shown, has been known to injure 
various species of willow, as well as the poplars and cottonwood in this and other 
sections of the country. Upon speaking to Mr. Dodge in reference to the subject, he 
informed me that the work was that of the above named saw-fly. He also stated 
that the larva? had been so numerous on many of the hedges in his immediate neigh- 
borhood as to completely defoliate the trees before they (the larva?) had attained full 
growth, and that they had therefore proved the cause of their own destruction. 
'•At other points, however, where the larva? were less numerous, they have matured, 
and will evidently make their appearance in force next season, provided no unfore- 
seen providence intervenes. 
'• Mr. Dodge also informed me that this saw-fly has been steadily on the increase for 
the past three or four years— always working on the white willow in preference to 
the native species." 
A Ciinbex-like saw-fly larva occurred on the willow at Brunswick, Me., 
August 6, 1886, September 3, 1885. It is represented by the very poor 
sketch in PL v, fig. 11. 
