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190 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
the excremental pellets of some larva. In most cases there were two 
distinct layers of the resin to be seen, the lower dry, hard, whitish, 
weather-beaten, having evidently been exposed during the winter, while 
the upper mass was fresh, softer, and of a hoary, bluish color on the 
surface, yellowish beneath, having the appearance of a comparatively 
recent exudation. These resinous lumps, when occurring upon twigs or 
limbs, were, in the great ma- 
jority of cases, upon the upper 
side, and were seldom found 
upon a larger limb than the 
one represented in the cut. 
A longitudinal section 
through one of these lumps 
showed a channel of greater 
or less size leading directly 
to the heart of the twig, and 
extending along toward its 
base for a distance of from 
25™™ to 50™™ (1 to 2 inches.) 
In this burrow was found a 
rather stout, yellowish-brown 
larva, apparently nearly full 
grown, and measuring about 
10™~ (.39 inch) in length. In 
other burrows theshort, stout, 
brown pupe were found. 
They were quite active, and 
retreated to the bottom of the 
mine when the resin was cut 
into. A ring of strong spines 
surrounded the posterior bor- 
der of each segment. and ena- 
bled them to move about in 
wh the mine with considerable 
Ae ere ene comienoc ana Y cynald. Tava. Spups, Adult rapidity. From other lumps 
the empty pupa skin was protruding for half its length, the pupa hay- 
ing worked itself to that position before giving forth the moth. 
Some of the burrows examined extended in both directions from the 
point of entrance. Occasionally, also, the twig at the point where the 
resin exuded was completely girdled, and in other cases eaten out to 
such an extent that a very slight force would suffice to break it off. The 
larvee were in some cases found with their heads at the mouth of the 
burrow, but in the majority of instances the opposite was the case. 
The moth which issues fron the burrows is quite small and soberly 
colored. In the figure it is represented natural size; the darker shades 
