750 FIFTH REPORT OP THE ENTOMOLOGICAL COMMISSION. 
iiniy !ir vrn Inclosing the base of the bad and the surrounding new leaflets; but 
moel of them, Like B, fru$trama, live entirely within the shoot from the moment they 
have bored their iray i n t «» it. and undergo therein their transformations. 
The injury done by B.firuttranu to the pitch pin.- | Pinui rUjida) of Nantnoki 
soon detected in the months between May and September by noticing the dead nee- 
dles at the rery tip of a shoot otherwise of s fresh green color, or only partially with- 
ered near the dead needles. The egg must be laid, as Rat/.eburg presumes it to be 
in the Enropean Bpecies, between the scales of the bursting bud, from whence the 
caterpillar eats it-- waj at birth into the very heart of the bad near the extreme tip : 
lor to this pait are tin- youngest caterpillars confined. From this point the growing 
caterpillar burrows down the stem, often for from 4 to 6 centimeters, and thus eats 
the very life out of the tree : for with one of these insects at nearly every bud. si 
the case in the tree I iiit down, and in the accessible branches of many others exam- 
ined at different times, the tree most speedily perish. As the caterpillar works 
downward, one by on • the needles find their supply of nourishment cut off. case their 
further growth, lose their color, and wither— the change in coloration of the needles 
showing the progress of the pest. Fig. ti shows the appearance of one of these twigs 
in which the caterpillar has bored a couple of centimeters. Some of the terminal 
needles, as may be seen by comparison with fig. .">. which represents an unharmed 
twig of the same tree, have scarcely had a chance to grow at all before being robbed 
of their means of support, and have turned quite yellow; further down the stem, 
where also they are wholly withered, they are a little louger; still further they are 
longer yet, and only partially withered, showing more recent attack ; and it is not 
until the wholly green and fresh needles are reached that they are of the normal 
length. The difference between an uninjured twig and one that has been attacked 
is really greater than appears by comparison of figs. 5 and G; for, as will be seen on 
comparing the lower normal needles of each, fig. 5 represents a shoot with much 
shorter needles than fig. 6 would normally have had throughout. The dome-shaped 
contour of the needle tips in the healthy shoots is well represented in fig. 5, and the 
contrast to this which fig. 6 exhibits is very marked, and tells the story of the dam- 
age done. The specimen represented in fig. 6 was chosen rather to exhibit this point 
being perhaps more marked than usual. Generally the whole shoot is uunaturally 
swollen and disfigured by the pitch that has exuded from the injuries caused by 
the caterpillars, as may be seen ou removing the needles: this appears in tig. 9 of the 
plate, to compare with which a healthy shoot with the needles removed is shown in 
fig. 7. 
As the insect is probably double-brooded, the second generation has to attack 
shoots already grown or nearly grown, in which case, of course, the change of con- 
tour of the tip, seen ou comparing lig. G with fig. 5, does not ensue; but the withered 
needles are all of nearly the full length, as shown in fig. 8. In this figure the stem 
has been cut longitudinally, to show the nature and extent of the borings of the 
caterpillar. The middle of the stem is found pierced by a slender cylindrical passage 
as far as the dead needles continue; the passage is lined with silk and foul with ex- 
crement, which has been removed from the specimen drawn. As far as the boring 
has been carried the withered needles fall from their position on being touched, hav- 
ing nothing but a shell for their support. 
When the caterpillar is fully grown it selects a place within its burrow wherein to 
change to chrysalis; this is usually at the bottom of the burrow, but iu a thick 
doubt of their very close relationship, but the difference in the habits of the larva 1 
in the two localities, both during active life and when about to undergo metamor- 
phosis, would be very singular if they belong to the same species. The specimens 
carefully studied by him, also, were found ou a different species of pine. I have 
made no comparison, but only desire here to call the attention of those who may 
hereafter study this iusect to this fact. For further account of Mr. Comstock's 
observations see the close of this paper. 
