INSECTS INJURING SPRUCE. 
855 
Fig. 287.— Single 
pierced cone (orig- 
inal). 
The Spruce Cone-worm is usually confined to the young cones, into 
which it bores and mines in different directions, eating 
galleries passing partly around the interior, separating 
the scales from the axis of the cones (Fig. 287). After 
mining one cone the caterpillar passes into an adjoin- 
ing one, spinning a rude silken passage connecting the 
two cones. Sometimes a bunch of three or four cones 
is tied together with silken strands ; while the castings 
or excrement thrown out of the holes form a large, con- 
spicuous light mass, sometimes half as large as one's 
fist, out of which the tips of the cones are seen to pro- 
ject (Fig. 288). Besides these unsightly masses of cast- 
ings, the presence of the caterpillars causes an exuda- 
tion of pitch, which clings in large 
drops or tears to the outside of the 
adjacent more or less healthy cones. 
Where much affected the young 
cones turn brown and sere. 
The same worms had also attacked 
the terminal branches and twigs of 
the same tree, eating off the leaves 
and leaving a mass of excrement on 
one side of the twig, within which 
they had spun a silken gallery in 
which the worm lived. 
On removing the bunches of dis- 
eased cones to Providence, one cater- 
pillar transformed in a warm cham- 
ber into a moth, which appeared the 
end of October; its metamorphosis 
was probably accelerated by the un- 
usually warm autumnal weather. 
All the others had by the 1st of 
November spun within the mass of 
castings a loose, thin, but firm, oval 
cocoon, about half an inch long and 
a quarter of an inch wide, but the 
larvae had not yet begun to change 
to chrysalids. Whether in a state of nature they winter over in the 
larval state within their cocoons, or, as is more likely, change to pupae 
in the autumn, appearing as moths by the end of spring, remains to be 
seen. 
The chrysalis is of the usual Phycid appearance, rather slender, but 
with the abdominal tip blunt, with no well-marked cremaster or spine, 
though ending in the usual six curved stiff bristles, by means of which 
it hooks on to the walls of its cocoon, thus maintaining itself in its nat- 
ural position. 
Fig. 288.— Mass of infested cones (original). 
