188 
HALF IIOUKS WITH INSECTS. [Packard. 
cultivation of ichneumon flies as the “right arm of the ser¬ 
vice” in an enlightened agriculture. 
The Apple Micropteryx .— The most abundant leaf miner 
of the apple, so busy a laborer that for several years past 
nearly every other leaf on the apple trees in my garden wit¬ 
nesses their plodding, patient work, is the Micropteryx po- 
mivorella —nearly all these minute slender-winged moths 
have monstrously long names. 
The caterpillar is a minute, dark, pea-green, flat worm, 
the body thickest in the middle and very soft. It is about a 
line in length. It eats its way in the interior of the leaf, 
between the upper and the under side, feeding on the soft 
pulp. Its burrow is marked by a broad waved dark line on 
the leaf, which widens at the farther end, and is somewhat 
puffed out, owing to the presence of the fully fed caterpillar. 
In this little terminal chamber the worm rests, and when 
anxious to leave it in order to spin its cocoon effects its 
escape through a slit, which it has had the instinct or com¬ 
mon sense previously to cut with its jaws. So abundant is 
it, that multitudes of these little green worms may be seen 
hanging helplessly from the leaves of the tree. Suspended 
by this thread they swing to and fro, until they strike some 
twig, whence they go to the bark of the trunk and larger 
branches. Here in warm days late in September and. 
early in October, the worms spin a peculiar flattened, round, 
silken, yellow cocoon, about a line in diameter. In con¬ 
finement I have noticed that it will spin its cocoon on the 
leaves, but in nature it is careful to deposit them on the 
branches, where it remains through the winter. The larva 
completes the cocoon, at least all that is visible, within the 
space of one hour. The moth was found in considerable 
abundance resting on the under side of apple-leaves the 19th 
of June. 
The body and wings are of an uniform dark bronze hue, 
with purple and metallic reflections; the fringe is concolo- 
28 
