188 HALF HOUES "WITH INSECTS. [Packard. 



cultivation of ichneumon flies as tlie "rigiit arm of tlie ser- 

 vice" in an enlightened agriculture. 



The Apple MIcropiteryx. — The most abundant leaf miner 

 of the apple, so bus}^ a laborer that for several j-ears 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 

 puflTed 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 lai'ger 

 branches. Here in warm days late in September and 

 early in October, the worms spin a peculiar flattened, round, 

 silken, j-ellow 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 bodj^ and wings are of an uniform dark bronze hue, 

 with purple and metallic reflections ; the fringe is concolo- 



28 



