266. Humble Bee Parasite.
We figure the Hop-vine moth and the larva (Fig. 265) which abound on hops the last of summer. Also, the Ilythia colonella (Fig. 266, a, pupa), known in England to be a parasite of the Humble bee. We have frequently met with it here, though not in Humble bees' nests. The larvæ feed directly upon the young bees, according to Curtis (Farm Insects). The Spindle-worm moth (Gortyna zeæ), whose caterpillar lives in the stalks of Indian corn, and also in dahlias, flies this month. The withering of the leaves when the corn is young, shows the presence of this pest. The beetles of various cylindrical Bark borers and Blight beetles (Tomicus and Scolytus) appear again this month. During this month the Tree cricket (Œcanthus niveus, Fig. 267) lays its eggs in the branches of peach trees. It will also eat tobacco leaves.
267. Tree Cricket.
268. Ennomos subsignaria.
We figure (268) the moth of Ennomos subsignaria, the larva of which is so injurious to shade trees in New York City. It is a widely diffused species, occurring probably throughout the Northern States. We have taken the moth in Northern Maine. We have received from Mr. W. V. Andrews the supposed larvæ of this moth. They are "loopers," that is, they walk with a looping gait, as if measuring off the ground they walk over, whence the name "Geometers," more usually applied to them. They are rather stout, brown, and roughened like a twig of the tree they inhabit, with an unusually large rust-red head, and red prop-legs, while the tip of the body is also red. They are a little over an inch long.
The Insects of September.
Few new insects make their first appearance for the season during this month. Most of the species which abound in the early part of the month are the August forms, which live until they are killed by the frosts late in the month. From this cause there is towards the end of the month a very sensible diminution of the number of insects.
The early frosts warn these delicate creatures of approaching cold. Hence the whole insect population is busied late in the month in looking out snug winter quarters, or providing for the continuance of the species. Warned by the cool and frosty nights, multitudes of caterpillars prepare to spin their dense silken cocoons, which guard them against frost and cold. Such are the "Spinners," as the Germans call them, the Silk moths, of which the American Silk worm is a fair example. The last of September it spins its dense cocoon, in which it hibernates in the chrysalis state.