Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomol00smit Year: 1906 THE INSECT WORLD. 275 It is, indeed, a helpless, grub-like creature that awaits the visit of the male without making an attempt to emerge from its sac, in wliich it remains even after impregnation. The eggs develop, finally fill up the bag, and then the female dies, the eggs rest- ^^'^â ing in the fluffy mass already described until the spring fol- lowing. This species is best treated by picking off and destroying the bags during the wint
Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomol00smit Year: 1906 THE INSECT WORLD. 275 It is, indeed, a helpless, grub-like creature that awaits the visit of the male without making an attempt to emerge from its sac, in wliich it remains even after impregnation. The eggs develop, finally fill up the bag, and then the female dies, the eggs rest- ^^'^â ing in the fluffy mass already described until the spring fol- lowing. This species is best treated by picking off and destroying the bags during the winter, and if this is thoroughly done no caterpillars will appear on the trees in the spring, unless they crawl on from other points where an egg-sac may happen to be attached. The meas- ures recommended against the 'white-marked tussock moth' can be employed here as well, and trees once cleared can be kept free without much diffi- culty. When arbor-vitae is at- tacked, the picking should be thoroughly and carefully done, because these hedges suffer very rapidly, and once defoliated, usually die. In orchards where spraying is done against the codling-moth, the 'bag-worms' are destroyed incidentally and no special measures need be taken against them. Next follows the family of ' prominents,' so called from the fact that the moths frequently have a tooth at the inner margin of the fore wings, and the caterpillars are sometimes a little humped. They are technically termed NotodontidcE. Most of then} have a small, retracted head, many of them a short or obsolete tongue, and some are more or less troublesome on cul- tivated plants. One of the best known is the 'yellow-necked caterpillar' often found feeding on apple-trees in colonies of from fifty to more than one hundred. When full grown it is nearly two inches The bag-worm.âa, sack of female cut open to show the grub-like creature at its mouth ; b, the female removed from the bag, much enlarged.
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