Fifth report of the United States Entomological Commission, being a revised and enlarged edition of Bulletin no7, on insects injurious to forest and shade trees . B-WORM. 255 secondary parasites. The white silky cocoon is formed almost under the middle of ahalf grown caterpillar, and is fastened securely to the object its host happened to restupon, and but slightly to the host itself, which is readily carried to the ground bywind and rain, and can therefore only be found in position in the more shelteredplaces, such as cracks and fissures of the bark of trees. But one Jpanteles is foundin a ca
Fifth report of the United States Entomological Commission, being a revised and enlarged edition of Bulletin no7, on insects injurious to forest and shade trees . B-WORM. 255 secondary parasites. The white silky cocoon is formed almost under the middle of ahalf grown caterpillar, and is fastened securely to the object its host happened to restupon, and but slightly to the host itself, which is readily carried to the ground bywind and rain, and can therefore only be found in position in the more shelteredplaces, such as cracks and fissures of the bark of trees. But one Jpanteles is foundin a caterpillar, so that each white cocoon indicates, like a tombstone, the death of avictim. In some places, and notably upon the trunks of poplars, these cocoons wereso numerous as to attract attention ; it seemed as if the trunk had been sprinkledwith whitewash. But notwithstanding such vast numbers, but two specimens ofthe architects of these neat cocoons were raised; all the rest had been parasitizedby secondary parasites. It is barely possible, however, that some specimens mayhibernate in their cocoons, since numbers of them have as yet (December 20, 1886). Fig. 94.—An Apanteles : a, female fly ; 6, outline of head of larva in posi-tion to show the chitinized parts of the mouth, the mandibles not visible,being withdrawn; c, one of its mandibles are seen within the bead of amounted specimen; d, cocoon; e, joint of antenna—all enlarged: naturalsize of o and d in hair-line. After Riley. not revealed any insects. The winged Apanteles leaves the cocoon by a perfectlyround orifice in the front by cutting off a little lid, which falls to the ground. Itsparasites, however, leave by small holes cut through the sides. These secondaryparasites were very common late in September and early in October, and busily en-gaged in inserting their ovipositors through the tough cocoon into their victimwithin. It seems as if the cocoons formed early in the season were on an average alittle smalle
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