. The bagworm. (Thyridopteryx ephemeraeformis Haw.). f the females, andwhen one is found in which the head of the female is near the end,showing that she has emerged from her chrysalis skin, the male pusheshis enormously protrusive and, in fact, telescopic genital apparatus upinto the bag to the anal end of the female and fertilizes her. Thefemale then works her way back into the chrysalis skin, gradually fillingit with eggs until more than half of it is filled, scattering in among theeggs some of the sparse hairs from her body. Having done this she forces her shriveledbody out of the open-ing
. The bagworm. (Thyridopteryx ephemeraeformis Haw.). f the females, andwhen one is found in which the head of the female is near the end,showing that she has emerged from her chrysalis skin, the male pusheshis enormously protrusive and, in fact, telescopic genital apparatus upinto the bag to the anal end of the female and fertilizes her. Thefemale then works her way back into the chrysalis skin, gradually fillingit with eggs until more than half of it is filled, scattering in among theeggs some of the sparse hairs from her body. Having done this she forces her shriveledbody out of the open-ing, falls to the ground,and dies. The eggs re-main in this way untilthe following spring,when they hatch, aspreviously described. There is thus only onegeneration annually. JSote.—There is a possi-bility that the bags of thisextremely common insectmight be made commer-cially useful. Its silk, froma practical standpoint, hasalways been ignored, but itis firmer and stronger andmore easily spun as cardedsilk than that of most othernative silk Fig. 5.—Bagworm at (a, b, c) successive stages of growth, c, Malebag; d, female bag. Natural size (from Howard). NATURAL ENEMIES. Although apparently well protected from the attacks of birds byits tough case, the bagworm is somewhat extensive!} parasitized byseveral forms of ichneumon and chalcis flies, most of them specieswhich affect also similar tree-feeding caterpillars. Prominent amongthese is the common Pimpla inquisitor Say (fig. 6), which, however,more commonly parasitizes the tussock moth and tent related P. conquisitor Say is also a parasite of the bagworm anda third species of ichneumon, Allocota (Hemiteles) thyridopterigis Riley(fig. 7), is usually the most abundant of all. Four or five individualsof this species commonly infest a single bagworm, spinning for them-selves white silken cocoons within the bag. [Cir. 971 a Malacosoma spp. The species last mentioned was for many years credited with beinga
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