Thyridopteryx

Abstract: Insects in the families Aphididae, Cerambycidae, Chalcididae, Eurytomidae, Ichneumonidae, Ostomidae, Pyralidae, Pteromalidae, and Sarcophagidae were found in larval cases of the bagworm, Thyridopteryx ephemerae for mis, during winter on various plants growing in northeastern Kansas. From 1969 to 1971, 11.5% of the bagworms were parasitized (n = 3875 cases) ; 64.9% of the parasitized bagworms were attacked by ichneumonids ; 0.5% by chalcids; 0.5% by eurytomids; 0.2% by sarcophagids (n = 447 instances of primary parasitism by all insects). A pteromalid hyperparasite occurred in 44.5% of the bagworms attacked by pri mary parasites. Pyralids were associated only with bagworms on Juniperus virginiana; other insects were not restricted to bagworms on a particular host plant.

Abstract: Nutritional performance of early and late instar bagworm (Thyridopteryx ephemeraeformis Haworth) larvae was investigated as a function of host of origin and host type, using two taxonomically distant wild hosts, Salix nigra (Marshall) and Juniperus virginiana (L.). First instar growth and survival were higher on S. nigra; overall performance was similar on the two hosts in penultimate-final instars. There was no evidence for host associated differentiation with respect to nutritional performance. There were, however, significant genotype & environment interactions for several characters studied, suggesting that the potential for host associated differentiation exists.

Abstract: A group of 93 retail nursery customers were surveyed to determine their attitudes toward defoliation of American arborvitae, Thuja occidentalis L., caused by the bagworm, Thyridopteryx ephemeraefor...

Abstract: Larvae of the evergreen bagworm continue to feed after they are transferred from one host plant species to another. Periods as long as three generations on a single host plant apparently do not bring about any significant dependence on that host. Trees of host species that are uninfested or lightly infested in areas of high insect depreda- tion may be marginally resistant to the local insect population, but are probably not genetically resistant to the insect species as a whole. A recent paper in Science posed some in- teresting problems for scientists seeking to select or breed insect-resistant trees. In a well- conceived series of experiments, Edmunds and Alstad (1978) demonstrated the coevolution of populations of the black pineleaf scale, Nuculaspis californica, with individual host trees of Pinus ponderosa such that members of the differen- tiated insect populations were practically in- capable of colonizing neighboring trees of the same species. In such situations, the uninfested trees appeared to be "resistant" to the scale, even when crawlers were purposely transferred to them. Edmunds and Alstad (1978) stated that "in- sects that track individual tree defenses should show adaptations which confine a large proportion of their progeny to a host individual and reduce the flow of genes between insects on different trees." Many scale insects fit this description well. Other insect pests, including the so-called evergreen bagworm, Thyridopteryx ephemerae- formis, have similar habits.