A new species of Podapolipus (Acari: Heterostigmata: Podapolipidae) from an Australian gryllacridid cricket (Orthoptera), with keys to orthopteran-associated species of the genus

A new species of the ectoparasitic mite genus Podapolipus Rovelli & Grassi, 1888 from a recently described species of the raspy cricket genus Chauliogryllacris Rentz, in Rentz and John,1990 (Orthoptera: Gryllacrididae) is described. The main distinctions of Podapolipus gryllacridi n. sp. from its described congeners from orthopterans are the larval female and adult male having all dorsal and ventral idiosomatic setae, except the greatly elongated pair of scapular setae (and the caudal setae of the larval female), reduced to the size of microsetae; the larval female having separate tergites C and D; the male having an entire prodorsal shield, with apex of the aedeagus between bases of setae v1; and the adult female having smooth dorsal shields. Novel biological features of this parasite include its adult females’ dwelling in the hollow sternal apodemes of their host, and its larval females using their host’s other parasite, a gamasine mite, as phoretic and facultative hyperparasitic hosts. Keys are presented for the larval females and adult males of Podapolipus species associated with orthopterans. Problems with the generic concept of Podapolipus and closely related genera are reviewed. This is the first record of a podapolipid associated with orthopterans of the family Gryllacrididae.

Interaction of Apanteles fumiferanae (Hymenoptera: Braconidae) and Nosema fumiferanae (Microsporidia) parasitizing spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)

The relationship between a braconid parasitoid, Apanteles fumiferanae, and a microsporidian pathogen, Nosema fumiferanae, two larval parasites frequently coincident in the spruce budworm, Choristoneura fumiferana, was examined in the laboratory. When Apanteles was reared in spruce budworm infected with high levels of Nosema (i.e., more than 20 × 106 spores/mg dry weight), there was a slight reduction in the within-host rate of development of larval female Apanteles, but survival, within-cocoon rate of development, cocoon weight, and adult longevity were not affected. There was no evidence that any stage of Apanteles was infected with spores of Nosema. A few adult female parasitoids were found to carry spores of Nosema on their integuments but it is unlikely that Apanteles is an important vector of the microsporidian. We conclude that these natural enemies of budworm do not interact significantly in their common host. The implications for population dynamics of the spruce budworm and mass rearing of Apanteles are discussed.