Parasitoids of the autumn gum moth, Mnesampela privata (guenee) (Lepidoptera: Geometridae) in south-eastern Australia, with description of two new larval parasitoids

Abstract

Parasitoids were reared from cocoons present in larval shelters of Mnesampela privata (Guenée) collected at Altona and Shepparton, Victoria and Canberra (Lyneham Ridge), ACT. The most common primary parasitoid was a gregarious braconid wasp, described here as Cotesia geometricae Austin sp. nov. This species attacked host larvae at all locations and emerged from the fourth or fifth instar, pupating gregariously. A second braconid, described here as Glyptapanteles mnesampela Austin sp. nov., was found at Lyneham Ridge. This parasitoid was superficially similar to C. geometricae, attacked early-instar host larvae and also emerged from the fourth or fifth instar to pupate gregariously. One other solitary primary parasitoid. Casinaria micra Jerman & Gauld (Ichneumonidae), emerged from fourth or fifth instar larvae and pupated externally. At least five species of hyperparasitoids emerged from the cocoons of C. geometricae collected in Victoria: two species of Isdromas (Ichneumonidae), Mesochorus sp. (Ichneumonidae), Elasmus sp. (Elasmidae) and Megadicylas sp. (Pteromalidae), with one of the Isdromas species being most common. The larval-pupal parasitoid Heteropelma scaposum (Morley) (Ichneumonidae) emerged from 10% of pupae reared from larvae collected in the ACT over the same period as adults of M. privata. Sex and viability significantly influenced the weight of pupae of M. privata but pupae parasitised by H. scaposum could not be separated using weight. Notes and an illustrated key are provided to facilitate the easy identification of the parasitoids.