Euplectrus melanocephalus Girault (Hymenoptera: Eulophidae), an ectoparasitoid of larvae of fruit-piercing moths (Lepidoptera: Noctuidae: Catocalinae) from northern Queensland

ABSTRACT

Euplectrus melanocephalus is a gregarious, primary ectoparasitoid of larvae of the fruit-piercing moth genus Eudocima Billberg (Noctuidae: Catocalinae). In northern Queensland, E. melanocephalus parasitised second- and third-instar larvae of Eud. aurantia (Moore), Eud. cocalus (Cramer), Eud. fullonia (Clerck), Eud. iridescens (Lucas), Eud. jordani (Holland) and Eud. materna (L.). In the laboratory, E. melanocephalus also parasitised Eud. salaminia (Cramer) but failed to oviposit on larvae of two other noctuids, Erebus terminitincta (Gaede) (Catocalinae) and Spodoptera litura (F.) (Amphipyrinae). When parasitising Eud. materna, eggs of E. melanocephalus were deposited dorsolaterally on one of the first five abdominal segments of second- and third-instar larvae. Fourth instars were occasionally parasitised when the density of parasitoids was increased, but successful development to adults was markedly reduced. Pupation took place between the leaf substrate and host. Female parasitoids provided with honey survived 21 days (range = 1–42) and deposited 112 eggs (range = 11–196), while development from egg to adult occupied 12–13 days at 25°C. The minimum temperature threshold for oviposition was 17.5°C, while minimum and maximum development thresholds for larvae were 18.5°C and 30°C, respectively. Studies on the parasitoid/host interactions of E. melanocephalus indicate that it is adapted principally to the larvae of Eudocima spp.