Temperature and developmental interactions in a multitrophic parasitoid guild

The lower developmental thresholds and thermal constants (day-degree requirements) for three larval parasitoids and one hyperparasitoid were estimated and compared with those of their host, the eucalypt defoliating leaf beetle, Paropsisterna (=Chrysophtharta) agricola Chapuis (Coleoptera: Chrysomelidae: Paropsini). The lower developmental thresholds and thermal constants for the primary parasitoids Eadya paropsidis Huddleston and Short (Hymenoptera: Braconidae: Euphorinae), Paropsivora australis Macquart and Balde striatum Rice (Diptera: Tachinidae: Blondeliini) were estimated at 5.9°C, 294 DD (egg to pupa), 6.2°C, 385 DD (egg to adult), and 6.3°C, 345 DD (larva to adult) respectively. Developmental thresholds of all three parasitoids were lower than their host, and all three required fewer day-degrees for generational development than their host. The developmental threshold for Mesochorus sp. (Hymenoptera: Ichneumonidae: Mesochorinae), a hyperparasitoid of the tachinid fly, B. striatum, was 9.7°C which is higher than B. striatum, the primary host and P. agricola, the secondary host. The thermal constant of 333 DD for Mesochorus sp. is also lower than its primary and secondary host. © 2009 Australian Entomological Society.