Host handling and specificity of the hyperparasitoid wasp, Dendrocerus carpenteri (Curtis) (Hym., Megaspilidae): importance of host age and species

Abstract

The oviposition behaviour of Dendrocerus carpenteri (Curtis), an ectophagous hyperparasitoid of aphidiine wasps inside mummified aphids was examined. Hyperparasitoids were provided in the laboratory with pea aphids (Acyrthosiphon pisum) which had been parasitized by three different species of aphidiine wasps (Aphidius ervi, Ephedrus californicus and Praon pequodorum) ranging in physiological age from the late larval stage to the late pupal stage. Females accepted only the hosts inside mummified aphids; they ignored live aphids, and did not accept dead, but not yet mummified aphids, although the latter were sometimes probed with the ovipositor. Female behaviour in handling A. ervi or E. californicus mummies did not change with experience; handling and oviposition times were stereotypic. However, naive females needed experience to locate the cocoon of P. pequodorum and distinguish it from the empty aphid mummy. Host acceptance and specificity were influenced more by the developmental stage than the species of the primary parasitoid. In dichotomous choice tests, hyperparasitoids ‘preferred’ prepupae over younger pupae of A. ervi, but they did not distinguish between these stages of E. californicus; older pupae were accepted at a low rate. Host preference was not influenced by conditioning on the rearing host. We consider several constraints on the host range of D. carpenteri, and discuss alternative explanations of differential hyperparasitism in the field.

The developmental strategy of an idiobiont ectoparasitoid, Dendrocerus carpenteri : influence of variations in host quality on offspring growth and fitness

“…Insect eggs undergo physiological changes during embryogeny (Strand 1986) and represent a fast-diminishing resource for the parasitoid. The same may hold for insect pupae (King 1990), especially if the immature parasitoid is constrained in the kind or amount of host tissues it can digest (Urano and Hijii 1995;Chow and Mackauer 1999).…”

Masner, a new genus of Ceraphronidae (Hymenoptera, Ceraphronoidea) described using controlled vocabularies

“…Dendrocerus spp. (Megaspilidae: Megaspilinae), which span the breadth of trophic levels from primary to quaternary parasitoid, have been used as model systems for understanding the ecology of parasitoidism (Chow and Mackauer 1999;Mackauer and Völkl 2005;Zuparko and Dahlsten 1995). Few other hymenopteran taxa exhibit the range of host diversity seen in Ceraphronoidea.…”

Choreopraon totarae(Hymenoptera: Braconidae: Aphidiinae), a new parasitoid ofNeophyllaphis totarae(Hemiptera: Aphidoidea: Drepanosiphidae) in New Zealand

“…For example, in Praon pequodorum Viereck, a parasitoid of pea aphid (Acyrthosiphon pisum (Harris)), larvae may pupate inside the empty mummy, rather than beneath it, when reared at high temperatures between 27 8C and 32 8C (Chow & Sullivan 1984). The transition from internal to external pupation in Praini may have evolved as a defence against attack by pupal hyperparasitoids (Chow & Mackauer 1999). …”