A framework for predicting competition between native and exotic hymenopteran parasitoids of lepidopteran larvae using taxonomic collections and species level traits

Abstract

Functional traits quantify the distinctiveness of ecological communities and provide a theoretical basis for understanding inter-specific competition, competitive exclusion, and limiting similarity. Functional traits can also be used to evaluate the risk of exotic species and biological control agents. The generalist parasitoid Meteorus pulchricornis (Wesmael 1835) (Braconidae: Hymenoptera) was used as a case study to evaluate the potential for inter-specific competition with resident hymenopteran larval parasitoid species in New Zealand. Information on taxonomic and life history traits were collated from published and unpublished literature, while morphological traits were obtained by measuring specimens in the New Zealand Arthropod Collection. Functional trait information was gathered for 89 parasitoid species, and a hierarchical agglomeration approach was used to cluster species based on similarity. A principal component analysis identified several key traits, including host development (idiobiosis, koinobiosis), site of development (ectoparasitoid, endoparasitoid), progeny per host, the host stage attacked, and ovipositor morphology. Analysis show that M. pulchricornis has the potential to compete with a different range of species, including biocontrol agents, and endemic or native species. Functional trait information using the literature and taxonomic collections can be used to complement current risk assessment tools.