Body size, host choice and sex allocation in a spider-hunting pompilid wasp
Two important relationships in parasitoid evolutionary ecology are those between adult size and fitness and between host quality and sex ratio. Sexually differential size–fitness relationships underlie predicted sex-ratio relationships. Despite each relationship receiving considerable attention, they have seldom been studied simultaneously or using field data. Here we report the biology of Anoplius viaticus paganus Dahlbom, a little known parasitoid of spiders, using field and laboratory data. We found that larger foraging females were able to select larger host spiders from the field, thus identifying a relatively novel component of the size–fitness relationship. Larger offspring developed from larger hosts and, in agreement with the prediction of the host quality model of sex allocation, were generally female. Data on the size–fitness relationship for males are lacking and, in common with many prior studies, we could not evaluate sexually differential size–fitness relationships as an explanation for the observed sex-ratio patterns. Nonetheless, A. v. paganus exhibited one of the strongest relationships between host size and offspring sex ratio yet reported. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87, 285–296.
Document Type: Research Article
Department of Biological Sciences, East Tennessee State University, Box 70703, Johnson City, TN 37614– 1710, USA
Department of Evolutionary Biology, Kossuth University, H-4010 Debrecen, Hungary
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK
Publication date: February 1, 2006