title: Sexual complementarity between host humoral toxicity and soldier caste in a polyembryonic wasp.
abstract: Defense against enemies is a type of natural selection considered fundamentally equivalent between the sexes. In reality, however, whether males and females differ in defense strategy is unknown. Multiparasitism necessarily leads to the problem of defense for a parasite (parasitoid). The polyembryonic parasitic wasp Copidosoma floridanum is famous for its larval soldiers' ability to kill other parasites. This wasp also exhibits sexual differences not only with regard to the competitive ability of the soldier caste but also with regard to host immune enhancement. Female soldiers are more aggressive than male soldiers, and their numbers increase upon invasion of the host by other parasites. In this report, in vivo and in vitro competition assays were used to test whether females have a toxic humoral factor; if so, then its strength was compared with that of males. We found that females have a toxic factor that is much weaker than that of males. Our results imply sexual complementarity between host humoral toxicity and larval soldiers. We discuss how this sexual complementarity guarantees adaptive advantages for both males and females despite the one-sided killing of male reproductives by larval female soldiers in a mixed-sex brood.
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Uka
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Graduate School of Science and Technology and Department of Mathematical and Systems Engineering, Shizuoka University, Hamamatsu, 432-8561, Japan.|Marine Biosystems Research Center, Chiba University, Kamogawa, Chiba 299-5502, Japan.|Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Yoshimura
authors.affiliation: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Kikuo
authors.initials: K
authors.lastname: Iwabuchi
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D005260:Female; D007814:Larva / Q000469:parasitology / Q000502:physiology; D007915:Lepidoptera / Q000469:parasitology* / Q000502:physiology*; D008297:Male; D012098:Reproduction / Q000502:physiology; D012641:Selection, Genetic / Q000502:physiology; D012725:Sexual Behavior / Q000502:physiology*; D014863:Wasps / Q000469:parasitology* / Q000502:physiology*