title: An endoparasitoid avoids hyperparasitism by manipulating immobile host herbivore to modify host plant morphology.
abstract: Many parasitic organisms have an ability to manipulate their hosts to increase their own fitness. In parasitoids, behavioral changes of mobile hosts to avoid or protect against predation and hyperparasitism have been intensively studied, but host manipulation by parasitoids associated with endophytic or immobile hosts has seldom been investigated. We examined the interactions between a gall inducer Masakimyia pustulae (Diptera: Cecidomyiidae) and its parasitoids. This gall midge induces dimorphic leaf galls, thick and thin types, on Euonymus japonicus (Celastraceae). Platygaster sp. was the most common primary parasitoid of M. pustulae. In galls attacked by Platygaster sp., whole gall thickness as well as thicknesses of upper and lower gall wall was significantly larger than unparasitized galls, regardless of the gall types, in many localities. In addition, localities and tree individuals significantly affected the thickness of gall. Galls attacked by Platygaster sp. were seldom hyperparasitized in the two gall types. These results strongly suggest that Platygaster sp. manipulates the host plant's development to avoid hyperparasitism by thickening galls.
authors.affiliation: Biosystematics Laboratory, Graduate School of Social and Cultural Studies, Kyushu University, Fukuoka, Japan; Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan; Entomological Laboratory, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Matsuo
authors.affiliation: Biosystematics Laboratory, Graduate School of Social and Cultural Studies, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Entomological Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Yukawa
authors.affiliation: Laboratory of System Ecology, Faculty of Agriculture, Saga University, Saga, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Tokuda
mesh_terms: D000818:Animals; D004175:Diptera / Q000472:pathogenicity*; D029756:Euonymus / Q000378:metabolism*; D060434:Herbivory; D054884:Host-Pathogen Interactions / Q000502:physiology*; D010935:Plant Diseases; D018515:Plant Leaves / Q000378:metabolism*; D010941:Plant Tumors / Q000209:etiology*; D011235:Predatory Behavior; D012098:Reproduction / Q000502:physiology