Picky predators and the function of the faecal shield of a cassidine larva

摘要: Summary 1The faecal shield of cassidine larvae is generally thought to have evolved as a defence against predators, but field evidence for this only anecdotal. We investigated the effectiveness natural enemies and protection from ultraviolet (UV-B) radiation in beetle Cassida rubiginosa Muller (Coleoptera, Chrysomelidae). also if construction bearing associated with fitness costs absence enemies. 2Using continuous video surveillance individual prey, we determined predator complex field. Against main predator, paper wasp Polistes dominulus Christ (Hymenoptera, Vespidae), was not effective at all. Only few other generalist predators attacked thus represented no major mortality factor. By contrast, highly parasitoids, an unexpected trait described here first time. 3In dual-choice bioassays found attractive effect on endoparasitoid Foersterella reptans Tetracampidae), removed facilitated oviposition. 4There protective UV-B laboratory experiment. However, irradiated suffered higher rate reached lower pupal weight, independent whether or they carried shield. 5We measurable shield. Advantages (protection desiccation, wind) seem outweigh costs, even enemies. 6Although many studies defensive function Cassidine shields been published, our knowledge consider actual predation pressure situations. This step rarely undertaken proposed traits. verification that selection fact present crucial demonstrating value any trait.