title: Role of supplemental foods and habitat structural complexity in persistence and coexistence of generalist predatory mites.
abstract: Plant traits can influence the interactions between herbivore arthropods and their natural enemies. In these interactions generalist predators are often present, preying on herbivores and also on other arthropods in the same trophic guild. Variation in the strength of intraguild predation (IGP) may be related to habitat structural complexity and to additional resources outside the narrow predator-prey relationship. In this paper we study the food web interactions on grape, which involves two generalist predatory mites. We evaluated the effects of grape powdery mildew (GPM) as supplemental food, and habitat structural complexity provided by domatia. The inoculation of GPM resulted in higher predatory mite densities and reduced the negative impact of unfavorable leaf structure for one species. Access to domatia was the main factor in promoting population abundance and persistence of predatory mites. Access to domatia and GPM availability favored the coexistence of predatory mites at a low density of the intraguild prey. Our findings suggest that structural and nutritional diversity/complexity promote predatory mite abundance and can help to maintain the beneficial mites - plants association. The effect of these factors on coexistence between predators is influenced by the supplemental food quality and relative differences in body size of interacting species.
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Italy.|Department of Entomology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pozzebon
authors.affiliation: Department of Entomology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Loeb
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Duso
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000502:physiology; D017753:Ecosystem; D005260:Female; D020387:Food Chain; D006790:Host-Parasite Interactions; D054884:Host-Pathogen Interactions; D008925:Mites / Q000502:physiology*; D008954:Models, Biological; D010935:Plant Diseases / Q000382:microbiology / Q000469:parasitology; D018515:Plant Leaves / Q000382:microbiology / Q000469:parasitology; D011157:Population Dynamics; D011235:Predatory Behavior / Q000502:physiology*; D027843:Vitis / Q000382:microbiology / Q000469:parasitology*