Survey and Seasonal Fluctuation of Phytoseiid Mites (Acari: Phytoseiidae) Associated with Grapevine in Arid Climates

Abstract

Field surveys were conducted in major grapevine-growing areas located under arid climatic conditions to investigate the diversity and seasonal fluctuation of phytoseiid mites associated with vineyard ecosystems. Sampling was performed at regular intervals throughout the growing season by collecting leaves from different grapevine cultivars and examining mite populations under stereomicroscopic conditions. Several predatory mite species belonging to the family Phytoseiidae were identified based on morphological characteristics including dorsal shield ornamentation, setal arrangement, spermatheca structure, and leg chaetotaxy. Population dynamics revealed considerable seasonal variation among phytoseiid species, with abundance strongly influenced by temperature, relative humidity, and prey availability. Predatory mite populations remained low during periods of extreme heat and low humidity but increased significantly during moderate environmental conditions that favored prey proliferation and reproductive activity. Certain phytoseiid species exhibited close association with tetranychid and eriophyid mite infestations, suggesting their ecological role in suppressing pest mite populations within vineyard habitats. Seasonal peaks of dominant predatory mites generally coincided with increased densities of phytophagous mites, indicating a density-dependent predator–prey relationship. Variations in phytoseiid abundance were also observed among vineyards differing in pesticide application intensity and canopy management practices. Vineyards managed under reduced pesticide input supported higher predator diversity and population stability compared with conventionally treated fields. The study highlights the ecological importance of indigenous phytoseiid mites as natural biological control agents in grapevine agroecosystems subjected to arid environmental stress.