Plants and leaf characteristics influencing the Predaceous mite Kampimodromus aberrans (Acari: Phytoseiidae) in habitats surrounding vineyards

Abstract

We sampled phytoseiid mites (densities, diversity, and age structure) on several plants located in four uncultivated areas surrounding vineyards over 3 yr to determine how leaf structure affects populations. The plant composition of these areas greatly influenced the numbers and species of phytoseiids present. The relationships between leaf structure (trichome, pollen densities, number, and structure of domatia, leaf surface) and Kampimodromus aberrans (Oudemans) densities also were studied. The frequency of occurrence and the abundance of K. aberrans per cm2 were correlated to high trichome densities. A complex phylloplane (many hairs and shelters or domatia) could confer a competitive advantage to K. aberrans over other phytoseiid mite species. The number and the rating of domatia were important to K aberrans development; high proportions of immatures were observed only on plants with these structures. Pollen densities were significantly correlated to trichome densities; domatia structure had only a somewhat lesser effect. Our study shows that dense trichome and pollen levels are favorable to the development of K. aberrans populations and add perspective on the influence of domatia on this important predaceous mite.