Artificial microstructure encouraging the colonization of the predacious mite, Neoseiulus californicus (McGregor)(Acari: Phytoseiidae)

Abstract

In order to develop an artificial habitat encouraging the colonization efficiency of phytoseiid mites on fruit trees, we conducted choice experiments with a predacious phytoseiid mite, Neoseiulus californicus, using 22 types of artificial microstructures (3 cm×3 cm, less than 1 cm thick) in the laboratory. Large numbers of N. californicus preferred fine-textured urethane foam and a shading net, although the locations where N. californicus settled on each microstructure were different: more than 80% of N. californicus adults preferred being ‘on a plastic board under fine-textured urethane foam’, while more than 95% preferred being ‘on and in the shading net itself’. With respect to their practical use on fruit trees, shading nets are useful, because their size and thickness can be changed easily and they are also effective tools to transfer phytoseiid mites to trees with low phytoseiid densities. Thus, shading nets were considered to be the best candidate for an artificial habitat of phytoseiid mites on fruit trees.