The feeding and searching behaviour of two species of phytoseiid mites, Phytoseiulus persimilis Athias-Henriot and Amblyseius degenerans (Berlese), at different prey densities (Acarina: Phytoseiidae)

Abstract

Detailed observations were made on various components of the predatory behaviour of each instar of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, in the laboratory. These observations revealed that many aspects of the feeding and searching behaviour of these predators are dependent on the prey density to which they are exposed. Differences between the two species are described and it is concluded that P. persimilis has a greater ability to modify its behaviour in relation to prey conditions than A. degenerans. The results explain why P. persimilis has a lower capacity for prey and lower prey requirements for survival, development, and reproduction than A. degenerans, and also the nature of the functional and numerical responses to prey density of the two species.