Potential worldwide distributions of Neoseiulus californicus and Neoseiulus idaeus (Acari: Phytoseiidae) determined by climatic modelling

ABSTRACT Predatory mites belonging to the family Phytoseiidae are the main agents used globally for the biological control of pest mites, especially predators of the genus Neoseiulus, particularly Neoseiulus californicus (McGregor) and Neoseiulus idaeus (Denmark & Muma). A major target is the ubiquitous mite Tetranychus urticae (Koch). A major factor limiting the effectiveness of natural enemies in biological control programmes is unfavourable climatic conditions at the release site. This study aimed to determine the climatic envelopes of N. californicus and N. idaeus to predict the geographical areas with the highest climatic suitability of each species where its efficacy as a biological control agent would be maximized. Site occurrence data and the associated environmental variables were obtained from pre-existing spatial information found in online databases. These data were analysed using the MaxEnt software to map the geographic areas worldwide most suitable for each species. The climate suitability for N. californicus was especially limited by conditions of high temperature, while limiting factors for N. idaeus were annual variation in temperatures and low annual precipitation. Suitable areas for N. californicus were observed in all five continents, concentrated in latitudes close to the tropics of Cancer and Capricorn. In relation to N. idaeus, suitable areas were observed on four continents and are concentrated in countries close to the Equator, particularly those in the southern hemisphere. N. californicus and N. idaeus have distinct climate suitability areas. The results may be helpful for selecting the predator species for introduction.