Interspecific interaction between Phytoseiulus macropilis and Neoseiulus californicus (Acari: Phytoseiidae) preying on Tetranychus urticae (Acari: Tetranychidae) on rosebush growing in greenhouse

Abstract

Greenhouses provide favorable conditions to grow roses (Rosa spp.) but also for the pest mite Tetranychus urticae Koch (Acari: Tetranychidae). Although chemical control continues to be used against this pest, consumer demand has encouraged research on less aggressive agricultural practices and biological control is now a viable option. The objective of this study was to investigate biological control of the two-spotted mite, in rosebush growing in greenhouse, by Phytoseiulus macropilis (Banks) and Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), individually or in combination. Potted rosebushes (Rosa alba L., Rosaceae) were used in five treatments: 1 -control group, rosebushes only with T. urticae; 2 -rosebushes with T. urticae and N. californicus; 3 -rosebushes with T. urticae and P. macropilis; 4 -rosebushes with T. urticae, N. californicus, and, after 4 weeks, P. macropilis and 5 -rosebushes with T. urticae, N. californicus, and P. macropilis. Biological control was evaluated by counting live mites. The results showed that both predatory mites were efficient in the control of the two-spotted mite on rosebushes cultivated in the greenhouse, either alone or in combination, but, when only P. macropilis was released, this predaceous mite was more efficient than N. californicus, at either low or high prey density, but the N. californicus can survive for longer in the absence of prey or in its low presence, for being a generalist predatory mite.