Provisioning of prey mites improves Tetranychus urticae control with Neoseiulus californicus

Abstract: Spider mites are major pests of different crops worldwide, among the two-spotted spider mite, Tetranychus urticae is the most important, as it attacks many cultivated crops in many different geographic areas. There are different commercially available natural enemies for augmentative biocontrol of these pests, of which the Phytoseiid mites Phytoseiulus persimilis and Neoseiulus californicus are the most important. Earlier studies have revealed that preventive releases of predatory mites result in better pest control, but as P. persimilis is a specific predator of tetranichid and N. californicus has a strong preference for mite pests, it is difficult to release them preventively. Thus, in our study, we hypothesized whether the provisioning of a suitable prey mite would allow preventive releases of N. californicus, ultimately allowing effective T. urticae control. We conducted two experiments of which the first aimed at evaluating the establishment of N. califonicus when feeding on different prey mites and revealed that Carpoglyphus lactis was the most suitable. The second experiment, simulated preventive and curative releases of N. californicus with or without provisioning of C. lactis and the preventive release of N. califonicus combined with supplemental releases of C. lactis provided best and excellent T. urticae control.