Spider mite host plant resistance traits improve the predatory performance of Phytoseiulus persimilis on cucumber, despite negative life history impacts

Abstract Tritrophic interactions can provide important insights for improving the efficacy of pest control programs. We studied three cucumber, Cucumis sativus, cultivars for their effects on the life table and predation parameters of the predatory mite, Phytoseiulus persimilis Athias–Henriot, when feeding on eggs and nymphs of the two-spotted spider mite (TSSM), Tetranychus urticae Koch. These cultivars were TSSM-susceptible (cv. Vida), semi-resistant (cv. Sultan), and resistant (cv. Caspian). Under laboratory conditions, the intrinsic rate of increase (r) and net reproductive rate (R0) of P. persimilis was significantly higher on the susceptible cultivar than on the resistant ones. In contrast, the age-stage-specific predation rate (cxj), net predation rate (c0) and finite predation rate on the resistant cultivar were all higher than on the semi-resistant or susceptible ones. Although the susceptible cultivar produced the most favorable life table parameters for P. persimilis, the resistant cultivar supported more P. persimilis individuals and had higher levels of predation on TSSM. Resistant cultivars in combination with P. persimilis can improve control of TSSM on cucumber, despite some negative life history impacts on the predator.