Hassan Ansari-Shiri, Myron P Zalucki, Yaghoub Fathipour
The cyclamen mite, Phytonemus pallidus Banks, is a major threat to strawberries, causing significant damage. Chemical control is challenging due to its hidden feeding habits. Therefore, emphasizing host plant resistance is crucial, particularly in the tritrophic system. In the present study, the compatibility of the predatory mite Neoseiulus californicus McGregor with resistant and susceptible strawberry cultivars was evaluated for the management of the cyclamen mite, P. pallidus, under laboratory conditions. Leaves from two greenhouse-adapted cultivars, Sabrina (susceptible) and Albion (resistant), and two field-adapted cultivars, Gaviota (susceptible) and Paros (resistant), were used to assess predator performance. The fecundity, intrinsic rate of increase (r), and finite rate of increase (λ) of N. californicus were significantly greater on the susceptible greenhouse- and field-adapted cultivars than on the corresponding resistant cultivars. Predation rate did not differ significantly between the greenhouse cultivars but was significantly higher on the resistant field cultivar Paros than on the susceptible cultivar Gaviota. Although Paros reduced the predator's population growth potential by approximately 19%, this effect was compensated by a 21% increase in predation rate. In contrast, Albion caused only a slight reduction (5%) in predator population growth while substantially suppressing cyclamen mite populations (20%). These findings indicate that N. californicus remains an effective biological control agent on resistant strawberry cultivars, particularly Albion, demonstrating good compatibility between host plant resistance and biological control. The combined use of resistant cultivars and N. californicus therefore represents a promising strategy for the sustainable management of cyclamen mite in strawberry production systems.