Spatio-temporal distribution of mite pests and predatory mites in strawberries

Strawberry production in the U.S. is challenged by severe two-spotted spider mite (TSSM, Tetranychus urticae) infestations. In addition, cyclamen mite (Phytonemus pallidus) infestations are frequently reported from strawberry plantings in VA and NC. For instance, since 2020, a nursery in eastern NC and multiple strawberry fields in southeastern Virginia have reported severe infestations with cyclamen mites in three-consecutive seasons. Mite control can be very difficult. The development of pesticide resistance is a major concern and there is an increasing need to reduce pesticide applications. Additionally, not all miticides that suppress TSSM are effective against cyclamen mites with few options available for control of this mite. Predatory mites can successfully control TSSM and suppress cyclamen mites. Spatial and temporal distribution patterns can be helpful to identify pest distribution and predatory mite performance yet are often overlooked because of analysis complexity. We identified temporal and spatial distribution patterns of TSSM and cyclamen mites in strawberry plantings using geostatistical techniques. We analyzed spatial dependence by using the spatial variation in direction and distance between samples resulting in the prediction of spatial phenomena at unsampled locations. In spring 2022, data on the number of TSSM and cyclamen mites per leaf collected at multiple geo-referenced locations within two strawberry plantings were used to generate distribution maps for pest and Neoseiulus californicus. Data from this study offer the potential to identify areas within the field indicating early mite infestations. The adequate implementation of this technology will allow the reduction of pesticide applications.