Home Sustainable Management of Invasive Pests in Africa Chapter Influence of Predatory Mites, Phytoseiulus longipes Evans. on the Within-Plant Diurnal Migration and Distribution of the Red Spider Mite, Tetranychus evansi, Baker and Pritchard on African Nightshade, Solanum scabrum

Abstract

Understanding the within-plant diurnal migration and distribution of the Red spider mite, Tetranychus evansi Baker and Pritchard, in the presence of the predatory mite Phytoseiulus longipes Evans, on African nightshade, S. scabrum, is critical in developing an Integrated Pest Management (IPM) strategy for the pest. The T. evansi density, day and night cycles, and presence of P. longipes, on the within-plant migration and distribution of T. evansi on African nightshade were hence investigated. The results indicated that T. evansi does not exhibit a circadian migratory movement pattern on S. scabrum at lower densities (50 and 100 mites). However, T. evansi was observed to have a density-dependent collective displacement and distribution to the top of the plant, as densities increased (300 and 600 mites). The presence of P. longipes on the plant enhanced the within-plant migration of T. evansi, even at low densities (50 and 100 mites). However, there was no apparent pattern of migration and movement that was observed within the plant. The increased within-plant movement of T. evansi in presence of the predatory mites and collective displacement of T. evansi at higher densities indicate a potential for developing an IPM strategy using the acaricide treated net, which is discussed further.