Effect of Tomato Lycopersicon Esculentum (Mill) Varieties On Development Time Fecundity and Longevity of Red Spider Mite Tetranychus Evansi (Baker & Pritchard)

Abstract

Tomato Lycopersicon esculentum (Mill), is an important source of income to many small scale farmers in Kenya and is a major dietary component. The production of tomatoes is however constrained by several pests with Red spider mite Tetranychus evansi (Baker & Pritchard) being the most important dry season pest in Eastern and Southern Africa. Control of T. evansi has mainly been by chemicals sprays, which has resulted in problem of pest resistance and pollution of the environment. This study was therefore an attempt to look into alternative environmentally friendly ways of controlling T. evansi in tomatoes. To determine the effect of tomato varieties on development time, fecundity and longevity of T. evansi an experiment was conducted in a conviron incubator maintained at 25 ± 2oC ,50-70% relative humidity and photoperiod 12:12 L:D a complete randomized design (CRD) arrangement replicated four times in Kenya Agricultural Research Institute, Njoro, Kenya. The tomato varieties assessed were: Cal J, Onyx, Roma VFN, Riogrande, Money maker, Eden F1, Anna F1, and Wild type. The results showed that the, mortality rate for protonymph, deutonymph and adult stages was highest in Wild type (95%) and lowest in variety Money maker (50%). In addition, the average number of eggs per female mite was significantly higher on variety Money maker (52.4) and Riogrande (48.6), while the least number of eggs was recorded on Wild type (9.1). Tomato variety, Money maker was highly susceptible and Wild tomato was most resistant. Since only eight tomato varieties were evaluated, there is therefore need to evaluate more tomato varieties to identify high yielding and less susceptible varieties that can be recommended to farmers. Varietal resistance could become an integral part of an Integrated Pest Management (IPM) programme.