HOST RELATED VARIATION IN CARBOXYLESTERASE ACTIVITY OF THE WHITEFLY Bemisia tabaci (GENNADIUS) POPULATIONS ON CABBAGE AND GARDEN EGG

The sweet potato whitefly Bemisia tabaci is a major pest of several crops including vegetables in Ghana. In this study, the effect of two host crops, cabbage and garden egg on B. tabaci carboxylesterase (CaE) activity, a major insecticide detoxification enzyme was observed in three vegetable growing sites. The B. tabaci populations on cabbage had higher CaE activity levels compared with garden egg populations. This observed difference in enzyme activity of B. tabaci on hosts was significant in two of the three sampled sites. The CaE activity levels of B. tabaci from the sampled sites also varied and were also significant. There was also a significant host site interaction effect on the CaE activity of B. tabaci populations. This provides useful information for integrated pest management formulation for each host crop in these specific vegetable growing areas.