SEASONAL ABUNDANCE AND CONTROL OF SPIRALING WHITEFLY, ALEURODICUS DISPERSUS RUSSELL

Abstract

The spiraling whitefly, Aleurodicus dispersus Russell (Homoptera: Aleyrodidae) is the major pest of different agricultural and horticultural crops in Bangladesh. As a part of this study seasonal abundance of spiraling whitefly and their natural enemies on three ornamental plants and the toxicity evaluation of different chemical insecticides were studied. The population dynamics of spiraling whitefly indicated that peak period of infestation was August to January. Adult whitefly started to infest in May and reached to maximum in August followed by September to January. The whitefly population decreased to zero in the month of April. The month of August to January also showed the availability of the natural enemies’ ladybird beetle, Scymnus sp. (Coleoptera: Coccinellidae) and pupal parasitoid, Encarsia sp. (Hymenoptera: Aphelinidae). Sooty mould infestation on Poinsettia leaves was highest (77%) from August to January. Among the pesticides Profenos Q + Cypermethrin was highly toxic by topical application and exposure to residue and showed 100% mortality within 4 hours after treatment. Bifenthrin, Cypermethrin and Malathion caused 100% mortality within 8 hour by residue on substrate and topical application method. Detergent also showed effective toxicity against A. dispersus in residual application compared to topical application and oral ingestion. Effectiveness of two different methods was assessed by comparing on A. dispersus nymphs and adults. No significant difference was found on the mortality of A. dispersus adult when leaf spraying compared to leaf dipping method. Therefore, for the integrated pest management program, Profenos Q + Cypermethrin, Bifenthrin and Cypermethrin can be used to control the A. dispersus in field condition.