EFFECT OF PLANT GROWTH STAGE ON THE POPULATION OF WHITEFLY Bemisiatabaci UNDER GLASSHOUSE CONDITIONS

Abstract

The infestation of the whitefly (WF), Bemisiatabaci (Genn.) (Homoptera: Aleyrodidade) has caused losses in greenhouse crops in tropical and subtropical regions. The pest sucks plant sap, thereby weakening plants and causing shoot and leaf distortion (Brown et al, 1995). More significantly whiteflies secrete large amount of honeydew onto leaves and fruit, which in turn gets colonized by sooty molds, thus deteriorating the quality of greenhouse vegetables such as chilli, eggplant, tomato and okra.The first documentation of whiteflies in Malaysia was in 1935, albeit not as an economic pest, on chilli (C. annuum), soybean (Glycine max) and okra (A. esculentus) in the lowlands of Malaya. It has since been seen in numerous locations in Peninsular Malaysia on angled loofah (Luffaacutangula), brinjal (S. melongena), cucumber (Cucumissativus), french bean (Phaseolus vulgaris) and longbean (Vignasesquipedalis) (Syed et al, 2000). With its recognition as a polyphagouspest there is aconsiderable rise in the research dedicated to the whitefly (Inbar&Gerling. 2008). A key factor that determines the selection of the host plant for whitefly feeding is plant age (Horowitz. 1986), a demonstration of which was the increase of B. tabaci populations in pumpkin, bean, zucchini and other plants as they aged (Simmons, 1999). This study aims to better understand the relation between plant growth stages and whitefly populations