INFLUENCE OF ENDOSULFAN ON BEMISIA-TABACI (HOMOPTERA, ALEYRODIDAE) POPULATIONS, PARASITISM, AND LETTUCE INFECTIOUS YELLOWS VIRUS IN LATE-SUMMER PLANTED CANTALOUPE

Studies were conducted to evaluate the effectiveness of endosulfan in reducing the incidence of lettuce infectious Bellows virus (LIYV) in l ate-summer planted cantaloupe, Cucumis melo L., through reduction of s weet potato whitefly, Bemisia tabaci (Gennadius), densities. Counts of B. tabaci adults and immatures and of a native parasitoid of B. tabac i, Eretmocerus sp. near californicus Howard (Hymenoptera: Aphelinidae) were lower in treated plots than those in untreated plots for the dur ation of the trial. Despite lower populations of B. tabaci, LIYV was n ot significantly different between treatments, reaching 48% in treated and 40% in untreated plots. B. tabaci emigrated out of treated plots which may have contributed to the spread of LIYV. Sooty mold growth on fruit contaminated with B. tabaci-produced honeydew was present on on ly 0.4% of the melons in treated plots, but on 29% of the melons in th e untreated plots. B. tabaci population dynamics on cantaloupe is disc ussed with regard to control strategies and LIYV epidemiology.