• Insecticides for Whitefly Control in Cantaloupes

      Umeda, K.; Fredman, C.; Fredman, R.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1996-08)
      Several experimental insecticide treatment combinations were evaluated and demonstrated very good efficacy against Bemisia argentifolii [silverleaf whitefly (WF) also known as sweetpotato WF, B. tabaci]. Adults and immatures were most effectively reduced compared to the untreated check by pyriproxyfen (S-71639, Valent) treatments and fenpropathrin (Danitol®) plus acephate (Orthene®). CGA-215944 (Ciba) plus fenoxycarb (Ciba) treatments compared favorably with many of the pyrethroid combination treatments. Registered products esfenvalerate (Asana®), endosulfan (Thiodan®), cypermethrin (Ammo®), naled (Dibrom®), and oxydemeton-methyl (Metasystox-R®) complemented many of the combination treatments to reduce WF relative to the untreated check
    • Late Season Biological Control of Whiteflies in Fall Cantaloupe Using Formulations of Beauveria Bassiana

      Knowles, Tim C.; Jaronski, Stefan T.; McGuire, Jerry; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1996-08)
      Beauveria bassiana is a naturally occurring fungal disease of insects that has been shown to be an effective biological control against whiteflies in cotton and vegetable crops. Six treatments were initiated in drip irrigated fall cantaloupe on October 2, and repeated on October 9 and 23. The six treatments consisted of 1) a check or unsprayed plot; 2) 0.5 lb. Mycotrol WP/acre; 3) 1 Ib. Mycotrol WP /acre; 4) 1 pt. Mycotrol ES/acre; 5) 0.5 lb. Mycotrol WP /acre + pyrethroid tank mix; and 6) 12 oz. Naturalis-L/acre. Under moderate to light sweetpotato whitefly pressure, the Mycotrol formulations provided significant control (68-79%) compared to unsprayed check plots, and were superior to Naturalis-L formulation whose effects were relatively short lived. Mycotrol WP applied in three applications at the labeled rate of 1 lb. product/acre had the cumulative effect of maintaining adult whitefly leaf counts below the currently recommended economic threshold of 3 per leaf at 28 days after treatment initiation, under the conditions of this study.
    • Whitefly Control with Foliar Insecticides Following Imidacloprid in Cantaloupes

      Umeda, Kai; Fredman, Chris; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1996-08)
      Foliar insecticides for whiteflies (Bemisia sp., WF) were applied as a supplementary control measure at 6 weeks after treatment with imidacloprid (Admire®) at planting time of melons. Beauveria bassiana fungus spores (Mycotrol®), pyriproxyfen (S-71639, Valent), and azadirachtin (Align®) are non-conventional insecticides that could be safer on beneficial parasites and predators. The number of eggs and nymphs counted at all rating dates for all treatments were not significantly different from the foliarly untreated check. Mycotrol treated melons showed higher number of nymphs following the second application. The Align treatment tended to exhibit higher number of nymphs after two applications. The addition of an adjuvant did not appear to enhance pyriproxyfen efficacy.