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United States Department of Agriculture

Agricultural Research Service

Title: Effects of Knack and Applaud on Sweetpotato Whitefly Adult and Nymph Honeydew Production Following Laboratory Leaf Dip Treatment

Authors
item Henneberry, Thomas
item JECH, LYNN
item DE LA TORRE, THERESA
item Maurer, Jamie - WCRL TEMP EMPL

Submitted to: Arthropod Management Tests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2002
Publication Date: December 31, 2002
Citation: HENNEBERRY, T.J., JECH, L.J., DE LA TORRE, T.M., MAURER, J. EFFECTS OF KNACK AND APPLAUD ON SWEETPOTATO WHITEFLY ADULT AND NYMPH HONEYDEW PRODUCTION FOLLOWING LABORATORY LEAF DIP TREATMENT. ARTHROPOD MANAGEMENT TESTS. 2002. FIELD AND CEREAL CROPS. L12.ASP

Interpretive Summary: The experiment was conducted in an RCB design of four replications on greenhouse benches. All data were analyzed using ANOVA and LSD mean separation after a significant F test. Four plants infested with first- and second-instar SPW and four uninfested plants, in each case, were dipped in water solutions containing 2,000 or 1,000 ppm of Applaud or 600 or 300 ppm of Knack. Four infested and four uninfested plants dipped in water alone served as checks. For adults, after air-drying, two clip cages with removable plastic bottoms were installed on each of four uninfested Knack-, Applaud-, or water-dip-treated plants. Five SPW adults were placed in each clip cage on each plant. Honeydew was collected for 48 h on the clip cage bottoms. Cages were removed and adults were counted. Cage bottoms with honeydew were frozen. For plants with nymphs dipped in solutions of Applaud, Knack, or water solutions, a leaf-clip cage was installed on one leaf of each of four plants in each treatment category. Cages were positioned to enclose living nymphs. Honeydew was collected for 48 h. Cages were removed and nymphs were counted. The removable cage bottoms with honeydew were held in a freezer. After 48 additional hours, i.e., 96 h after treatment, two leaf-clip cages, one per leaf, were reinstalled on leaves of uninfested or nymph-infested Applaud-, Knack-, or water-treated plants. Adults were placed in cages on uninfested plants as described above. Honeydew was collected for 48 h in all leaf cages. Cages were removed, living and dead adults and nymphs were counted, and honeydew collection clip-cage bottoms were frozen. Honeydew was washed from all leaf-cage bottoms with 3 ml of warm deionized water and frozen in 15-ml plastic test tubes. Frozen honeydew samples were lyophilized and reconstituted in 125 ml of deionized water. Trehalose, melezitose, glucose, fructose, and sucrose in the samples were determined using high performance liquid chromatography and sampled sugars were quantified by comparison with peak areas of known sugar standards.

Technical Abstract: The experiment was conducted in an RCB design of four replications on greenhouse benches. All data were analyzed using ANOVA and LSD mean separation after a significant F test. Four plants infested with first- and second-instar SPW and four uninfested plants, in each case, were dipped in water solutions containing 2,000 or 1,000 ppm of Applaud or 600 or 300 ppm of Knack. Four infested and four uninfested plants dipped in water alone served as checks. For adults, after air-drying, two clip cages with removable plastic bottoms were installed on each of four uninfested Knack-, Applaud-, or water-dip-treated plants. Five SPW adults were placed in each clip cage on each plant. Honeydew was collected for 48 h on the clip cage bottoms. Cages were removed and adults were counted. Cage bottoms with honeydew were frozen. For plants with nymphs dipped in solutions of Applaud, Knack, or water solutions, a leaf-clip cage was installed on one leaf of each of four plants in each treatment category. Cages were positioned to enclose living nymphs. Honeydew was collected for 48 h. Cages were removed and nymphs were counted. The removable cage bottoms with honeydew were held in a freezer. After 48 additional hours, i.e., 96 h after treatment, two leaf-clip cages, one per leaf, were reinstalled on leaves of uninfested or nymph-infested Applaud-, Knack-, or water-treated plants. Adults were placed in cages on uninfested plants as described above. Honeydew was collected for 48 h in all leaf cages. Cages were removed, living and dead adults and nymphs were counted, and honeydew collection clip-cage bottoms were frozen. Honeydew was washed from all leaf-cage bottoms with 3 ml of warm deionized water and frozen in 15-ml plastic test tubes. Frozen honeydew samples were lyophilized and reconstituted in 125 ml of deionized water. Trehalose, melezitose, glucose, fructose, and sucrose in the samples were determined using high performance liquid chromatography and sampled sugars were quantified by comparison with peak areas of known sugar standards.

Last Modified: 7/28/2014
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