Whiteflies cause problems in vegetable production on a global scale. The primary worldwide whitefly pest is Bemisia tabaci (Gennadius). Insecticides are commonly used to mitigate the whitefly problem in vegetable crop...Whiteflies cause problems in vegetable production on a global scale. The primary worldwide whitefly pest is Bemisia tabaci (Gennadius). Insecticides are commonly used to mitigate the whitefly problem in vegetable crops. In limited-resource crop production, operator-carried spray applicators are commonly used for pesticide treatments. Three single-nozzle operator-carried spray applicators were assessed for their efficacies for whitefly (B. tabaci) control on summer squash (Cucurbita pepo L.) in Egypt. Each knapsack spray equipment was evaluated with five biorational and conventional insecticides. Counts of whitefly nymphs (first, second, third and fourth instars) on leaf samples were taken on 3, 9, 15 and 21 days after treatments with the insecticides. Nymphal mortality varied about 10% among the three spray equipment treatments. The Economy Micro Ulva sprayer resulted in significantly more nymphal mortality as compared with the Arimitsu sprayer and the CZP-3 sprayer, respectively. All insecticides greatly suppressed the whitefly populations;mean mortality ranged from 73% to 95% for all nymphs combined by day for a given treatment. These results provide pest management practitioners with performance assessment of the three operator-carried pesticide applicators for whitefly management with selected foliar insecticides.展开更多
The sweetpotato whitefly, Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae）, is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator （Coccinella undecimpu...The sweetpotato whitefly, Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae）, is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator （Coccinella undecimpunctata L. [Coleoptera： Coccinellidae]）, a common green lacewing predator （Chrysoperla carnea Stephen [Neuroptera： Chrysopidae]）, and a mirid predator （Macrolophus caliginosus [Wagner] [Hemiptera： Miridae]） were independently made in three vegetable crops （cabbage [Brassica oleracea var. capitata L.], cucumber [Cucumis sativus L.], and squash [Cucurbita pepo L.]） for the management of the sweetpotato whitefly. Approximately 1 million to 2.5 million larvae or nymphs of each predator were released in the vegetable crops during 20 weeks. Whitefly populations were reduced by ≈ 25%-45% during most of the season in each crop where each predator was released. The effect of each predator was similar on whitefly population reduction. Late in the season （October） when whitefly populations were low, generally no benefit was obtained from releasing the predators. Numbers of predators recovered during sampling in all crops were greatest for C. carnea, but this corresponded with the fact that more individuals of this predator were released than any other predator in the experiment. These results help define the utility of these natural enemies for managing B. tabaci in vegetable crops.展开更多
基金supported by Shahre Rey Islamic Azad UniversityNational Natural Science Foundation of China ( 31101495)+1 种基金Commonweal Industry Scientific Researching Fund (201103002)Egyptian Ministry of Agriculture
文摘Whiteflies cause problems in vegetable production on a global scale. The primary worldwide whitefly pest is Bemisia tabaci (Gennadius). Insecticides are commonly used to mitigate the whitefly problem in vegetable crops. In limited-resource crop production, operator-carried spray applicators are commonly used for pesticide treatments. Three single-nozzle operator-carried spray applicators were assessed for their efficacies for whitefly (B. tabaci) control on summer squash (Cucurbita pepo L.) in Egypt. Each knapsack spray equipment was evaluated with five biorational and conventional insecticides. Counts of whitefly nymphs (first, second, third and fourth instars) on leaf samples were taken on 3, 9, 15 and 21 days after treatments with the insecticides. Nymphal mortality varied about 10% among the three spray equipment treatments. The Economy Micro Ulva sprayer resulted in significantly more nymphal mortality as compared with the Arimitsu sprayer and the CZP-3 sprayer, respectively. All insecticides greatly suppressed the whitefly populations;mean mortality ranged from 73% to 95% for all nymphs combined by day for a given treatment. These results provide pest management practitioners with performance assessment of the three operator-carried pesticide applicators for whitefly management with selected foliar insecticides.
文摘The sweetpotato whitefly, Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae）, is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator （Coccinella undecimpunctata L. [Coleoptera： Coccinellidae]）, a common green lacewing predator （Chrysoperla carnea Stephen [Neuroptera： Chrysopidae]）, and a mirid predator （Macrolophus caliginosus [Wagner] [Hemiptera： Miridae]） were independently made in three vegetable crops （cabbage [Brassica oleracea var. capitata L.], cucumber [Cucumis sativus L.], and squash [Cucurbita pepo L.]） for the management of the sweetpotato whitefly. Approximately 1 million to 2.5 million larvae or nymphs of each predator were released in the vegetable crops during 20 weeks. Whitefly populations were reduced by ≈ 25%-45% during most of the season in each crop where each predator was released. The effect of each predator was similar on whitefly population reduction. Late in the season （October） when whitefly populations were low, generally no benefit was obtained from releasing the predators. Numbers of predators recovered during sampling in all crops were greatest for C. carnea, but this corresponded with the fact that more individuals of this predator were released than any other predator in the experiment. These results help define the utility of these natural enemies for managing B. tabaci in vegetable crops.
