Assessment of Beauveria bassiana sprays for control of diamondback moth (Lepidoptera: Plutellidae) on crucifers
1998
Vandenberg, J.D. | Shelton, A.M. | Wilsey, W.T. | Ramos, M.
Evaluations of the efficacy and persistence of Beauveria bassiana (Balsamo) Vuillemin for control of the diamondback moth, Plutella xylostella (L.),on crucifers were done in growth chambers, the greenhouse, and the field. In growth chamber studies done at 21 or 26 degrees C and 60 or 90% RH, neither temperature nor humidity affected the survival of larvae, but treatment with fungal spores always provided significantly greater mortality than the control. In 2 greenhouse trials, 1 application of B. bassiana spores suspended in water or oil significantly reduced larval populations compared to controls. In a field trial, both treatment and insect stage at treatment (2nd and 3rd to 4th instars) significantly affected larval survival. The fungus formulated as a wettable powder at 2 rates and as an emulsifiable suspension at a high rate, provided significant reductions in larval counts. Two applications of the wettable powder at the higher rate resulted in lower larval counts than did a single application. Two applications (but not 1) of wettable powder at the lower rate resulted in significantly lower counts of 2nd instars but not 3rd to 4th instars. Both treatment and time affected both the persistence of viable B. bassiana spores on leaves and the retention of efficacy of treated leaves for P. xylostella larvae. These trials indicate the potential for including B. bassiana in an overall management program for P. xylostella.
显示更多 [+] 显示较少 [-]