Assessment of Beauveria bassiana Sprays for Control of Diamondback Moth (Lepidoptera: Plutellidae) on Crucifers

Abstract

Evaluations of the efficacy and persistence of Beauveria bassiana (Balsamo) Vuillemin for control of the diamondback moth, Plutella xylostella (L.),on cnlcifers were done in growth chambers, the greenhouse, and the field. In growth chamber studies done at 21 or 26°C and 60 or 90%RH, neither temperature nor humidity affected the survival oflarvae, but treatment with fungal spores always provided significantly greater mortality than the control. In 2 grecnhouse 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.

Dose–Response and Age- and Temperature-Related Susceptibility of the Diamondback Moth (Lepidoptera: Plutellidae) to Two Isolates of Beauveria bassiana (Hyphomycetes: Moniliaceae)

“…Mycotrol (with Mycotech CHA as the active ingredient) is labelled for use against insects in several orders, but not including Lepidoptera. However, Shelton et al (1998) found that Mycotrol provided control of P. xylostella larvae resistant to B. thuringiensis on crucifer seedlings and suggested that B. bassiana may be useful as a control agent against insecticide-resistant populations. Vandenberg et al (1998) found that Mycotrol applications on cabbage plants at the 10-12 leaf stage provided effective control of P. xylostella.…”

“…However, Shelton et al (1998) found that Mycotrol provided control of P. xylostella larvae resistant to B. thuringiensis on crucifer seedlings and suggested that B. bassiana may be useful as a control agent against insecticide-resistant populations. Vandenberg et al (1998) found that Mycotrol applications on cabbage plants at the 10-12 leaf stage provided effective control of P. xylostella. However, action thresholds for P. xylostella are much lower on mature plants (Anonymous 1998), when damage to developing vegetative and flowering heads has greater impact.…”

“…In Malaysia, Ibrahim and Low (1993) have shown the potential effectiveness of Beauveria bassiana (Balsamo) Vuillemin and Paecilomyces fumosoroseus (Wize) Brown & Smith against P. xylostella in the field. More recently, Shelton et al (1998) and Vandenberg et al (1998) populations on crucifer seedlings in screenhouses and on larger plants in the field. As a component of a research program to explore the use of B. bassiana for control or management of pest insects, we have developed a laboratory assay protocol to test the efficacy of B. bassi ana and other fungi against P. xylostella.…”

Biological control of the diamondback moth,Plutella xylostella: A review

“…Sporulating cadavers producing Z. radicans or B. bassiana conidia result in similar transmission rates (Furlong and Pell 2001). Various commercial formulations of this fungus significantly suppressed the DBM populations in screened enclosures and the field Vandenberg et al 1998;Becker 1999). …”

“…Several species of fungal pathogens, including Zoophthora radicans (Brefeld) Batko, Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae (Metsch.) Sorokin, Paecilomyces farinosus (Holm ex Gray) Brown & Smith, Fusarium spp., Pandora spp., Erynia spp., Conidiobolus spp., and Scopulariopsis spp., have been isolated from DBM (Vandenberg et al 1998;Cherry et al 2004a;Kirk et al 2004), but few have been studied in detail. Vandenberg et al (1998) reported screening 55 isolates of different fungi including B. bassiana, M. anisopliae, P. farinosus and Fusarium sp.…”