Application of mixtures of Metarhizium anisopliae var. acridum and cyhalothrin against the Senegalese grasshopper in Senegal
From 2002 to 2004, three field trials were conducted in Senegal to compare the efficacy of a new biopesticide for grasshopper control, based on the entomopathogenic fungus Metarhizium anisopliae var. acridum Driver & Milner, with mixtures of this biopesticide and cyhalothrin, a widely used pyret...
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| Published in: | International journal of tropical insect science Vol. 28; no. 3; pp. 136 - 143 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Cambridge, UK
Cambridge University Press
01-09-2008
Springer International Publishing Springer Nature B.V |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | From 2002 to 2004, three field trials were conducted in Senegal to compare the efficacy of a new biopesticide for grasshopper control, based on the entomopathogenic fungus Metarhizium anisopliae var. acridum Driver & Milner, with mixtures of this biopesticide and cyhalothrin, a widely used pyrethroid insecticide to control the Senegalese grasshopper Oedaleus senegalensis Krauss. The aim of these trials was to obtain a knockdown effect without compromising the environmental credentials of the biopesticide too much. During the first two trials, 50 ha (2002) and 25 ha (2003) plots were treated with Metarhizium at a rate of 50 g/ha, cyhalothrin at a rate of 40 g/ha, a mixture of Metarhizium at a rate of 25 g/ha and cyhalothrin at a rate of 20 g/ha. For the third trial in 2004, several mixtures of cyhalothrin at a rate of 10 g/ha and Metarhizium at dose rates of 6.25, 12.5 and 25 g/ha were prepared. These mixtures were compared with 50 g/ha of Metarhizium, 40 g/ha of cyhalothrin and 10 g/ha of cyhalothrin on 25 ha experimental plots. The volume application rate for all trials was 1 l/ha. The Metarhizium applications resulted in a slow but long-lasting reduction of grasshopper numbers. By contrast, cyhalothrin produced a rapid reduction, but grasshopper numbers re-increased a few days after application, except in 2003, when grasshopper densities in the surrounding areas were low. The mixtures caused a similarly fast reduction in grasshopper numbers, but this lasted throughout the 3 week post-application assessment period. These trials demonstrated that adding a low dose of a pyrethroid insecticide to a slow-acting biopesticide can increase the speed of population reduction, while retaining the latter's long-lasting effect. A bonus is that the price of the combination is lower than that of each product at the recommended dose rates. Since the insecticide is added at a low dose, its environmental impact is reduced compared with the full-dose insecticide only treatment. |
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| Bibliography: | istex:91D591132CCC6FD66F2E89D5BE599FA8B8565A7D ark:/67375/6GQ-BNDTHGDZ-M ArticleID:07591 PII:S1742758408075917 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1742-7584 1742-7592 |
| DOI: | 10.1017/S1742758408075917 |