Selection of Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok. for the control of the mite Mononychellus tanajoa (Bondar)

Rodrigo Soares Barreto,Manoel Guedes Corrêa Gondim Jr,José Vargas De Oliveira,Edmilson Jacinto Marques

doi:10.1590/s0103-90162004000600015

Rodrigo Soares Barreto, Manoel Guedes Corrêa Gondim Jr + Show 2 more

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https://doi.org/10.1590/s0103-90162004000600015

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Journal: Scientia Agricola	Publication Date: Dec 1, 2004
Citations: 18	License type: cc-by

Affiliation: Universidade Federal Rural de Pernambuco

Abstract

The green mite, Mononychellus tanajoa (Bondar) (Acari: Tetranychidae), is considered to be one of the key pests in cassava, Manihot esculenta Crants, leading to considerable field losses. In this study, ten Beauveria bassiana (Bals.) Vuill. and ten Metarhizium anisopliae (Metsch.) Sorok. isolates were evaluated with regard to their potential as biological control agents against adult M. tanajoa females. The total mortality percentage of M. tanajoa caused by B. bassiana ranged from 13.0 to 97.0%, with confirmed mortality rates extending from 9.0 to 91.0% and LT50 varying from 4.2 to 17.0 days. The M. anisopliae isolates showed total mortality percentages ranging from 12.0 to 45.0% with confirmed mortality rates extending from 8.0 to 45.0%, and LT50 varying from 8.6 to 19.8 days. Lethal Concentrations (LC50) of 3.93 × 10(6) conidia mL-1 and 7.44 × 10(8) conidia mL-1 were determined for B. bassiana and M. anisopliae, respectively. B. bassiana isolate 645 was the most efficient, being an alternative for use in biological control programs against the cassava green mite.

Highlights

Brazil is one of the world’s greatest cassava (Manihot esculenta Crantz) producers, with an annual yield of over 20 million tons, which places this crop among the main agricultural products explored in the country (FNP Consultoria e Comércio, 2002)
Lethal Concentration Estimation The 645 B. bassiana and CG 321 M. anisopliae isolates, identified as the most pathogenic in the previous stage based on mortality and smaller LT observed against the cassava green mite, were used at the concentrations of 1 × 104, 105, 106, 107, and 108 conidia mL-1 for Lethal Concentrations (LC) determination
The total mortality percentage caused by B. bassiana isolates varied from 13.0 to 97.0%; confirmed mortality varied from 9.0 to 91.0%, and LT50 values ranged from 4.2 to 17.0 days

Summary

Introduction

Brazil is one of the world’s greatest cassava (Manihot esculenta Crantz) producers, with an annual yield of over 20 million tons, which places this crop among the main agricultural products explored in the country (FNP Consultoria e Comércio, 2002). Within this context, Odongo et al (1998) mentioned the potential for controlling M. tanajoa using the entomopathogenic fungus Hirsutella thompsonii Fisher, as well as the use of Entomophthora spp., Beauveria bassiana (Bals.) Vuill., and Metarhizium anisopliae (Metsch.) Sorok.

Results

Conclusion