Publication Type

Journal Article

Journal Name

Crop Protection

Publication Date

8-1-2002

Abstract

The ovicidal activity of eight isolates of entomopathogenic hyphomycetes was evaluated in the laboratory against Maruca vitrata and Clavigralla tomentosicollis. At a concentration of 1 × 108 conidia ml-1, four isolates (Beauveria bassiana CPD 3 and 10, and Metarhizium anisopliae CPD 5 and 12) were found to be highly pathogenic to eggs of M. vitrata, achieving 89-100% mortality. At a given concentration, three isolates (B. bassiana CPD 9 and M. anisopliae CPD 5 and 12) were highly pathogenic to eggs of C. tomentosicollis, achieving 91-94% mortality. These isolates also caused high larval and nymphal mortality (94-100% in M. vitrata and 91-100% in C. tomentosicollis). M. anisopliae CPD 5 and 12 were selected for testing in cage experiment based on their high pathogenicity to both insect species. Spray application of the fungus in cages at two concentrations, 1 × 106 and 1 × 108 conidia ml-1, was found to significantly reduce the number of emerging borers and bugs. The percentage of pods and seeds damaged was significantly lower in fungal-treated cages than in the control cages. Grain yield per plant also was significantly higher in fungal-treated cages than in the control cages. However, CPD 5 was superior in protecting cowpea plants at a lower inoculum concentration than CPD 12. © 2002 Elsevier Science Ltd. All rights reserved.

Keywords

Clavigralla tomentosicollis, Control, Deferred larval/nymphal mortality, Egg mortality, Maruca vitrata

Download

Share

COinS