Field evaluation of microbial insecticides against fall armyworm, Spodoptera frugiperda (smith) and corn earworm, helicoverpa zea (boddie) (lepidoptera: Noctuidae), in maize

Abstract

Commercial formulations of two entomopathogenic fungi (Metarhizium anisopliae Metschnikoff and Beauveria bassiana Balsamo) and two strains of Bacillus thuringiensis (B. thuringiensis var. kurstaki and B. thuringiensis var. aizawai) were evaluated against S. frugiperda and H. zea in two fields in the Yucatan Peninsula. In both locations, M. anisopliae and B. bassiana had similar efficacy (Davis and Williams scale for final damage of 1.2–1.3 at Becal and 1.7–2.6 at Muna) to that of emamectin benzoate (damage level 1.4 in Becal and 2.0 in Muna) on suppressing leaf damage by S. frugiperda. These fungal-based insecticides also caused a decrease in the ear damage by H. zea. Grain yield of plots treated with these fungal-based insecticides (5900–7500 kg ha⁻¹) was similar to that treated with emamectin benzoate (7400–7500 kg ha⁻¹).

Keywords:

• Entomopathogenic microorganisms
• Lepidoptera larvae
• maize pests

Acknowledgment

The authors thank CONACYT for the postgraduate scholarship to Walter Torres-Cab.

Disclosure statement

No conflict of interest has been reported by the authors.

Additional information

Funding

This study was supported by Tecnológico Nacional de México, grant 9697.20-P to Esaú Ruiz-Sánchez.