Efficacy of Beauveria bassiana and Metarhizium anisopliae against tomato leaf miner Phthorimaea absoluta (Meyrick)

The tomato leaf miner Phthorimaea absoluta (Meyrick), earlier known by the scientific name Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most devastating global pests of tomatoes. Using indigenous entomopathogenic fungi can be a promising solution to manage it. Efficacy of EPF isolates on third-instar larvae was carried out in Ethiopia during 2021–2022. Ten larvae were inoculated with conidiaa suspensions with three replications. The result showed that larval mortality was significantly different (p<0.05) among concentrations and isolates. Beauveria bassiana isolates caused 70 to 81% mortality, the lowest LC₅₀ was 1.87×10⁴ to 9.79×10⁴ conidia/ ml; and LC₉₅ was 5.68×10⁸ to 1.10×10⁶ conidia/ml and shortest LT₅₀ was 3.6 to 5.7 days. These were considered highly virulent while Metarhizium anisopliae determined as moderately virulent having 46 to 63% mortality (highest LC₅₀ was 1.36×10⁶ to 4.94×10⁷ and LT₅₀ was 4.3 to 8 days). Results also revealed 1×10¹⁰ conidia/ ml is the most effective dose while 1×10⁶ is the least effective.