Efficacy of Metarhizium anisopliae (Metschnikoff) Sorokin SBI-Ma-SF 5 strain against tomato fruit borer Helicoverpa armigera Hubner (Lepidopetra: Noctuidae)

Abstract

The polyphagous tomato fruit borer Helicoverpa armigera (Hubner) causes yield loss of 40 – 60 per cent under favourable conditions in Tomato. The farmers rely upon chemical insecticides for its management and its injudicious use leads to unwarranted problems. The use of bio pesticides as a component of integrated pest management is one of the important factor to overcome the pesticides related issue. Among the bio-pesticides entomopathogenic fungi proved their ability against many Lepidopterans. The pathogenicity of Metarhizium anisopliae (Metschnikoff) Sorokin SBI SF Ma 5 strain was studied against tomato fruit borer H. armigera. The median concentration (LC50) of M. anisopliae SBI Ma SF 1 strain was 3.1 x 108 conidia/ml with fiducial limits 2.2 x 107 to 4.2 x 109 conidia/ml. The median lethal time (LT50) value was to be 6.53 days. The SBI SF Ma 5 strain caused 88.83 per cent mortality in second instar H. armigera at 1 x 109 conidia/ml concentration. The decrease in conidial concentration reduced the efficacy of M. anisopliae strain. This strain can be used in the H. armigera management after field evaluation.