Efficacy of Metarhizium anisopliae (Metschnikoff) Sorokin SBI-Ma-SF 5 strain against tomato fruit borer Helicoverpa armigera Hubner (Lepidopetra: Noctuidae)
P. Venkata Koushik
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
P. S. Shanmugam *
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
N. Geetha
ICAR - Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, India.
S. Jeyarani
Agricultural College and Research Institute, Kudumiyanmalai, Tamil Nadu, India.
T. Anand
Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
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.
Keywords: H. armigera, M. anisopliae, pathogenicity, insecticides