Protein Levels in Metarhizium anisopliae (Metschn.) Sorokīn Infested Tomato Fruit Borer Helicoverpa armigera Hubner (Lepidoptera; Noctuidae)
R. Yamini
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, India.
P. S. Shanmugam *
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, India.
M. Murugan
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, India.
N. Geetha
ICAR-Sugarcane Breeding Institute, Coimbatore 641 003, India.
P. Meenakshi
ICAR – National Bureau of Agricultural Insect Resources, Bengaluru 560 024, India.
A. Kandan
ICAR – National Bureau of Agricultural Insect Resources, Bengaluru 560 024, India.
*Author to whom correspondence should be addressed.
Abstract
The tomato fruit borer, Helicoverpa armigera Hubner (Lepidoptera; Noctuidae), is responsible for significant yield losses in tomatoes and employing chemical pesticides leads to unwarranted environmental issues. The use of entomopathogens in tomato Integrated Pest Management reduces the dependency on chemical insecticides. The green muscardine fungus Metarhizium anisopliae is an important entomopathogen used worldwide against many lepidopteran and coleopteran pests. The potential of M. anisopliae depends on its ability to overcome the host defence mechanisms. The immune system in the H. armigera in response to M. anisopliae infection can be revealed using protein analysis. The order of efficacy of four M. anisopliae strains against second and fourth instar H. armigera under laboratory conditions was ICAR SBI VS 8 > ICAR SBI I >ICAR SBI S69 > ICAR SBI MA4. The protein concentration increased with a decrease in M. anisopliae strain concentration in the second and fourth H. armigera larvae. The highly virulent ICAR SBI VS 8 infested H. armigera showed a decline in protein concentration up to 168 h (14.99 mg/g). The second and fourth instar H. armigera, showed similar protein concentration trends in response to M. anisopliae infestation. The virulent ICAR SBI VS 8 strain can resist the host insect's immune response and cause infection to the H. armigera.
Keywords: H. armigera, M. anisopliae, protein, median lethal concentration