author(s)
G Bindu Bhargavi, K Manjula, A Ramakrishna Rao and B Ravindra Reddy

abstract
The liquid formulations of Nomuraea rileyi, an important entomopathogenic fungus were prepared by using two vegetable oils and two mineral oils viz., olive oil, rice bran oil, liquid paraffin oil, heavy grade mineral oil. N. rileyi spore mass was harvested from culture plates and mixed to autoclaved test oils in the proportions of 0.1g (0.5 x 10⁸ spores/0.1 g) and 0.2g (0.1 x 10⁹ spores/0.2 g) per 100ml. Triton-X 100, a wetting agent was also used in two different concentrations i.e., 0.05% and 0.1% for all four test oils. The pathogenicity of N. rileyi conidia was studied at monthly intervals up to 5 months and mortality percentages of third instar larva of S. litura was calculated.Among the 16 oil based formulations of N. rileyi tested in the laboratory, based on the better performance, eight were selected for field evaluation against S. litura in Rabi groundnut. In all the plots in which treatments are imposed by spraying lab selected oil formulations of N. rileyi, the defoliation was significantly less when compared to untreated control treatment. The lower percentages leaf damage of 26, 25.87 and 21.61 with respect to S. litura at 5, 10 and 20 DAT was recorded with rice bran oil with 0.2g spores and 0.1ml triton-X 100 oil formulation. In other formulations also leaf damage was considerably lower at 20 DAT. The leaf damage by S. litura was 22-25 per cent in the formulations against 49 per cent in the untreated control at 20 days after treatment.