Vol. 12, Issue 3 (2023)

Author(s):
Chetna Khandekar, Dr. YK Yadu and Ashithosh Mohanan

Abstract:
This experiment was conducted in the laboratory of the Entomology Department at the College of Agriculture, IGKV, Raipur (C.G.) during 2018–19. The eggs and larvae of S. litura were collected from the soybean field, and rearing was done in laboratory conditions at a temperature of 20–32 °C and a relative humidity of 40–75%. After the multiplication of insects, second and third-instar larvae were used for the further study. Leaf dipping method was used for the evaluation of the efficacy of microbial insecticides and plant product. Before making the dipping solutions, the spores of different microbial insecticides were counted in the colony counter metre. Fresh leaves of soybean were collected from untreated plots and washed properly. These leaves were then dipped in the solutions of different microbial insecticides and plant product (Neemban) for 10 minutes. In each petri dish, five treated leaves and five untreated larvae were placed in the laboratory at ambient environmental conditions. A total of 180 larvae, i.e., 45 larvae in each repetition, were taken in the different petridishes. The observations were recorded after every 24 hours, i.e., 24hrs, 48hrs and 72hrs. The statistical analysis for the percent mortality of S. litura was calculated as per Abbott's formula. The cumulative mortality of larvae was recorded up to three days in every 24-hour interval, and then the mean percent mortality was computed.