author(s)
Ramesh Babu S, Sai Ram Kumar DV, Madhumathi T and Manoj Kumar V

abstract
A laboratory experiment was carried out with insecticide resistance levels of malathion and deltamethrin against different populations of lesser grain borer during 2015-16. Rhizopertha dominica populations showed 3.07, 2.61 and 3.80 folds resistant at LC₅₀ level to malathion (from Ghantasala, Maruteru and Bapatla, respectively) in comparison to laboratory susceptible population. The Jangamaheswarapuram and Nalgonda populations of R. dominica showed 2.10 and 1.80 folds resistant (LC₅₀) to malathion, respectively when compared to their laboratory susceptible population. The Bapatla and Maruteru populations were 1.60 and 1.07 folds resistant at LC₅₀ level to deltamethrin, respectively in comparison with laboratory susceptible population at 72 hours after treatment. The Jangamaheswarapuram population recorded 1.04 (LC₅₀) folds resistant to deltamethrin in comparison to laboratory susceptible population. The Ghantasala and Nalgonda populations were recorded resistance as 0.92 folds at LC₅₀ resistance was recorded as 1.01 and 1.21 folds in comparison with the laboratory susceptible population, respectively.