Establishing midgut cell culture from Rhynchophorus ferrugineus (Olivier) and toxicity assessment against ten different insecticides.

Midgut epithelial cell culture was successfully developed from red palm weevil (Rhynchophorus ferrugineus) during this study and named as RPW-1. Optimum conditions for four different commercial media were also worked out to successfully maintain the culture. Grace's medium was found to be the most effective for RPW-1 culturing which resulted in the highest cell density of 7.5 × 10(6) cells/ml after 72 h of cell seeding with 96% cell viability. It was followed by Schneider's medium and TNM-FH medium where cell densities reached up to 7.4 × 10(6) and 5.9 × 10(6) cells/ml, respectively, after 72 h having 91 and 89% cell viability. Comparatively, Media-199 was least effective for RPW-1 cell culturing. As a whole, temperature at 27°C and pH 6.3 were the best for RPW-1 culturing where the highest cell density and maximum cell viability were noted. Individually, Grace's medium, Schneider's medium, TNM-FH medium, and Media-199 produced better results at 27°C, 27°C, 24°C, and 21°C and pH 6.3, 6.4, 5.3, and 7.1, respectively. The toxicity assay and MTT cell proliferation assay revealed that, out of the ten insecticides used in this study, emamectin benzoate was the most toxic insecticide to RPW-1 cells resulting in 92% cell mortality and 74% cell growth inhibition. Dieldrin was the least potent, causing only 19% cell mortality and 18% cell growth inhibition.