3.3. Larva bioassays
Laboratory larval bioassays with 1 ppm temephos for both species
resulted in 100% mortality for the first ten months. Survival of
larvae was observed after ten month (Fig. 2). In the field where
1 ppm concentration was gradually decreased with usage of water,
100% mortality was observed only for the first four months, >50%
mortality for next two months and 0% mortality was observed
eight months after the application of temephos (Fig. 3).