Evaluation of susceptibility ofRhyzopertha dominica(F.),Sitophilus granarius(L.) andCryptolestes ferrugineus(Stephens) to spinosad

In this research, we evaluated the toxicity of different concentrations of spinosad to one-day-old adult of Rhyzopertha dominica (F.), Sitophilus granarius (L.) and Cryptolestes ferrugineus (Stephens). The exposure times were 24, 48 and 72 h in all experiments. In contact tests for R. dominica, the maximum mortality rate was achieved with 500 ppm of spinosad after 72 h exposure. The application of 400 ppm of spinosad after 72 h caused maximum mortality in S. granarius. For contact treatment, the complete control of C. ferrugineus was obtained with 500 ppm spinosad at 72 h exposure time. It is possible to recommend 500 ppm of spinosad for complete control of the tested insects through contact application. Estimated LC50 values of spinosad in 72 h after exposure for adults of R. dominica, S. granarius and C. ferrugineus were 1287, 279 and 53.17 ppm, respectively. The results show that C. ferrugineus is the most susceptible insect to spinosad in these experiments.