Contact and gustatory effects of Spinosad on inhibition of population build-up of Cryptolestes pusillus (Schon.) (Coleoptera: Cucujidae) after different storage periods in whea

Abstract

The adult population of Cryptolestes pusillus (Schon.) was significantly (P<0.001) reduced after 3-, 6- and 9-months storage periods at different concentrations of Spinosad than those of control medium. Spinosad at all concentrations reduced mean number of larval 5.33±0.72 to 52.00±0.94, 5.67±1.36 to 32.00±1.41 and 2.67±0.54 to 54.33±0.72 after 3, pupal 3.33±1.09 to 26.00±0.94, 3.33±0.72 to 26.00±1.25 and 2.33±0.29 to 16.33±0.27 after 6 and adult 5.33±1.19 to 62.00±0.47, 2.33±0.27 to 72.00±1.25 and 2.33±1.09 to 58.00±1.25 after 9 months storage period. The percent of repulsion (PRC) were always higher in higher concentrations but lower in lower concentrations in every cases. The total population of C. pusillus was 152.00±1.15 and 790.33±2.60 after 1st and 2.67±1.09 and 20.67±3.34 after 2nd generations. Spinosad effectively reduced the survivability and population of C. pusillus of the treated wheat.