Control efficacy of spinetoram against Ephestia elutella(Hübner)in cured tobacco leaf warehouse

To effectively control the damage of Ephestia elutella(Hübner)on tobacco leaves during warehouse storage, indoor bioassay was conducted to compare the contact activity to old larvae of Ephestia elutella (Hübner) between spinetoram and β-cypermethrin. Warehouse experiments were conducted to investigate the control efficacy and duration of spinetoram on old larvae of Ephestia elutella(Hübner) at different concentrations. The field control effect of spinetoram on the Ephestia elutella(Hübner)in warehouse was also tested. The results showed that the LC₅₀ and LC₉₀ of spinetoram on old larvae of Ephestia elutella(Hübner)were 0.091 6 and 0.249 2 mg/L, and those of β-cypermethrin were 0.127 4 and 1.854 4 mg/L, respectively. The duration of 80 and 40 mg a.i/L spinetoram was 24 and 18 days and that of 750 mg a.i/L β-cypermethrin was 6 days. Comparing with common β-cypermethrin, spinetoram performed effectively in activity, control efficiency and duration, and its efficacy was verified in warehouses. The old larvae of Ephestia elutella(Hübner)usually climbs out of tobacco leaf bales, therefore spinetoram surface treatment in warehouses could prevent Ephestia elutella(Hübner) pupation and eclosion even not applying to tobacco leaves directly. Spinetoram could significantly reduce population density and control Ephestia elutella (Hübner)in cured tobacco leaf warehouses.