In the past, pyrethroid insecticides did very well against corn earworm. But in recent years we have seen the decline in the effectiveness of pyrethroids due to the development of resistance in the earworm population. Farmers who rely heavily on these insecticides run the risk of crop loss.
Pyrethroids (IRAC group 3A) can still be used but must be in rotation with materials from other chemical groups, especially groups 5 and 28. Examples of some of these other insecticides include Lannate LV (group 1), Besiege (groups 3A, 28), Blackhawk 36 WG (group 5), Radiant SC (group 5) and Coragen 1.67 SC (group 28).
To prevent the development of insecticide resistance and provide for the best pest control, rotate the insecticide groups in your spray program. Do not rely on a single chemistry (mode of action) otherwise crop loss may occur.
