Check grain heads for larvae. Examine a minimum of 50 plants throughout the field. Sets of 10 heads can be briskly shaken into a bucket or sweep net. Carefully look through the debris for larvae. Corn earworm or fall armyworm will also be found feeding in heads.
During heading, treat when an average of 3-4 or more larvae is found per grain head.
|Insecticide (Trade Names) for SORGHUM WEBWORM||Lb Active Ingredient per Acre||Amount Formulation per Acre||Performance Rating|
|carbaryl (Sevin 80S)||1 - 2||1.25 - 2.5 lb||7|
|carbaryl (Sevin XLR 4)||0.5 - 1||16 - 32 oz||7|
|chlorantraniliprole (Prevathon 0.43 SC)||0.05 - 0.07||14 - 20 oz||9|
|chlorantraniliprole, λ-cyhalothrin (Besiege)||See label||6 - 10 oz||9|
|chlorpyrifos (Lorsban 4, Nufos 4)||0.5 - 1||16 - 32 oz||7|
|chlorpyrifos (Lorsban Advanced 3.775)||0.47 - 0.94||16 - 32 oz||7|
|chlorpyrifos, γ-cyhalothrin (Cobalt Advanced)||See label||16 - 38 oz||7|
|chlorpyrifos, Z-cypermethrin (Stallion)||See label||5 - 11.75 oz||7|
|methomyl (Lannate LV 2.4)||0.45||24 oz||7|
|spinosad (Blackhawk 36% WDG)||0.038 - 0.074||1.7 - 3.3 oz||9|
- Planting early, before mid-May, may help avoid some damage from sorghum webworm.
- Resistance to pyrethroid insecticides is well documented and has been observed in Tennessee. Use of alternative chemistries is generally suggested.