Several species of cutworm larvae (caterpillars) may reduce stands by cutting the stems of seedling plants below the cotyledons. Larvae are active at night and hide in the soil during the day. Cutworm damage occurs most frequently following legume cover crops or in reduced tillage systems. They often become established on existing vegetation and feed on emerging cotton once this vegetation has been killed. Destroying all green vegetation at least 21 days prior to planting reduces the likelihood of cutworm attack. For more information visit the Cotton Insects Cutworm Fact Sheet (W032).
Scout for cutworms by counting the number of cut and undamaged plants in 50 feet of row at multiple locations in a field. A pocket knife or garden trowel can be used to dig up larvae from the soil around damaged or adjacent plants to confirm their presence.
Treat when cutworms threaten to reduce stands to less than three plants per row foot. Alternatively, consider treating if 5% or more of plants have been freshly cut. Infestations may be spotty within a field and only require treatment where damage and live cutworms are found.
|Insecticide (Trade Names) for CUTWORMS||Lb Active Ingredient per Acre||Amount Formulation per Acre||Performance Rating|
|acephate 90 (Orthene 90S)||0.72||0.8 lb||6|
|bifenthrin (Brigade 2, Discipline 2, Fanfare 2)||0.05 - 0.1||3.2 - 6.4 oz||6|
|cypermethrin 2.5||0.025 - 0.1||1.3 - 5 oz||8|
|deltamethrin (Delta Gold 1.5)||0.013 - 0.019||1.11 - 1.62 oz||8|
|esfenvalerate (Asana XL 0.66E)||0.03 - 0.05||5.8 - 9.6 oz||8|
|β-cyfluthrin (Baythroid XL 1)||0.0065 - 0.0125||0.8 - 1.6 oz||8|
|γ-cyhalothrin (Declare 1.25)||0.0075 - 0.01||0.77 - 1.02 oz||8|
|λ-cyhalothrin (Warrior II 2.08)||0.015 - 0.02||0.96 - 1.28 oz||8|
|Ζ-cypermethrin (Mustang Max 0.8)||0.008 - 0.012||1.28 - 1.92 oz||8|
- Do not expect Bt cotton to provide adequate control of cutworms, although it provides some protection against small larvae or low infestation levels.
- A near-planting foliar insecticide application may be justified if non-crop vegetation was not burned down at least 21 days prior to planting. This application can be applied in a band over the row.