Corn seed-Corn earworm (sweet corn only)

Helicoverpa zea

Pest description and crop damage Eggs are laid on corn silks. Young caterpillars feed on silks and move into ear tips. Large older caterpillars are large green, brownish, or reddish worms that feed on on silk and kernels of the ear. Caterpillar color can be highly variable even within a single field. Corn earworm must be controlled before larvae bore into corn ear.

Management-chemical control

  • alpha-cypermethrin (Fastac EC) at 0.011 to 0.025 lb ai/a. REI 12 hr. PHI 30 days grain & stover; 60 days forage. Retreatment interval 3 days. Do not exceed 0.075 lb ai/a per season. (Group 3A)
  • azadirachtin (Neemix 4.5 and other products) at 0.02 to 0.04 lb ai/a. PHI 0 days. REI 4 hr. Begin applications at first sign of infestation. Some formulations are OMRI-listed for organic use. (unidentified group)
  • beta-cyfluthrin (Baythroid XL) at 0.013 to 0.022 lb ai/a. PHI 0 days for green forage, 21 days for grain or fodder. Do not exceed 0.088 lb ai/a per season. REI 12 hr. (Group 3A)
  • bifenthrin (Bifenthrin2EC, numerous products) at 0.033 to 0.1 lb ai/a. PHI 30 days. Do not exceed 0.3 lb ai/a per season. This product is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. Highly toxic to bees. Extremely toxic to fish and aquatic invertebrates. REI 12 hr. (Group 3A)
  • bifenthrin/zeta-cypermethrin (Hero) at 0.04 to 0.1 lb ai/a. PHI 30 days for grain & or stover; 60 days forage. REI 12 hr. Do not graze for 30 days after treatment. REI 12 hr. Do not exceed 0.4 lb ai/a per season. This product is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. (Group 3A)
  • chlorantraniliprole/lambda-cyhalothrin (Voliam Xpress) at 0.049 to 0.088 lb ai/a. PHI 21 days. REI 24 hr. Do not exceed a total of 0.3 lb ai of Voliam Xpress or 0.12 lb ai of products containing lambda-cyhalothrin or 0.2 lb ai of products containing chlorantraniliprole foliar products per acre per growing season. (Groups 28 and 3A)
  • chlorpyrifos (Lorsban 4E; other products) at 0.75 to 1 lb ai/a. If crop residue is to be fed to livestock, PHI 21 days grain or ears. REI 24 hr. Do not exceed 3 lb ai/a per season. (Group 1B)
  • chlorpyrifos+gamma cyhalothrin (Cobalt) at 0.13 to 0.26 lb ai/a. PHI 21 days. PHI 14 days grazing or silage; 21 days for grain or ears. REI 24 hr. Do not exceed 3 applications or 2.5 lb/a per season. This product is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. (Groups 1B and 3A)
  • chlorantraniliprole (Coragen) at 0.045 to 0.065 lb ai/a. PHI 14 days. REI 4 hr. Do not exceed 0.2 lb ai/a or 4 applications per season. (Group 28)
  • chlorantraniliprole + lambda cyhalothrin (Besiege) at 0.049 to 0.088 lb ai/a. PHI 21 days. REI 24 hr. Do not exceed 0.012 lb ai/a lambda-cyhalothrin or 0.12 lb ai/a chlorantraniliprole per season. Retreatment interval 7 days. (Groups 28 and 3A)
  • esfenvalerate (Asana XL; other products) at 0.03 to 0.05 lb ai/a. PHI 21 days. REI 12 hr. Do not exceed 0.25 lb ai/a per season. Not for use on sweet corn seed. (Group 3A)
  • flubendiamide (Belt SC) at 0.0625 to 0.094 lb ai/a. PHI 28 days. If crop residue is to be fed to livestock, PHI: 1 day, green forage and silage; 1 day, sweet corn; 28 days, grain or stover. REI 12 hr. Do not exceed 0.375 lb ai/a per season. (Group 28)
  • lambda-cyhalothrin (numerous products) at 0.015 to 0.025 lb ai/a. PHI 1 day for grazing or forage as feed; 21 days for harvest or as feed treated corn fodder or silage. REI 24 hr. Do not exceed 0.12 lb ai/a per season. Not all products are registered for use on sweet corn seed. (Group 3A)
  • methomyl (Lannate LV; other products) at 0.225 to 0.45 lb ai/a. PHI 3 days forage; 21 days for ears or stover. REI 48 hr. Do not exceed 2.25 lb ai/a per season. Not for use on sweet corn seed. (Group 1A)
  • permethrin (numerous products) at 0.1 to 0.2 lb ai/a. PHI 0 days for forage harvest, 30 days for grain or fodder. REI 12 hr. Do not exceed 0.6 lb ai/a per season. Allow at least 6 days between applications. Applications for corn earworm should be made from before silking to brown silk formation. (Group 3A)
  • spinetoram (Radiant SC) at 0.023 to 0.047 lb ai/a. PHI 1 day grain harvest;. If crop residue is to be fed to livestock, PHI is 3 days for forage or fodder. REI 4 hr. Do not exceed 0.281 lb ai/a per season. Limit 6 applications. For corn earworm at silking, do not make applications less than 2 days apart, and do not make more than two consecutive applications of Group 5 insecticides. This product is toxic to bees exposed to treatment for 3 hours following treatment. Do not apply this pesticide to blooming, pollen-shedding or nectar-producing parts of plants if bees may forage on the plants during this time period. (Group 5)
  • spinosad (Blackhawk, Entrust, Success) at 0.047 to 0.094 lb ai/a. PHI 1 day. See individual product labels for forage and grain PHI. REI 4 hr. Do not exceed 0.45 lb ai/a per year (0.188 lb ai/a per year if used for livestock feed). Some formulations are OMRI-listed for organic use. For corn earworm at silking, applications may be made at 1- to 2-day intervals, if necessary, but do not make more than two consecutive applications of a Group 5 insecticide. These products are toxic to bees exposed to treatment for 3 hours following treatment. Do not apply this pesticide to blooming, pollen-shedding or nectar-producing parts of plants if bees may forage on the plants during this time period. (Group 5)
  • zeta-cypermethrin (Mustang, Mustang Max, Mustang Maxx) at 0.022 to 0.05 lb ai/a (Mustang). PHI 30 days for grain or stover; 60 days for forage. REI 12 hr. Do not exceed 0.2 lb ai/a per season (Mustang). Mustang, Mustang Max and Mustang Maxx are not for use on sweet corn seed. Zeta-cypermethrin is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. (Group 3A)

For additional information

http://insect.pnwhandbooks.org/vegetable/vegetable-pests/common/vegetabl...

http://horticulture.oregonstate.edu/content/corn-earworm