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 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. If crop residue is to be fed to livestock, PHI is 30 days for grain & stover. Retreatment interval 3 days. Do not exceed 0.075 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)
  • 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. If crop residues are to be used for fodder, there is a 21 day PHI. REI 12 hr. Do not exceed 0.088 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. Extremely toxic to fish and aquatic invertebrates. (Group 3A)
  • bifenthrin (Bifenthrin 2EC, numerous products) at 0.033 to 0.1 lb ai/a. PHI 30 days. REI 12 hr. Do not exceed 0.3 lb ai/a per season. Bifenthrin is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply bifenthrin or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. Extremely toxic to fish and aquatic invertebrates. (Group 3A)
  • bifenthrin/zeta-cypermethrin (Hero) at 0.04 to 0.1 lb ai/a. PHI 3 days. Do not graze livestock in treated areas or cut treated crops for feed within 3 days of the last application. REI 12 hr. Do not exceed 0.4 lb ai/a per season. Refer to product labels for application limits if multiple products containing zeta-cypermethrin are to be used in the same 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)
  • chlorpyrifos (numerous 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. Chlorpyrifos is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply chlorpyrifos or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 1B)
  • chlorpyrifos/gamma cyhalothrin (Cobalt) at 0.13 to 0.26 lb ai/a. Do not apply within 21 days before harvest of grain, ears, forage or fodder. 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)
  • 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. Esfenvalerate 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. Esfenvalerate is highly toxic to fish and aquatic invertebrates. (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 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 21 days. If crop residues are to be used for livestock, PHI is 1 day for grazing, 21 days for fodder or silage. REI 24 hr. Apply no more than 0.12 lb ai/a per season. Refer to product labels for application limits if products containing gamma-cyhalothrin and products containing lambda-cyhalothrin are to be used in the same season. Highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply lambda-cyhalothrin or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. Lambda-cyhalothrin is extremely toxic to fish and aquatic organisms and toxic to wildlife. (Group 3A)
  • methomyl (Lannate LV; other products) at 0.225 to 0.45 lb ai/a. PHI 21 days for ears or stover. REI 48 hr. Do not exceed 2.25 lb ai/a per season. (Group 1A)
  • 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, other products) 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 Maxx) at 0.022 to 0.05 lb ai/a (Mustang) or 0.011to 0.025 lb ai/a (Mustang Maxx).. Do not apply within 7 Days of harvest of crop residues for stover or forage. REI 12 hr. Do not exceed 0.2 lb ai/a per season (Mustang) or 0.1 lb ai/a (Mustang Maxx). Mustang 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