Field and silage corn-Aphid


Bird-cherry oat aphid (Rhopalosiphum padi)
Corn leaf aphid (Rhopalosiphum maidis)

Pest description and crop damage Orange green to olive green and black aphids suck sap. They may become very abundant, especially later in the season. Heavy populations may be evident if golden yellow streaking is found on the leaves. Large populations of aphids may reduce kernel number and size.

Management-chemical control

  • abamectin/thiamethoxam (Avicta Duo 250 Corn) Group 4A 6 nematicide/insecticide-Apply as slurry to corn seed. Only to be treated in Syngenta-certified facilities, Farmer application not permitted.
  • alpha-cypermethrin (Fastac CS) Group 3A insecticide at 0.018 to 0.025 lb ai/A (2.7 to 3.8 fl oz). REI 12 hr. PHI 30 days grain and stover; 60 days forage. Retreatment interval 3 days. Do not exceed 0.075 lb ai/A per season.
  • azadirachtin (Aza-Direct) Biological insecticide at 16 to 32 oz formulated product/A. PHI 0 days. REI 4 hr. Some formulations are OMRI-listed for organic use.
  • Beauveria bassiana (Mycotrol ES, Mycotrol ESO, BotaniGard, several variations of each) mycoinsecticide at 4 oz/A. REI 4 hr. PHI 0 day. OMRI-listed for organic use.
  • bifenthrin (Brigade 2EC) Group 3A Insecticide at 0.033 to 0.1 lb ai/A. PHI 30 days for harvest, grazing, or cutting for feed. REI 12 hr. Do not apply more than 0.3 lb ai/A per season.
  • bifenthrin/zeta-cypermethrin (Hero EW) Group 3A Insecticide at 0.04 to 0.1 lb ai/A. PHI 30 days grain and stover; 60 days forage. REI 12 hr. Do not graze for 30 days after treatment. Do not exceed 0.15 lb ai/A per of zeta-cypermethrin per crop.
  • chlorantraniliprole/lambda-cyhalothrin (Besiege) Group 3 & 28 insecticide at 5 to 10 fl oz ai/A (suppression only). PHI 21 days. REI 24 hr. Do not exceed 0.12 lb ai of lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole per acre per growing season. Retreatment interval 7 days.
  • Chromobacterium subtsugae (Grandevo) bioinsecticide at 0.6 to 0.9 lb ai/A per 100 gal. PHI 0 days (2 to 3 lb/A). REI 4 hr. OMRI-listed for organic use.
  • dimethoate (Dimethoate 400 EC) Group 1B insecticide/miticide at 0.33 to 0.5 lb ai/A (0.6 to 1.0 pint/A). PHI 14 days forage; 28 days grain. REI 48 hr. Do not exceed 0.5 lb ai/A per season. Do not apply during pollen shed if bees are foraging actively.
  • esfenvalerate (Asana XL) Group 3 insecticide at 0.03 to 0.05 lb ai/A (5.8 to 9.6 fl oz/ac). For optimum results, direct the spray at the aphid population so as to achieve maximum coverage of the exposed insects. Aphids not contacted by the spray, such as in whorls and leaf axils, may not be adequately controlled. PHI 21 days. REI 12 hr. Do not exceed 0.25 lb ai/A per season.
  • flupyradifurone (Sivanto 200SL) Group 4D insecticide at 0.09 to 0.14 lb ai/A (7.0 to 14.0 fl oz/A). PHI 7 days forage; 21 days grain, stover or straw. REI 4 hr. Retreatment interval 7 days. Do not exceed 0.365 lb ai/A per calendar year.
  • malathion (Fyfanon 8 LB, Gowan Malathion 8) Group 1 insecticide at 0.6 to 1 lb ai/A (1 pint/A). PHI 7 days. REI 12 hr. Limit 2 treatments per year. Retreatment interval 7 days.
  • methomyl (Lannate SP) Group 1A insecticide at 0.23 to 0.45 lb ai/A. PHI 21 days for ears, 3 days for forage, or 21 days for fodder. REI 2 days. Initial application when corn is at 1-2 leaf stage for early control with second application 5-7 days later if needed. Do not exceed 2.25 lb ai/A or 5 treatments per season. Retreatment interval 5 to 7 days.
  • sulfoxaflor (Transform WG) Group 4C insecticide at 0.023 to 0.047 lb ai/A. PHI 14 days for grain or straw. Do not apply more than 0.09 lb ai of sulfoxaflor per acre per year.
  • tebuconazole/lambda-cyhalothrin (Crossover) Group 3 fungicide/insecticide at 0.14 to 0.16 lb ai/A (8 to 9.5 oz/A). PHI 21 days fodder and silage. REI 24 hr. Retreatment interval 7 days. Do not exceed 0.48 lb ai/A tebuconazole or 0.12 lb ai/A lambda-cyhalothrin per season.
  • zeta-cypermethrin (Mustang) Group 3A insecticide at 0.034 to 0.05 lb ai/A. PHI 7 days for grain, stover and forage. REI 12 hr. Do not exceed 0.2 lb ai/A per season. Retreatment interval 3 days.