Ag Line: Stink Bug Control in Corn
By Wade Parker County Extension Coordinator

Stink bugs are back. After low levels the last two years, spring rains have increased bug populations, especially brown stink bugs. Corn is most susceptible to stink bug injury during ear formation before tasseling. Bugs will feed through the sheath, causing a dead spot on the ear. As the ear expands, it becomes distorted and curves usually outward. Feeding during silking and pollen shed also will kill kernels on the ear. Once the ear has elongated, stink bug feeding during the blister and milk stages blast individual kernels usually causing them to abort.

Recent case studies at Tifton have found no significant affect on corn grain production at infestation of 1 brown stink bug per plant. The old threshold (5% infested plants) is too low. I suggest using a 25% infested plants (1 bug per 4 plants) as a threshold during ear elongation to pollen shed and 50% infested plants (1 bug per 2 plants) during the later part of pollen shed and blister/milk stage. Bug is defined as adults and/or large nymphs. Initially stink bugs tend to be more prevalent on the field edge, so only a perimeter spray may be needed.

Methyl parathion (Declare 4EC, Methyl parathion 4E, Penncap-M FM) and Warrior 1SC and Capture 2E are effective in controlling stink bugs in corn. Parathion is the best choice for brown stink bugs. The label rate for the 4 lb/gal formulation is ½ pint per acre. For Penncap-M (2 lb/gal), use 1 pint/acre. However, the parathion label does not allow for application during pollen shed. If early pollen shed is just beginning, apply parathion in the evening to avoid bees. At full pollen shed use, Capture / Brigade or Warrior / Karate Z or similar products can be used and will give suppression of brown stink bugs. Capture at 3.2-3.8 floz. per acre and Warrior at 3.2-3.84 floz. per acre, Karate Z at 1.60 to 1.92 floz./ acre are better choices than parathion for southern green stink bug. Parathion has less than 12 hours activity; therefore, re-infestation can occur after treatment. The pyrethroid treatments have residual activity for 1-2 weeks. Bidrin and Vydate are used for stink bug control in cotton and are not labeled for use on corn.

Karate Z now has corn on the label.

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