Chemical Control of Corn Pests

Chemical Control of Corn Insects

Armyworms

Threshold: Whorled-sized plants—most plants show damage, 3 larvae/plant

Insecticide Pounds Active Ingredient/A Amount of Formulated Product
§ Lambda-cyhalotrin (*Warrior II) 0.02-0.03 (See label) 1.28—1.92 fl. oz./acre
chlorpyrifos (*Lorsban 4E) 0.5—1.0 1—2 pt./A
Min. days to harvest-21. Foliar application. Consult the label.
§ Permethrin (*Pounce, *Ambush) 0.1—0.2 see label
Apply before brown silk formation. Consult the label.

Cutworms

Threshold: 5% or more of plants cut. See text.

Insecticide Pounds Active Ingredient/A Amount of Formulated Product
chlorpyrifos (*Lorsban 4E) 0.5—1.0 1—2 pt./A
Min. days to harvest-21. Foliar application. Consult the label.
§ Permethrin (*Pounce, *Ambush) 0.1—0.2 see label
Apply before brown silk stage. Consult the label.
§ Lambda-cyhalotrin (*Warrior II) 0.015—0.025 0.96—1.6 fl. oz./acre

Corn rootworms (Larval control)

Threshold: May be a problem in second-year or later corn. Average of 2NCR or WCR beetles/plant at silking previous year. CRW insecticides not generally recommended for first-year corn. See text.

Insecticide Pounds Active Ingredient/A Amount of Formulated Product
§Clothianidin (Poncho)   1.25 mg/kernel
Material is applied to the seed by the seed supplier. Consult the label.
§ Tefluthrin (*Force 3G)   4 oz./1,000 lin. ft.
Toxic. Apply in a 7-in. band in front of the press wheel (T-Band) or at planting. Highly toxic to fish. Consult the label. Small leaching potential 1. Large runoff potential 1.
§ Thiamethoxam (Cruiser)   1.25 mg/kernel
Material is applied to the seed by the seed supplier. Consult the label.
BT-CRW Modified Corn Varieties
Genes for various CRW active BT toxins have been incorporated into corn varieties adapted to NY. Currently, those technologies are known as YieldGard-Rootworm, YieldGard VT and Herculex-Rootworm. All of the current technologies have been shown to be effective under NY conditions. Use of these technologies is the most appropriate under situations of heavy rootworm larval pressure, commonly occurring in third year or longer continuous corn production. Each of these technologies requires the planting of a BT-CRW free refuge equaling 20% of the BT acreage. Detailed requirements about the refuge should be obtained from the seed supplier.

Corn rootworms (Adult control)

Threshold: Treatments not recommended unless there is an average of 10 beetles/plant at silking, 50% of corn silks are brown, silks <0.5 in. See text.

Insecticide Pounds Active Ingredient/A Amount of Formulated Product
§ Lambda-cyhalotrin (*Warrior II) 0.03 lb./A (See label) 1.92 fl. oz./A
§Chlorpyrifos (*Lorsban 4E) 0.5—1.0 1—2 pt./A
Min. days to harvest-21. Foliar application. Consult the label.
§ Permethrin (*Pounce, *Ambush) 0.1—0.2 see label
Apply before brown silk stage. Consult the label.

Wireworms and white grubs

Threshold: None available.

Insecticide Pounds Active Ingredient/A Amount of Formulated Product
Terbufos (*Counter)   6 oz./1,000 lin. ft.
Highly toxic. Apply in a 7-in. band in front of the press wheel (T-Band) or in-furrow at planting. Consult the label. Small leaching potential 1. Medium runoff potential 1.
Formulations: F=flowable, D=Dust, PB=planter box, G=granular
*Restricted-use pesticide; may be purchased and used only by certified applicators or used by someone under the direct supervision of a certified applicator.
1USDA and NRCS guidelines.
§ Active ingredient meets EPA criteria for acute toxicity to bees.