General Information


Insect control may be reduced at low spray volumes under high temperature and wind conditions.

Some reduction in insect control may occur under unusually cool conditions.

Flood irrigation: To avoid contamination of irrigation tail waters, do not flood irrigate within 24 hours following a soil surface or foliar application of Warhawk.

Insecticide Resistance Management (IRM)

Warhawk contains a Group 1B insecticide. Insect/mite biotypes with acquired resistance to Group 1B may eventually dominate the insect/mite population if Group 1B insecticides are used repeatedly in the same field or in successive years as the primary method of control for targeted species. This may result in partial or total loss of control of those species by Warhawk or other Group 1B insecticides.

To delay development of insecticide resistance, the following practices are recommended:

- Avoid consecutive use of insecticides with the same mode of action (same insecticide group) on the same insect species.

- Use tank mixtures or premix products containing insecticides with different modes of action (different insecticide groups) provided the products are registered for the intended use.

- Base insecticide use on comprehensive Integrated Pest Management (IPM) programs.

- Monitor treated insect populations in the field for loss of effectiveness.

- Contact your local extension specialist, certified crop advisor, and/or manufacturer for insecticide resistance management and/or IPM recommendations for the specific site and resistant pest problems.


Broadcast Foliar Application

Apply with conventional power-operated spray equipment using nozzles and spray pressures specified for insecticides. Apply Warhawk in a spray volume of not less than 2 gallons per acre for aerial application equipment (fixed wing or helicopter) or not less than 10 gallons per acre for ground equipment, unless otherwise specified. Increase spray volume to ensure adequate coverage with increased density and height of crop canopy. See Spray Drift Precautions section for specifications on droplet size.

Ground Application: Orient the boom and nozzles so that uniform coverage is obtained. The swath width should not be wider than the boom. Follow nozzle manufacturer's recommendations for insecticide nozzles with respect to nozzle type, pressure, and spacing.

Broadcast Soil Application

Apply with conventional power-operated spray equipment that will apply the product uniformly to the soil surface. Use nozzles that produce medium or coarse droplets (235-400 microns). Unless otherwise indicated, a spray volume of 10 gallons or more per acre is recommended. For band application, use proportionally less spray volume.

Aerial Application

Use a minimum spray volume of 2 gallons per acre and follow recommendations for best management practices for aerial application, above.

Marking of swaths by flagging, permanent markers or use of GPS equipment is recommended.

Limitations, Restrictions, and Exceptions


(For use only in Arizona, California, Idaho, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, Oregon, South Dakota, Washington and Wisconsin)

- Apply as a ground broadcast foliar spray. Use sufficient volume of finished spray to ensure thorough coverage of crop foliage. Note: Warhawk may be applied aerially or with ground equipment for control of armyworms and grasshoppers.

Pest-Specific Use Directions:

1. For armyworms, asparagus beetles, asparagus aphids, and grasshoppers, apply during the fern stage when field counts or crop injury indicates that damaging pest populations are developing or present.

2. For cutworms, it is preferable to apply when the soil is moist and worms are active on or near the soil surface.

3. For symphylans, apply at least two weeks before harvest for optimum control.

Specific Use Restrictions:

- Do not make more than 1 preharvest application per season or apply within 1 day of harvest.

- Do not make more than 2 postharvest applications during the fern stage.

- Do not make a second application of Warhawk or other product containing chlorpyrifos within 10 days of the first application.

- Maximum single application rate preharvest or postharvest is 1 lb ai chlorpyrifos per acre.

Restricted Entry Interval

24 hours

Exception: If the product is soil-injected or soil-incorporated, the Worker Protection Standard, under certain circumstances, allows workers to enter the treated area if there will be no contact with anything that has been treated.