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Adopting a multi-pronged approach to managing alfalfa weevil larvae and other insect pests lets alfalfa maximize its early growth, minimize the stresses and produce greater tonnage and hay quality. A two-step program utilizing Mustang® Maxx insecticide or Steward® EC insecticide in alfalfa for control of weevils followed by a later application of Steward EC insecticide for extended residual control is a best practice for effective management of alfalfa weevil larvae damage in alfalfa. Including Dimethoate 400 EC insecticide as needed can also be beneficial when dealing with aphids.

When one of the following combinations of treatments are applied within the labeled timing and a third application is determined to be required prior to making the first cutting due to economical infestation of weevil larvae – such determination to be made solely by an FMC representative or an FMC authorized agent – FMC will cover up to either $6.00/A or $7.50/A for the third treatment.

Qualifying product Assurance Benefit

Alfalfa Weevil Larvae
Steward EC insecticide 5.3 fl. oz./A* followed by Steward EC insecticide 6 fl. oz./A*

Up to $6.00/A

Alfalfa Weevil Larvae
Mustang Maxx insecticide 4.0 fl. oz./A followed by Steward EC insecticide 8.0 – 11.3 fl. oz./A*

Up to $6.00/A

Alfalfa Weevil Larvae & Aphids
Mustang Maxx insecticide 4.0 fl. oz. + 1Dimethoate 400 EC insecticide 16 fl. oz./A followed by Steward EC insecticide 8.0 -11.3 fl. oz./A*

Up to $7.50/A

1 Must be FMC-branded Dimethoate 400 EC insecticide

*Steward EC insecticide’s federal label states 6.7 fl. oz. as the minimum rate for control of alfalfa weevils. The reduced rates in this program are pursuant to a 2EE recommendation R-4332 120519 12-04-19 for all registered states except TX and NY.  TX and NY are covered under a separate 2EE recommendation R-4333 120519 12-04-19.

Recommendations for Optimum Alfalfa Weevil Larvae Control:

  • Minimum of 6-8 inches of alfalfa growth is needed to optimize insecticide retention on foliage.
  • Treating alfalfa with less than 6 inches of growth can reduce effectiveness, residual and treatment performance.
  • Avoid treating two days before or after a cold weather event. Larvae will go deep into terminals or drop to the ground during cold and avoid feeding, thus reducing insecticide performance.
  • Use 3-5 GPA by air and 15-20 GPA for ground applications.
  • Include a surfactant (NIS, COC/MSO, or organo-silicone) to aid in coverage.

Program Requirements

  1. Must use and follow recommendations and labeled use rates listed in the chart above.
  2. Products must be applied according to label use directions.

Program Period:  January 1, 2022 – May 31, 2022
Program Geography: CO, ID, KS, MO, MT, NE, NV, NM, OK, OR, TX, UT, WA, WY
Program Submission Date: Contact your FMC representative within five days of identifying a problem.


  1. Assurance benefit is for product costs only. Application and other related costs are excluded from assurance payments.
  2. An authorized FMC representative must be notified of a claim within five days of identifying a problem. FMC must have a reasonable opportunity to inspect prior to any additional product applications. The authorized FMC representative must confirm inadequate product performance.
  3. Proof of purchase is required. Only FMC-branded products purchased from FMC authorized distributors or retailers and reported by Data Dimensions are eligible for payment under this program.
  4. Only product purchased for resale to growers is eligible for payment under the terms of this program.
  5. FMC reserves the right to audit all claims. Misreported sales of any type are a clear violation of this program and will be subject to audit and possible forfeiture of any and all program benefits.
  6. To qualify, growers must contact their FMC representative prior to the respray being needed.
  7. FMC is in no way liable or responsible for any grower failure to pay the retailer.
  8. FMC reserves the right to change any or all features of this program at any time.

Mustang Maxx insecticide is a Restricted Use Pesticide. Always read and follow all label directions, precautions and restrictions for use. Some products may not be registered for sale or use in all states. FMC, the FMC logo, Mustang and Steward are trademarks of FMC Corporation or an affiliate. ©2021 FMC Corporation. All rights reserved. Version 1, 2022-FFP-ASSURE-ALFALFA 09/21