University of Arizona a dot Cooperative Extension

Cross-Commodity Guidelines for Managing Whiteflies and Sustaining Chemical Efficacy in Arizona

5th Annual Melon Field Day - Maricopa Agricultural Center - June 2, 1999 (rev. 7/01)

Arizona Cross Commodity Working Group, Technical Committee: Mike Arbogast, Tim Dennehy, Peter Ellsworth, Lin Evans, Todd Hannan, Ed Minch, Bob Nichols, John Palumbo, & Kai Umeda

Mike Arbogast, Tim Dennehy, Peter Ellsworth, Lin Evans, Todd Hannan, Ed Minch, Bob Nichols, John Palumbo, and Kai Umeda. 1999 (Rev. 7/2001). Cross-Commodity Guidelines for Managing Whiteflies and Sustaining Chemical Efficacy in Arizona . University of Arizona, College of Agriculture and Life Sciences, Cooperative Extension, Tucson, Arizona. URL:

A more complete discussion of this topic can be found in:
Palumbo, J.C., P.C. Ellsworth, T.J. Dennehy & K. Umeda. (1999) Cross commodity management of whiteflies and chemical efficacy in Arizona. In D. N. Byrne [ed.], 1999 Vegetable Report. Series P-117, AZ 1143 , University of Arizona, College of Agriculture, Tucson, AZ. pp.108-120.


During the past decade, the silverleaf whitefly in Arizona has been relegated to a managed pest. This was achieved through the development of management programs in cotton, melons and vegetables which utilized cultural practices, selective insecticides, sampling and monitoring plans, and optimally-timed insecticide use. Growers in all commodities have been quick to adopt and modify these management strategies as new insecticide compounds are made available.

Admire® (Section 18) in melons and vegetables, and Danitol® in cotton, were first available to Arizona growers in 1993. However, due to excessive use, pyrethroid efficacy was significantly reduced in some growing areas by 1995. In response, the Arizona Cotton Growers Association (ACGA) requested limited use of and received an emergency exemption for two insect growth regulators, Knack® and Applaud®. Availability of the IGRs made possible the UA Integrated Resistance Management program that promoted non-chemical management of whiteflies, in conjunction with a three-stage chemical use strategy designed to maximize the longevity of insecticide modes of action. Implementation of this program has since reduced insecticide use for whitefly management overall and provided for recovery of pyrethroid efficacy.

Admire continues to provide consistent whitefly control on melons and leafy vegetables. However, the lack of registered foliar insecticides available in melons prompted the Western Growers Association (WGA) in 1998 to request an emergency exemption for Applaud on melons. A Section 18 label (expires 7/14/01; Section 3 pending) is now available on melons to control whitefly and help sustain Admire efficacy. Because whitefly exposure to Applaud may overlap between melons, cotton and fall vegetable crops, cooperation will be needed among growers to harmonize insecticide use across commodities, to cover management needs of the respective groups, and to protect long-term Applaud efficacy. In addition, preserving Admire efficacy is critical for managing whiteflies and sustaining alternative chemistries in vegetables and melons.

In the spring of 1998, the leadership within the WGA and ACGA met to discuss the possibilities of developing a cross-commodity approach for managing whiteflies and sustaining long term insecticide efficacy. A Cross-Commodity Working Group was formed, and discussions focused on formulating practical pest management guidelines for cotton, melon and vegetable growers in Arizona. Participants also included representatives from the Arizona Vegetable Growers Association, Yuma Vegetable Shippers Association, Arizona Cotton Research and Protection Council, Cotton Incorporated, and Arizona Department of Agriculture. A technical committee was formed and comprised of University of Arizona scientists and extension specialists, Arizona Department of Agriculture officials and pest control advisors from each commodity and regional growing area. This group was initially charged with developing insecticide use guidelines for the 1999-2000 growing seasons.

The efforts of the technical committee have resulted in general guidelines for managing whiteflies and specific recommendations for Applaud and Admire use. We achieved this by compiling data for crop production, insecticide use, and simulated whitefly population dynamics for key host crops within three distinct growing regions in Arizona. Graphs were constructed that when overlaid identified important, multidimensional interactions within cropping systems. Recommendations are focused on restricting Applaud use to only once per crop season in use windows, with additional guidelines for reducing the possibility of exposing successive whitefly generations to the same mode of action. The diversification and limitation of Admire and other active ingredients, and the employment of cultural practices should also be considered.


Ideally, these strategies were formulated to optimize whitefly management and maximize the efficacy and longevity of insecticide chemistries used for whitefly control across commodities. We recognize, that under certain conditions these practices may be difficult to implement, but emphasize they may be necessary for sustainability of chemical efficacy in Arizona cropping systems.

General Guidelines
Avoid Problems Through Cultural Management
  • Crop sanitation, crop sequence, crop placement
  • Agronomic considerations
  • Prompt removal of post-harvest residue
Scouting, Sampling and Detection
Ensure Effective Chemical Use
  • No more than 2 uses per active ingredient per season
  • No more than 2 uses of pyrethroids per season
  • Consider applying insecticides by directed ground sprays to optimize spray deposition whenever possible
  • Treat whole fields when applying IGRs
  • Use only recommended products and rates (PDF file, 109KB) necessary to accomplish desired control
  • Do not apply insecticides below labeled rates


Specific Guidelines for Applaud® and Admire®

The guiding principles behind these recommendations are to maximize utility, efficacy and longevity of these valuable active ingredients for all commodities, and minimize the risk of resistance. The objectives of our guidelines are to optimize frequency of use ( e.g., number of applications / season or year), to avoid sequential exposure of multiple generations of whiteflies across commodities, and to encourage cooperation and communication among all growers within regional cropping systems

Applaud Use Recommendations

  • Limit Applaud use to 1 application per crop season (one use in spring melons, cotton, and fall melons).
  • Restrict Applaud use to no more than 3 applications per year in a multi-crop community.
  • Do not expose multiple, sequential generations of whitefly to Applaud.
  • Coordinate treatments of adjacent fields such that, when thresholds indicate the need for Applaud applications:
    • they are made within 1 week (within the same whitefly generation), OR
    • the interval between Applaud sprays is more than 4 weeks, or at least 2 whitefly generations.
  • If a field requires treatment for whiteflies and an adjacent field has been treated with Applaud within 28 days (see previous statement), use an alternative chemistry with a different mode of action.
  • Assuming Admire is used on lettuce, use alternatives to Applaud (pending registration) for controlling whiteflies in lettuce.

Admire Use Recommendations

  • Do not use a foliar formulation of imidacloprid (Provado®) in cotton, except for specific chronic aphid problems.
  • Do not apply Provado (or other foliar neonicotinoids) on crops that have been planted or side dressed with Admire.
  • Consider foliar alternatives (pyrethroids, endosulfan, Applaud) to Admire use for whitefly control in the following conditions:
    • Fall lettuce and cole crops planted after temperatures have declined and there is no significant source (i.e. alfalfa, cotton or melons) of whiteflies within a one mile radius
    • Fall lettuce and cole crops that are planted after whitefly movement subsides and are harvested before aphid populations typically become abundant (eg., Oct 10 ~ Nov 10 planting dates in Yuma).
    • Early-spring planted melons which traditionally harvest before the emergence of F2-F3 generations.
  • Consider an alternative foliar spray program (MSR®, Provado, endosulfan, Orthene®) rather than a preventative Admire treatment for aphid control on spring lettuce and cole crops where applicable.


Full Disclaimers

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director Cooperative Extension, College of Agriculture and Life Sciences, The University of Arizona.

The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

Any products, services, or organizations that are mentioned, shown, or indirectly implied in this web document do not imply endorsement by The University of Arizona.

Questions about this document can be directed to:
John C. Palumbo, Research Scientist (Entomology)
Peter C. Ellsworth, Specialist, IPM/Entomology
Timothy J. Dennehy, Professor Entomology
Kai Umeda, Area Extension Agent, Vegetable Crops

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