Dennehy and resistance lab recognized

Tim Dennehy, University of Arizona Extension entomologist, has been honored as the university's Distinguished Outreach Professor.

The award went to Dennehy for his work in establishing the UA Extension Arthropod Resistance Management Lab, the first facility of its kind. Dennehy received the award at UA's winter commencement.

The facility has provided the infrastructure for outreach and research that has helped to solve a crisis with whiteflies in Arizona and has been instrumental in maintaining the efficacy of genetically modified cotton against pink bollworm.

Dennehy has garnered millions of dollars to support his outreach programs from sources as diverse as the U.S. Department of Agriculture, U.S. Environmental Protection Agency, and industry and commodity groups, including Arizona Cotton Growers Association.

“He was instrumental in identifying pesticide problems affecting the whitefly and directed us to other strategies, which saved the Arizona cotton industry in the early 1990s,” said Rick Lavis, executive vice president of the Arizona Cotton Growers Association.

“He can justifiably claim a major role in reducing the number of annual insecticide applications in Arizona cotton from over five when he came to less than two at present,” said Robert Nichols, director of agricultural research, Cotton Incorporated.

“Tim is the best thing that has ever happened to our working relationship with The University of Arizona,” said Robert T. Staten, center director, U.S. Department of Agriculture, Phoenix.

“The levels of co-ordination and cooperation achieved by Tim and his colleagues in Arizona represent one of the most exciting accomplishments with cotton pest management in any part of the world,” said Ian Denholm, head of the Plant and Invertebrate Ecology Division, Integrated Approach to Crop Research, Rothamsted, England.

This award, said Dennehy, “is extremely significant to the promoting of excellence in Extension and the contributions of many in unparalleled teamwork.”


This new title, established in 2004, recognizes distinguished outreach accomplishments in the same way that the University of Arizona has long recognized distinguished teaching and distinguished research. It represents the university making commitment to what Dennehy calls “cutting-edge Extension.”

Cutting-edge Extension is done by “standing on the shoulders of exceptional researchers.

“The accomplishments in management of insect resistance in Arizona cited when the university conferred me this award resulted from unique synergism of our multi-agency team and contributions of many.”

Contributing program leaders cited by Dennehy are: Professors Bruce Tabashnik, Yves Carrière, Peter Ellsworth, and John Palumbo of the University of Arizona. He also cited his work with Larry Antilla of the Arizona Cotton Research and Protection, Lavis, Nichols, Staten and Tom Henneberry of the USDA.

Dennehy said his role as founding director of the Extension Arthropod Resistance Management Laboratory has been to “provide a bridge between the University-and USDA-based programs and cotton producers throughout Arizona. Many times this has involved implementation of ideas, methodology and information provided by other members of our team, and funding and technical support provided by Arizona cotton growers.”

Insect resistance is the Achilles' heel of modern insect management, said Dennehy. Integrated pest management (IPM) has been the paradigm of insect management since the 1970s.

“IPM dictates that all practical non-chemical control measures be employed before resorting to use of insecticides. Insecticide use is justified when monitoring or other predictive tools indicate that pest densities have exceeded economic thresholds. This approach has made it all the more critical that insecticide treatments, once resorted to, work as expected, because financial losses are virtually a certainty otherwise,” Dennehy noted.

Owing to high temperatures and year-round conditions permitting insect development, pesticides are required to some degree in most fruit, vegetable, and fiber crops of the low deserts of the Southwest. “Older highly toxic pesticides have been replaced with products that are functionally the equivalent of insect birth control. These modern tools of IPM have reduced negative impact on beneficial organisms, humans, and the environment, but are very effective at controlling target pests,” Dennehy said.

The problem is, he added, is that there are relatively few of these modern IPM-compatible insecticides available. Those that exist must be used as sparingly as possible and every effort must be made to delay their loss to resistance.

e-mail: [email protected]

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