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Most successful biological pest exclusion program ever

Wally Shropshire of Blythe, Calif., and famed movie director Cecil B. DeMille of Hollywood share a lot more in common than just calling California home. They both are epic creators — gathering together casts of thousands to attract millions: Wally even more so than the late Cecil.

Shropshire has been orchestrating — with a supporting production ensemble of hundreds — a cast of trillions that saved millions from a horde of lurking evildoers. Wally's legacy over the past 38 years would make Hollywood proud. However, Wally's work will never get him invited to Oscar night, but there are thousands of cotton growers who would be more than willing to dole out statues by the truckloads for the accomplishments of the band Wally leads.

Former California Department of Food and Agriculture director Jack Parnell called the epic Wally has directed since 1974 “The Greatest Story Never Told.”

Western Farm Press and the Cotton Foundation are telling the story this year with its Far West High Cotton Award for 2006. Rather than honor a farm family for producing cotton with a commitment to environmental stewardship, this year's Far West High Cotton award goes down a different path. The honor goes to the California Cotton Pest Control Board, or as it is better known, “The California Pink Bollworm Program” and its chairman Shropshire accepted the High Cotton Award at this year's Beltwide Cotton Conferences in San Antonio, Texas.

Why? The answer is simple. It is undoubtedly the world's most successful and longest running area-wide integrated biological pest control program, and the program with a current budget of $5.5 million has been funded virtually with 100 percent grower funds almost from its inception nearly four decades ago.

It is a program that has negated the use of millions of pounds of pesticides. The California San Joaquin Valley pink bollworm exclusion program is an environmental benchmark for the ages.

There have been at least 38 million acres of some of the highest quality cotton produced in the world in California's San Joaquin Valley since growers banded together and opened their checkbooks to keep the pink bollworm — the world's most destructive cotton pest — out of the San Joaquin. Using a conservative 2.5-bale average, this acreage represents roughly 100 million bales of cotton.

And Wally's entourage has succeeded longer than anyone imagined in the beginning, using an integrated pest control approach, relying on trapping, sterile release, crop residue destruction, and pheromone confusion technology to keep PBW infestations below economic impact levels for decades.

Since 1968, at last 20 trillion irradiated, sterile pink bollworm moths have been aerially distributed over the San Joaquin for 38 years to keep PBW at bay.

“Bottom line is that the California cotton industry would not be here today without the pink bollworm program,” said Earl Williams, president of the California Cotton Ginners and Growers Association. Williams has logged 40 years in the California cotton industry and added, “We would have run out of options a long time ago and likely would be where the Imperial Valley and other desert cotton growing areas are today had growers not formed the cotton pest control board and funded out of their own pockets the pink bollworm program.”

In 1977 there were 140,000 acres of cotton and 12 cotton gins in Imperial Valley. Today there is one gin and less than 12,000 acres, and the pink bollworm is largely responsible for that.

At the height of the pink bollworm infestation, desert cotton producers were spending annually an average of $125 per acre in Palo Verde Valley and $175 per acre in Imperial Valley trying to control pink bollworm. It was not uncommon at the height of the pink bollworm problems for a grower to spend $300 per acre on pesticide sprays.

Not one SJV cotton producer has spent a single dime to apply a pesticide to control PBW. It costs SJV producers about $2 per bale or about $5 per acre annually for that rare privilege. At four or five bales, it is still a bargain at $8 to $10 per acre.

PBW became a major problem for Arizona and southern California cotton producers in the mid-1960s. Jack Stone, Stratford, Calif., cotton producer, like Shropshire, is one of the two original board members still serving, recalled a group of SJV producers going to Arizona and southern California to see firsthand what type of threat they were facing.

Less than 300 miles separate Blythe, Calif., where the PBW was wreaking havoc at that time, and Bakersfield, Calif., where there were no pink bollworms. Growers and researchers were convinced it would only be a matter of time before PBW would reach the San Joaquin Valley without an area-wide exclusion effort, recalled Stone.

“We realized early on that it would jeopardize our livelihoods, and we decided to form the cotton pest control board to develop a plan to address the problem,” said Stone. The producers went to the legislature to get the authority to levy an assessment to support the use of sterile insects to overwhelm native populations.

Surprisingly, it was not a novel idea 40 years ago. It had been used since 1953 to control screwworm, an insect that feeds only on the living tissue of warm-blooded animals. It was a major problem for American livestock.

USDA entomologists used the technique first to eradicate screwworm in the Southeast and then the program was expanded to eventually eradicate the screwworm from the entire United States, Mexico and most of Central America.

Screwworm eradication from the U.S. began in 1962 under the direction of ARS labs in Kerrville and in Mission, Texas. Shropshire said it was from the work at Mission that the California sterile release pink bollworm program had its beginning.

“The amazing thing to me back then and still today is how very few cotton growers objected to the bale assessment we used to start and maintain the program,” said Stone. “Growers have always willingly paid it and it has been a tremendously successful program over the years. It has exceeded my expectations by far.

“I am almost certain that the pink bollworm program is why we are still growing cotton in the San Joaquin Valley today,” said Stone.

Bill Tracy, partner in the family-owned Buttonwillow Land and Cattle Co. in Kern County, was introduced to the idea of releasing sterile moths to control native pests when he returned to the farm after Army Reserve active duty in the late 1960s.

Informational meetings were being conducted in the valley at that time and “you can imagine the initial reaction of pre-bio engineering farmers when state bureaucrats (from the California Department of Food and Agriculture) were suggesting releasing the most devastating cotton critter in the world over the San Joaquin Valley.” It took some convincing that there would be no non-sterile moths inadvertently released as part of the sterile drops.

Fortunately, said Tracy, Shropshire was at those early meetings telling SJV growers, “Gentlemen, the Palo Verde Valley is already infested, and I'd give a million dollars to be in your shoes with the opportunity to prevent the pink bollworm from getting into your valley.”

In 1967 the state of California paid to spray every acre of cotton in the Palo Verde Valley 13 times with Sevin to prevent the pink bollworm from getting into the desert valley, recalled Shropshire. And the state even mandated that cotton trailers crossing into California from Arizona across the Colorado River had to be fumigated before going to the gins on the California side. Attempts to keep pink bollworm on the Arizona side of the river failed and desert cotton growers have had to live with the pinkie ever since.

“We were naive to think the pinkie would not cross the Colorado,” he said.

“There was no question in my mind had we not had the sterile program all these years, we would have a hellacious pinkie problem in the San Joaquin today,” said Shropshire.

Jeff Hildebrand of Bakersfield, Calif., recently went off the cotton pest control board after having served since 1984. His family has farmed in California since 1937.

“The pink bollworm program is one of the least known, most environmentally sound pest control programs in the country. It has saved California growers millions of dollars while costing them next to nothing. Just the environmental significance of the amount of pesticides it has saved growers is staggering,” said Hildebrand.

One of the key people in the success of the program has been USDA entomologist Bob Staten, who has been involved with the program since 1970. He has been an adviser to the board and has conducted numerous PBW research projects in the San Joaquin and in the desert valleys.

“The success of this program is huge, even if you just look at what hasn't happened in the SJV. In the history of the program, there has only been one incidence of a measurable infestation in the SJV. No grower in the SJV has ever had to apply pesticides for pink bollworm control,” said Staten.

CDFA has managed the program since its inception. Bob Roberson was branch chief of the CDFA Integrated Pest Control branch and worked with the program from 1977 until he retired in 2000.

“It was amazing how visionary the board was in seeing the importance of keeping pink bollworm out of the valley — how growers and ginners like Wally and Jack and others had the vision to see what was needed,” said Roberson.

“And these men followed the direction of an outstanding group of scientists like Bob Staten, Fred Stewart and Tom Miller. James Brazil was another entomologist who was a key part of the program, especially when the board got involved in eradicating the boll weevil in Arizona and from southern California,” said Roberson.

Working with the cotton pest control board and these scientists “was the highlight of my career,” said the retired CDFA administrator.

Jim Rudig is program supervisor for the program. He began his CDFA career as a temporary employee working on the new technology of releasing sterile PBW moths to overwhelm any native populations in 1967. When a sterile moth mates with a native, there is no offspring and it breaks the generation cycle.

“Everything we did in the beginning was new technology and it was not very sophisticated,” said Rudig. One of the challenges initially was to find how to effectively release the sterile PBW moths.

“In the screwworm program, they irradiated and released larvae. They found you could not do that with pink bollworm. We had to release the moths,” recalled Rudig.

The first releases were done by hand with moths inserted into toilet paper tubes stuffed with excelsior — “bunny grass. Yea, the stuff you find in Easter baskets. I remember going to the drug store in Bakersfield and buying all the bunny grass in the store to stuff in toilet paper tubes. We would walk the cotton fields putting out the moths in those paper tubes,” said Rudig.

That quickly gave way to the successful development of aerial release equipment to blanket the valley weekly with sterile PBW moths during the growing season.

“In the beginning it amazed me how careful the members of the cotton pest control board were to protect the cotton industry. In the 1960s, most of the leaders were young men, yet they have always exhibited a vision into the future for their industry,” said Rudig.

Rudig brings a unique perspective to the program because interspersed with his work on the PBW program have been stints eradicating Medfly infestations from urban areas.

“It has been extremely gratifying to work on the pink bollworm program because of my experience in using pesticides to eradicate Medfly,” he said.

“I am not against the use of pesticides. They are important to control insect pests if done properly, but when you can do what cotton growers have done working with CDFA for almost 40 years, it is truly amazing,” said Rudig, who was a leader in moving the PBW technology to the fight against Medfly.

Rudig said it is almost impossible to keep Medfly out of California's urban areas like southern California, and CDFA now aerially drops sterile Medfly over the Los Angeles area to minimize infestations.

Using sterile insect releases to keep a pest at bay is a numbers game, but those numbers can be deceiving, pointed out Rudig. Trapping to capture both sterile and native PBW is an integral part of the program.

“In 2005 we released 231 million steriles and captured 231,000 in traps. Because we are trapping only males, that represents only 0.2 percent. We trapped only 116 natives at the same time,” said Rudig. However, if you use the same trap percentage as sterile moths, “it is easy to recognize that a native population can quickly get away from you without a sterile release program. Just because you caught one native moth does not mean it is the only one out there.”

Early in the program there were doubts expressed that the pink bollworm could overwinter in the San Joaquin Valley. Staten researched the issue with caged cotton plots in the middle of a Kern County cotton field one season. He recorded five generations in those cages; end of debate about overwintering.

Williams has high praise for the board and the CDFA crew that runs the program. In recent years the board has approved funding for CDFA trapping for silverleaf whitefly, a potentially devastating pest that can cause severe damage to cotton lint and the valley's high quality cotton reputation.

The California growers and ginners groups have conducted an aggressive campaign to prevent sticky cotton caused by whitefly.

“The trapping by CDFA has been very extensive and very informative. It gives us a clue as to where sticky cotton issues may arise and allows us to address it quickly,” said Williams.

With cotton acreage declining, revenue for the cotton pest control board PBW program has been declining.

“The board was facing budgetary constraints and was looking to cut whitefly trapping. We encouraged them to stay with the program and they accommodated us. Every cotton grower in the San Joaquin appreciates that very much.

“And, I might add Jim Rudig has done a fantastic job with the program,” he said. Another critical element in keeping PBW at bay is a mandatory plowdown regulation to reduce overwintering habitat for the pest.

Conservation tillage is a new technology several SJV growers are trying and in that system, complete plowdown may not be possible.

“The board and the CDFA people did not stonewall these efforts. Instead they adopted some rules that will allow growers to experiment with conservation tillage without compromising the integrity of the pink bollworm program,” said Williams. “That is the kind of flexibility and continued support for the cotton industry that has been repeatedly displayed by CDFA and the board.”

While the majority of the funds collected has been to support SJV pink bollworm suppression, southern California cotton growers have not been ignored. The board has funded research there over the years.

Ironically, the next and possibly final chapter of pink bollworm story in the western United States and Mexico may be written in southern California along with Arizona, New Mexico, far west Texas and northern Mexico where the pink bollworm has been a constant threat since the mid-1960s.

Growers in these area have been able to stay in the cotton business with the use of pheromone confusion and reduced pesticide use. Now eradication may be possible.

“Bt cotton could be the final piece of the puzzle that will allow us to truly consider eradicating the pink bollworm from the U.S. and Mexico,” said Shropshire. Pheromones and Bt cotton have reduced pink bollworm populations in many areas to levels where massive sterile release drops like are done each year in the San Joaquin can possibly eradicate pink bollworm by overwhelming native populations.

Bob Hull is a long time Palo Verde Valley cotton grower who was a young man just out of college when pink bollworm greeted his return to the family farm near Blythe, Calif.

“There were airplanes flying all over the place when I came back to the farm. I did not know what was going on,” he said. He quickly found out and also found himself in a leadership role of talking to growers about area-wide programs to keep the PBW at bay.

“Bt cotton is keeping us in the cotton business today. Without that technology, cotton would be little more than a rotation crop,” said Hull, a member of the National Cotton Council Pink Bollworm Action Committee, which has been the focal point of the emerging eradication program.

Sterile moths for this eradication effort will come from the rearing facility built in Phoenix 10 years ago with California cotton grower money.

“Wally and the board came through in 1994 with support to build a new state of the art 60,000-square foot rearing facility in Arizona that has allowed us to exponentially increase our rearing capacity and scientific knowledge,” said Staten.

“At that time we were hoping to rear 8 million to 10 million insects per day. Today, because of that resource, we expect to turn out 22 million insects per day. It's all been possible because San Joaquin Valley growers had, and continue to have, the foresight to invest in the future. It was a huge unleashing of energy, and the board made it happen,” said Staten.

If the eradication effort in southern California, Arizona, New Mexico, far west Texas and northern Mexico is successful, sterile moth drops would likely end in the San Joaquin. However, trapping would continue.

“The combination of Bt cotton, pheromones and sterile releases is a pretty bright light at the end of the tunnel toward that elusive goal of eradication,” said Shropshire.

Shropshire began his California cotton career in 1954 when he moved to Palo Verde Valley to manage a cotton gin.

e-mail: [email protected]

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