For the last half century, the pesky pink bollworm (PBW or ‘pinkie’) insect - Pectinophora gossypiella - has attacked cotton bolls, damaged fiber and seeds, and reduced yields in fields in California, Arizona, New Mexico, and West Texas, plus the states of Calexico and Chihuahua in northern Mexico.
Now, climb aboard cotton’s time warp machine to 2014.
“Today, there has not been a native fertile moth captured in a trap across the four-state area and northern Mexico for two full years,” said Clyde Sharp, a Roll, Ariz. cotton grower who has helped lead PBW eradication efforts at the state and national levels for almost a decade.
This is the region’s first year of eradication of the insect. Cotton growers in the four-state area are possibly three years away from full eradication; if the crop-destroying insect fails to rear its ugly head again.
This accomplishment is truly a feat for the history books.
“I believe that we have accomplished eradication,” Sharp declared to the large cotton industry crowd gathered for the Arizona Cotton Industry Meeting held in Flagstaff, Ariz. in June.
“Pink bollworm eradication is a great story to tell,” Sharp said. “It’s a wonderful story when you consider we’re dealing with near eradication across the entire southwestern U.S.”
The last native pinkie find was found in an insect trap in Yuma County, Ariz. in May 2012. The Yuma area is considered ground zero for pinkie movement from Mexico into the U.S. and then movement elsewhere in the states.
Also chiming in on the near eradication fete is Patrick Acres, entomologist at the California Department of Food and Agriculture (CDFA) and program manager of the California Pink Bollworm Control Program.
“I am astounded by the success of the pink bollworm eradication program,” said Acres, just starting his second year at the California PBW helm. He succeeds former director Jim Rudig, now retired.
“It’s a historic moment,” Acres told Farm Press by phone. “As an entomologist, this would only be the third time in the history of entomology where an insect was fully eradicated.”
The other two eradicated pests include the screwworm found in the livestock industry and the boll weevil in cotton; the latter a major pest for much of the Cotton Belt. In the southwestern states, the pinkie has caused the most economic loss for cotton growers than any other pest.
The pink bollworm was first found in the western Cotton Belt in the 1960s. Early pest treatments included standard insecticide sprays. The insect population exploded – so did crop losses to growers.
“From the 1960s to the 1990s, cotton growers in Arizona and southern California who did not practice pink bollworm control lost about one quarter to one-half bale per acre to the insect,” according to Larry Antilla, retired director of the Arizona Cotton Research and Protection Council (ACPRC).
Antilla now works part time for the council under the leadership of new council director Leighton Liesner.
The ACRPC is the entity charged with leading the Arizona pinkie attack.
The pinkie is a small insect but a menace for cotton growers. The female lays eggs on or near the cotton boll. The microscopic larva burrows into the boll. When near maturity, the larva chews through the wall of the boll and falls to the ground to finish development into a moth. The exit hole allows fungi and bacteria entry into the boll to create boll-damaging infection.
In the larval stage, the young insect chews through lint to feed on the seeds. Cotton is grown for fiber and seed oil.
Sterile moth success
Area wide pinkie management began in the 1990s, first with host-free periods followed by the implementation of pheromone technology, Bt (genetically modified) cotton, plus sterile PBW moth releases over cotton fields in the four-state region.
The moths are raised at the USDA moth rearing facility in Phoenix, Ariz. Male and female insects are sterilized during the process. Moths are released by airplane over cotton fields where the steriles attempt to mate with native moths which ultimately fail. The native’s life cycle ends without reproduction.
“In the fight against pinkies from the 1960s to the 1990s, growers and industry spent nearly $1.3 billion on pesticide and application costs against the insect - about 72 million acre equivalents,” Antilla said.
With the western Cotton Belt in its first year of the formal eradication process, the goal is for no native finds for the next three years. If this occurs, the National Cotton Council’s (NCC) Pink Bollworm Action Committee could vote for full eradication status of the pest in the western cotton states in 2017.
The current chairman of the committee is cotton grower Dennis Palmer of Thatcher, Ariz.
Many cotton growers, industry leaders, associations, and state and federal governments jumped feet first into full-scale pink bollworm eradication efforts. Sharp’s leadership at the state and federal levels has spanned about a decade.
Sharp is the past president of the Arizona Cotton Growers Association, past chair of the ACRPC and the NCC’s American Cotton Growers. He holds other prominent cotton leadership positions today.
For his leadership contributions to cotton and sustainability on the Sharp family farm and in the U.S. cotton industry, Sharp was awarded Western Farm Press’ 2014 High Cotton Award in New Orleans, La. in January.
Despite the eradication efforts so far, Sharp believes full eradication may not be achieved by the 2017 date.
“I honestly believe we will have a find,” Sharp said. “It’s a matter of ‘when’ not ‘if’ a native is found. It will likely be carried into the U.S. from Mexico by winds or as a ‘hitch hiker’ on a vehicle.”
If new native pinkies are discovered, the ACRPC protocol will include insecticides targeted at the new find area, along with strong encouragement to local growers to grow only Bt cotton, and sterile moth releases.
However, the council no longer has planes available for sterile moth release. Could unmanned drones be the answer?
Sharp said, “The council is considering drone use to drop 70,000-100,000 sterile moths over a find area to greatly reduce natives’ ability to multiply, reproduce, and come back down the road to haunt us.”
The veteran leader says it would be best to rid cotton of the pest once and for all, before a NCC full eradication declaration, and be done with the pest once and for all.
PBW in Mexico
Currently, the closest moths to the western states are located in Torreon, located about 400 miles south of the Texas-Mexico border in an area not included in the bi-national eradication program.
“The cotton industry is double trapping around Pima cotton fields within a 50 mile radius of the border,” Sharp said. “If re-infestation occurs, it will likely be in Pima since pinkies love Pima.”
Yet the pinkie is an equal opportunity cotton feeder, Acres adds. The insect also feeds on Upland cotton and other crops.
According to Liesner, a 50-mile buffer zone from the Mexican border into Arizona includes one trap per 10 acres on non-Bt cotton and one trap per 40 acres in Bt acreage. The acreage north of the 50 mile zone has one trap per 20 acres of non B-t cotton and one trap per 160 acres of Bt.
Liesner told the cotton crowd that Pima acreage in Arizona this year increased almost 900 percent, in part due tied to pinkie eradication efforts. Pima acreage increased from about 1,500 acres last year to 15,000-plus acres this year.
At one time, Arizona was the nation’s top Pima cotton producer with the balance scattered across the western Cotton Belt. The pink bollworm led to the near demise of Pima plantings in the Grand Canyon State. Today, 95 percent of the nation’s Pima crop is grown by California growers.
According to Acres, the last two native moths trapped in California were found in 2011 – one each in the San Joaquin Valley and Imperial County. No natives have been found since.
“We are approaching eradication in California,” Acres said.
Like the other regional states, California is a poster child for effective area wide eradication.
Southern California fertile pink bollworm moth captures totaled 416,000 captures in 2007 – 15,000 in 2008 – 6,100 in 2009 – 135 in 2010 – and two finds in 2011.
CDFA has about 500 traps covering 15,000 acres in the southern California desert and San Joaquin Valley.