This week’s piece is adapted from comments by GFN Board member Ted Sheely from California at the recent announcement at the US Dept of Agriculture that after years of effort the pink bollworm has been declared eradicated in the United States. This had been a devastating pest that at one time nearly wiped out the cotton industry in the country.
The Challenge: The pink bollworm, native to Asia, began to infest US cotton crops in the 1920’s. By 1952, the small, gray moth was infesting cotton fields across Texas, Arizona, Louisiana, Oklahoma, New Mexico and Arkansas. The female moth lays eggs in a cotton boll. When the larvae emerge from the eggs, they begin feeding on the boll, creating damage by chewing through the cotton lint to feed on the seeds.
Fighting the pest to save the cotton: The California Pink Bollworm Program was started in 1967, led by iconic people within the cotton industry, focused on the use of techniques other than standard insecticides. We started with mandatory host-free periods, including plowdown dates that required a field to be plowed under as soon as a crop is harvested to stop the life cycle of the next generation of bollworms. The program began to use pheromones to keep the moths from being able to find their mates and in the 1970’s, the program added the use of sterile pink bollworms moths, to prevent egg laying by wild moths. Together, these techniques were able to keep the moth from ever becoming established in the San Joaquin Valley, where most of the cotton is grown in California.
In the early 2000’s, the development and commercialization of Bt cotton offered an opportunity to completely eradicate the pink bollworm. This cotton contains a protein that is toxic ONLY to the larvae of moths. The widespread planting of Bt cotton created an opportunity to wipe out pink bollworm when combined with the other techniques already in use.
Innovative technology works: Before the eradication program began, California officials were trapping about 400,000 moths per year in Southern California. In 2007, the first year of the eradication program, over 410,000 moths were trapped. By 2008, the number dropped to about 16,000 – a 96% reduction in one year! The last moths were caught in 2011. California has had zero pink bollworm moths since 2012, and all western states and northern Mexico reached zero moths in 2013.
Celebrating technology and making history: Today, we mark a truly historic moment of time in California agriculture. Working together to protect California cotton from this devastating pest, we stand together as the USDA announces pink bollworm eradication. The first year my brother and I took over our Arizona farm from our father, we almost lost the farm due to the devastation caused by the pink bollworm. To be able to say today that it has been eradicated in California and across the U.S. is gratifying, exciting and truly a product of hard work, vision and persistence by so many. Innovative technology protects crops, builds communities and serves as a powerful tool that can feed, fuel and clothe the world when put into the hands of farmers who can use it safely and effectively as envisioned and designed.
See also ‘Genetic engineering and IPM aid pink bollworm eradication‘ (Nov 12, 2018 – Western Farm Press)