What is in this article?:
- Research advances reduce lygus damage in cotton
- Lygus risk factors
- University of California research has placed the lygus bug squarely in prevention crosshairs to help cotton producers reduce yield loss and keep greenbacks in their wallets.
- “It takes a village” (an agricultural community) to better manage lygus, says Pete Goodell, UC IPM Cooperative Extension Advisor.
- Effective lygus management involves landowners, producers, pest control advisers, biological and physiological experts, and others.
- Major risk factors for lygus movement include distance, strength, timing, and landscape configuration.
University of California researchers, from left, Pete Goodell, Carol Frate, Shannon Mueller, and Larry Godfrey.
Lygus risk factors
“Unmanaged safflower is a source of lygus and a very high-risk crop to cotton,” Goodell explained. “For safflower planted near cotton, it’s important to treat safflower with insecticide to reduce pest numbers before the insect moves into cotton.”
The California Department of Agriculture reports about 53,000 acres of safflower were grown in California in 2011, mostly for oil for biofuel.
Goodell’s UC IPM career began in 1981. He initiated lygus surveys to estimate lygus population buildups in the SJV West Side foothills during the spring months before the insect’s mass movement to the east into farm fields.
In 2009, Goodell and other entomologists tapped satellite remote sensing technology to develop maps of lygus movement from the foothills. The system worked fine when skies were clear. However, cloudy days prevented satellite cameras from seeing the ground to take photos so the effort was abandoned.
Entomologists utilize short- and long-term weather forecasts to help predict lygus numbers. An El Niño wet winter weather pattern can deliver a greener landscape and higher lygus numbers. A La Niña winter keeps the foothills brown with less food for insect development.
Goodell chuckled and said, “When the hills are brown, hopes abound. When green in May prepare to pay.” The analogy drew laughter from the crowd.
The major risk factors for lygus movement, Goodell said, include distance, strength, timing, and the landscape configuration.
There is an inherent limitation on how far a lygus bug can fly since it is not considered a long-distance flyer. Strength pertains to the condition of the host source.
“Distance and strength are interrelated,” Goodell said. “If you have a strong source and the cotton is close by then this will increase the risk versus the strong source being further away.”
Timing involves when a crop or weed host releases the insect. If the source is harvested earlier than cotton, lygus will leave to feed in cotton.
The landscape configuration involves all crops grown in the cotton-growing area. A sink host can help absorb lygus and slow its movement into cotton.
Alfalfa can serve as a source and a sink for lygus. When alfalfa is cut, the insect marches out of alfalfa toward another host. A managed strip habitat in alfalfa can act as a sink and reduce lygus movement out of alfalfa.
These and other more detailed findings have been gained through the USDA Risk Avoidance and Mitigation Program project, or RAMP. The five-year, $2.5 million project has assisted more than a dozen researchers in California, Arizona, New Mexico, and West Texas in studying lygus biology and how their respective local landscapes impact multiple crops.
With this collective information, the next phase is getting the critical information out to cotton growers to better understand how multiple local issues impact lygus and cotton.
Over the last several years, Goodell and University of Arizona IPM Specialist Peter Ellsworth created a computer gaming software system called Lygus Simulation Training Environment. The video game allows producers and others to use computers in a meeting setting to select their crops for the next crop year and actually see the crops their neighbors intend to plant.
The software then predicts lygus outbreaks based on crop placement. Producers can readjust their planting intentions to reduce lygus numbers and help their neighbors growing cotton.
The lygus-cotton video game was developed for producers in the SJV, Arizona, and West Texas. The game can be tweaked for other areas of the Cotton Belt.
The game was tested with a group of cotton growers in Marana, Ariz., in June 2011. The Lygus Symposium took the game for a spin. Both groups gave the interactive game a thumbs up.
The next step is to roll the gaming simulation out at Extension grower meetings and perhaps online.
The gaming program has not been launched due to the lack of funding. Ellsworth and Goodell are seeking funds to place the program in the hands of growers.