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United States Department of Agriculture

Agricultural Research Service

Research Project: Sustainable Pest Management Strategies for Arid-land Crops

Location: Pest Management and Biocontrol Research

Title: Effects of local and landscape factors on population dynamics of a cotton pest

Authors
item Carriere, Yves -
item Goddell, Peter -
item Ellers-Kirk, Christa -
item Dutilleul, Pierre -
item Naranjo, Steven
item Ellsworth, Peter -

Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 31, 2012
Publication Date: June 29, 2012
Repository URL: http://handle.nal.usda.gov/10113/57478
Citation: Carriere, Y., Goddell, P., Ellers-Kirk, C., Dutilleul, P., Naranjo, S.E., Ellsworth, P.E. 2012. Effects of local and landscape factors on population dynamics of a cotton pest. PLoS One. 7(6):e39862.doi:10.1371/journal.pone.0039862.

Interpretive Summary: The plant bug Lygus hesperus is a major pest of cotton in the western U.S. The pest is highly polyphagous and readily disperses among various crop and non-crop habitats in the landscape but little is known about effects of landscape diversity on this pest’s metapopulation dynamics. Using spatially referenced samples from a large cotton growing region in central California, we evaluated how the spatial arrangement of crops and uncultivated habitats affect population density of Lygus in cotton. During early and late season over three years we examined source and sink effects of six crops and uncultivated habitats along with variation in insecticide applications and flowering date. Factors with consistent effects included cotton and uncultivated habitats as sinks, seed alfalfa as a source, and flowering date that was positively associated with Lygus density. Safflower, forage alfalfa, tomato, sugar beet and insecticide applications had variable and inconsistent effects. A multiple regression model including the four consistent factors from the 1st two years significantly predicted Lygus density in cotton in the 3rd year at a scale of 2.75 km and accounted for 52% of the variation in density. These results suggest that manipulation of crop placement and planting date has the potential to regulate Lygus populations in cotton and may allow producers to better manage pests such as Lygus by careful planning on their farms and through better cooperation with neighboring producers.

Technical Abstract: Local diversification of vegetation is used extensively to reduce pest pressure in crops, but little is known about effects of landscape diversity on pest metapopulation dynamics. Many polyphagous pests sequentially use crops and uncultivated habitats in landscapes dominated by annual crops. As these habitats may consume or export individuals, understanding the scale and temporal variability of source and sink effects is critical for manipulating landscapes to enhance pest control. We evaluated how the spatial arrangement of crops and uncultivated habitats affect population density of Lygus hesperus in cotton in California. During early and late season over three years we examined source and sink effects of six crops and uncultivated habitats along with variation in insecticide applications and flowering date. Factors with consistent effects included cotton and uncultivated habitats as sinks, seed alfalfa as a source, and flowering date that was positively associated with Lygus density. Safflower, forage alfalfa, tomato, sugar beet and insecticide applications had variable in inconsistent effects. A multiple regression model including the four consistent factors from the 1st two years significantly predicted Lygus density in cotton in the 3rd year at a scale of 2.75 km and accounted for 52% of the variation in density. These results suggest that manipulation of crop placement and planting date has the potential to regulate Lygus populations in cotton.

Last Modified: 7/28/2014