Successful Area-Wide Management of the Asian Citrus Psyllid1 in Southwestern Sonora, México

Abstract

The Asian citrus psyllid, Diaphorina citri Kuwayama, was detected in March 2006, on citrus plants in the residential area of Ciudad Obregon Sonora. A year later, it was observed at Guaymas and Hermosillo, Sonora. Since its discovery at Ciudad Obregon, surveys determined its regional dispersal to commercial plantations of Citrus. In 2010, an area-wide strategic management plan was established to keep abundance of Asian citrus psyllid to a minimum and lessen risk of establishment of Huanglongbing in the State of Sonora. The plan was successful in keeping abundance of Asian citrus psyllid low with no Huanglongbing detected on commercial citrus plants. The plan is based on coordinated effort and mandatory actions in commercial plantations including weekly surveys by yellow sticky traps and stem-tap sampling, two area-wide insecticide applications during the dormant stage (February-March) and again in the fall (September-October), as well as in-season sprays when sampling reveals hot spots. Citrus plants in rural and residential areas also are monitored and sprayed to reduce abundance of Asian citrus psyllids in the region. Results of the area-wide management plan were considered satisfactory 12 years since first detection of Asian citrus psyllid at Sonora. Abundance of Asian citrus psyllids was reduced almost 90% area-wide and no plants with Huanglongbing were detected in surveys of commercial orchards. In 2015, infected psyllids were detected in rural and residential areas of Southern Sonora. Aggressive action was implemented to control Asian citrus psyllids and eliminate at-risk citrus plants. Further surveys and laboratory PCR analysis for Huanglongbing did not show any other infected insects or citrus plants in the area. However, in 2016 infected Asian citrus psyllids were detected in residential areas of Guaymas. Similar measures were taken to eliminate Asian citrus psyllids and potentially infected citrus plants. All infected trees were Mexican limes, Citrus aurantifolia (Christm.) Swingle, a common backyard tree in Mexico. Key components of the systems approach were cooperation of growers, coordinated control actions, and interactions with plant-protection authorities, researchers, and government support. However, migratory influx of bacterialiferous adult psyllids from Southern Baja California and Sinaloa remains a high risk for introduction of Huanglongbing to Sonora.