Pepper Weevil Research Project
An Emerging Pest of Peppers in the Central Coast of California
In 2016 and 2017, 60-63 pepper fields in the region were monitored from May-November using pheromone-baited yellow sticky traps. Abundance of adults peaked during the production season. In 2016, the peak was in mid-September. The first of two peaks in 2017 was in June at the beginning of the season and the second was in September-October.
During June-July, when pepper fields were sprayed with insecticide, few weevils, about two per field, were counted. Starting in August (which overlapped with decreased application of insecticide), fields became very infested until the end of October in 2016 and mid-November in 2017. Peak numbers of adults captured in late season varied between years, with 330 and 463 captured in September 2016 and 2017, respectively. From October onward in both years, fruit drop with various stages of weevils inside was observed in some infested fields.
Our Goals with this Project Were
1.
Investigate if the pepper weevil (Anthonomus eugenii) is established in the Santa Clara pepper production areas.
2.
Determine the season-long incidence and abundance of pepper weevil in commercial pepper fields in Santa Clara and San Benito Counties.
Key Project Findings
Early monitoring helps determine weevil treatment options.
Adult weevils can be detected by using pheromone-baited yellow sticky traps. Pepper weevils are most attracted to yellow and Trécé dual-lure system is the most attractive lure. Inspecting a yellow sticky trap is equivalent to inspecting 50 terminal buds.
Timely insecticide sprays minimize number of weevil life cycles.
Insecticide sprays to manage weevil populations are recommended in early season (May-June) to minimize the number of life cycles, in mid (mid-July to August) and late-season (August-November) to discourage increase in weevils in fields.
Limiting adult weevil movement between farms is critical.
If pepper weevil is being reintroduced each year, preventing adults spreading from processing and packaging facilities by sanitizing empty bins before reusing or avoiding planting peppers in fields near pepper-processing facilities is critical.
Project Team Members
Project Collaborators
Pepper Growers
Pepper Growers in Santa Clara and San Benito counties who allowed us to monitor their fields for pepper weevils.
Nutrien Ag Solutions
Nutrien Ag Solutions helped us with monitoring for pepper weevils in grower fields in the region.
Farm Bureau
Santa Clara County Farm Bureau helped us with contacting key pepper grower collaborators in the region.
Aparna Gazula
Project Principal Investigator Small Farms & Specialty Crops Advisor with UC Cooperative Extension in Santa Clara, San Benito, and Santa Cruz counties.
Elisa Mineo
Former Junior Specialist with UC Cooperative Extension Small Farms & Specialty Crops Program in Santa Clara, San Benito, and Santa Cruz counties. She is currently a GIS Analyst at Aurea Imaging in The Randstad, Netherlands.
Shimat V. Joseph
Former IPM Entomology Advisor with UC Cooperative Extension in Monterey County. He is currently an Assistant Professor in the Department of Entomology at University of Georgia, Griffin.
Project Funding
Provided the grant funds for conducting the two year research project.
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