University of California Agriculture and Natural Resources outlined on Apr. 13 the use of biological control agents to manage invasive pests across California. The organization highlighted the role of beneficial insects such as weevils and parasitoid wasps in reducing populations of harmful species like yellow starthistle, ash whitefly, Asian citrus psyllid, and pink hibiscus mealybug.
These efforts are significant because invasive pests can threaten local ecosystems, agriculture, and landscapes. Biological controls offer a targeted alternative to chemical pesticides by using natural enemies to suppress pest populations.
Researchers from the United States Department of Agriculture and the California Department of Food and Agriculture have released rosette weevils to weaken or kill yellow starthistle plants throughout the state. The rosette weevil was approved for release in 2019, with ongoing efforts to establish its presence. In addition, parasitoid wasps such as Encarsia inaron have helped keep ash whitefly populations low since their introduction in the late 1980s—a success story estimated to save $2 million annually by reducing pesticide use.
Other parasitoids like Tamarixia radiata were introduced in 2011 to combat Asian citrus psyllid infestations across Southern California. These wasps act both as predators and parasites but can be less effective when ants protect their prey. Anagyrus kamali has also been released against pink hibiscus mealybug infestations limited so far to Riverside and Imperial counties.
The University remains alert about new threats such as spotted lanternfly, which is spreading rapidly on the East Coast but has not yet reached California. Researchers are monitoring potential biocontrol options including fungi and additional parasitoids while encouraging public vigilance through educational courses.
University of California Agriculture and Natural Resources secures funding through public contributions for its programs according to its official website. The organization promotes sustainable practices that strengthen resilient ecosystems and economic vitality according to its official website. It utilizes nine research and extension centers representing diverse ecosystems according to its official website and is recognized for linking research with community needs according to its official website. As part of the University of California system managing Cooperative Extension services according to its official website, it conducts over 33,000 educational events each year with more than 18,000 volunteers involved according to its official website.
Looking ahead, experts stress that early detection by residents will be crucial for managing future pest invasions using biological control strategies.