CDFA Deploys Parasitic Wasps and Biocontrol Tools to Fight Invasive Citrus Threat

Key Takeaways:

• The California Department of Food and Agriculture (CDFA) is spotlighting biocontrol efforts during Invasive Plant Pest and Disease Awareness Month (IPPDAM) in April.
• CDFA's Citrus Pest and Disease Prevention Division has released more than 34 million Tamarixia radiata wasps across California since 2012 to combat the Asian citrus psyllid (ACP).
• ACP spreads Huanglongbing (HLB), an incurable citrus disease detected in Los Angeles, Orange, San Bernardino, San Diego, Riverside, and Ventura Counties.
• Strict quarantine zones are in place across affected regions, prohibiting the movement of homegrown citrus plants, clippings, or fruit in or out of those areas.
• Residents are urged to inspect backyard citrus trees regularly, control ants near trees, and report suspicious symptoms to CDFA's pest hotline at 1-800-491-1899.

CDFA Marks IPPDAM with Focus on Biological Pest Control

In recognition of Invasive Plant Pest and Disease Awareness Month this April, the California Department of Food and Agriculture (CDFA) is drawing attention to its ongoing efforts to protect California's agricultural and residential landscapes from invasive pests and diseases — including its use of biological control methods.

Tiny Wasps Serve as a Natural Defense Against ACP

Central to CDFA's biocontrol strategy is Tamarixia radiata, a small, stingless parasitic wasp used to suppress populations of the Asian citrus psyllid (ACP). ACP is the invasive pest responsible for spreading Huanglongbing (HLB), a deadly and incurable citrus plant disease.

Tamarixia wasps feed on ACP nymphs, preventing the pest from reaching maturity and reproducing. The wasps pose no threat to humans or pets.

• Control ants near citrus trees. Ants disrupt Tamarixia‘s ability to parasitize ACP. Residents should apply safe ant control products around the base of citrus trees and throughout the yard. The University of California Agriculture and Natural Resources offers guidance on appropriate options.
• Inspect backyard citrus regularly. Residents should look for signs of ACP or HLB, including yellow shoots, mottled leaves, or misshapen fruit, and report unusual symptoms to CDFA's pest hotline at 1-800-491-1899.
• Support agricultural crews. Cooperating with agricultural officials conducting monitoring or treatment activities helps accelerate early detection of ACP and HLB.
• Dispose of plant material safely. Citrus clippings should be dried or double-bagged before being removed from the property to prevent ACP from spreading via plant debris.