Asian Citrus Psyllid Distribution and Management
University of California
Asian Citrus Psyllid Distribution and Management

Area-wide treatment programs

Once the psyllid is found in multiple sites, in multiple stages, and it is clear that it is established in a region, the strategy becomes one of keeping ACP populations as low as possible (<0.5 nymphs/flush). ACP treatment efforts should focus on treating 1) in the fall to protect the new flush and to kill adult psyllids as they begin overwintering, 2) again in early spring as the new flushes are forming, 3) during the spring and summer as other flushes appear and as other pests require control. Research is showing that the fall is the most difficult time to control the psyllids, leading to a recommendation of two treatments at that time of year in areas where psyllid pressure is high (coastal and inland southern California). Click on the tabs on the left for specific treatments strategies for the various growing regions: Ventura, Riverside/San Bernardino, Coachella/Imperial Valleys, and San Diego.

Conventional Insecticide Strategy

There are many ACP-effective conventional insecticides (see tab at left). Pyrethroids and neonicotinoids are the most effective and long lasting. In addition, they can act as an anti-feedant, which may reduce the psyllid's ability to transmit the pathogen that causes huanglongbing.  

Organic Insecticide Strategy

The efficacy of organic insecticides, both in terms of the number of insects killed and the persistence of the insecticides is much lower than synthetic insecticides. Organic insecticides require contact with the insect body, and the persistence of organic products is hours to days (not weeks like the synthetics). As a result, they need to be applied more frequently. 

It is recommended that 10 flushes per border be sampled at 2 week intervals throughout the year and treatments applied when psyllids exceed 0.5 nymphs/flush.  

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