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


The goal: To determine if Asian citrus psyllid (ACP) is in your grove and what impact the treatments you are applying have on ACP densities.  Yellow sticky card traps are not very attractive to psyllids.  Visual and tap sampling methods are better for detecting psyllids and population monitoring. 

Visual Survey: The best way to find psyllids is to examine tiny new leaves as they are developing and look for signs of adult psyllids or the nymphal stage with its waxy tubules.  The adults must lay their eggs in new flush.  However, when population densities are low, psyllids may be difficult to find.

Tap Sampling: Uniform sampling methods are used to compare infestations in commercial citrus orchards. The current protocol is to sample 10 trees each on the north, east, south, west borders (rows/trees) of the orchard and in the center of the orchard (total of 50 trees).  The psyllid prefers borders and so the focus is on the outside edges of orchards.  Edges are defined as breaks in citrus plantings, generally the size of a road.  Enter the data on a sample sheet.

  1. Tap Sampling: Use a clipboard with a white piece of paper inside a plastic sheet.  Spray the plastic sheet with a mixture of a squirt of detergent mixed in a ½ liter of water.  ACP knocked onto the clipboard will stick in the solution, giving you time to see, identify and count them.  Hold the clipboard under a branch and strike the branch 3 times with a 12” section of pvc pipe (or other device).  Then count the number of winged adult psyllids collected on the clipboard.  Scrape the psyllids off of the clipboard after each count and re-apply the liquid as needed.  To see a video demonstration, click here  Tap sample demonstration
  2. Visual survey: Examine 1 young leaf flush per sample tree for all psyllid stages (eggs, nymphs, adults).  Split the numbers on the sample sheet by stage. Example; 1/0/3 denotes 1 egg, 0 nymphs and 3 adults were found.
  3. Describe the state or stage of the leaf growth on the tree as feather flush, growing flush or fully expanded leaves. This provides information about whether the flush is in a suitable state for immature stages.


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