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KAC Citrus Entomology
University of California
KAC Citrus Entomology


Yellow sticky cards

Yellow sticky card Citrus Research Board
Yellow sticky cards are used by the California Department of Food and Agriculture and the Citrus Pest and Disease Prevention Program to trap adult psyllids flying about citrus trees.  The traps are more attractive when there isn't any new young flushing leaves on the tree to distract the psyllids. 

Psyllid Identification

Look closely at the psyllid wings.  The edges of the wings are brown with a clear break in the pattern.  This is the best way to recognize ACP compared to other small insects. This printable pdf file will show you photos of all stages of the psyllid. Recognizing ACP stages

Visual search of new flush

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.

Inspect trees for psyllids every time you see new leaf flush
Inspect trees for psyllids every time you see new leaf flush
Nymphs with waxy tubules
Nymphs with waxy tubules

ACP Sampling methods for PCAs and growers

PDF print outs of Sampling sheet.

Uniform sampling methods are needed 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.

  1. Use a white clipboard with a grid, or tape white paper with a grid on it to the bottom of a translucent clipboard.  The grid will help you count the psyllids more quickly.  Spray the nonpaper side of clipboard with a squirt of Dawn 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. 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.

Sampling sheet

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