Potato Psyllid, A Pest of Potato in the Western U.S.

Potato crisps exhibiting Zebra chip, thought to be caused by a bacterium that converts potato starch to water-soluble sugar that caramelizes during the cooking process, creating black lines. Credit: Joseph E. Munyaneza, USDA

The potato psyllid (Bactericera (=Paratrioza) cockerelli)(Fig. 1) is a serious pest of solanaceous crops. It causes direct damage to the plants and also vectors a pathogen known as “zebra chip” (ZC) (Fig 2.), and has been documented in commercial potato fields in the U.S. (Texas, Nebraska, Colorado, Kansas, New Mexico, Arizona, Nevada, and California), Mexico, and Guatemala. The disease was named for the characteristic discoloration in potato chips produced from infected tubers. Potato psyllids have not established east of the Mississippi River. All potato psyllids found in Florida have been interceptions from places known to be infested with the pests.

 

 

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Fig 2. Tubers infected with zebra chip disease show dark, stripelike symptoms in the tissue. Credit:, Joseph Munyaneza, USDA

Adults and nymphs feed by sucking plant juices. Damage is caused by a toxin that the immatures (Fig. 3) produce when they feed. The toxin causes a plant response known as psyllid yellows. Symptoms (Fig. 4) include an upward curling of leaflets nearest the stem on the top part of the plant. As the disease establishes itself, this symptom becomes more evident. Plant yellowing is the most common symptom. The yellowing (in some varieties, purpling) is initially found on the leaf edges.

Fig. 3. Nymphs of various age. Credit: Whitney Cranshaw, Colorado State University, Bugwood.org, #5369801

 

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Fig. 4. Dull fruit color from psyllid infestation. Credit: Whitney Cranshaw, Colorado State University, Bugwood.org, #5369940

Use yellow sticky traps to detect the presence of potato psyllid and initiate leaf sampling. The undersides of leaves can be examined for nymphal stages. Because potato psyllid nymphs can be difficult to see on a potato leaf, planting a few pepper or bean plants in the field can provide an easier way to detect the nymphs.

Click the image for more information about the potato psyllid.

References:

Halbert, Susan and Dixon, Wayne N.  A Pest of Solanceae and Vector of Plant Pathogens Established in the Western USA. Accessed: 6/8/2015 – http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Pest-Alerts/Potato-Psyllid-Bactericera-cockerelli-Hemiptera-Psyllidae

Godfrey, L. D. and  Haviland, D. R. UC IPM Pest Management Guidelines: Potato UC ANR Publication 3463                      Accessed 6/11/2015 – http://www.ipm.ucdavis.edu/PMG/r607300811.html