ARS | Publication request: THE BEET LEAFHOPPER (HEMIPTERA: CICADELLIDAE) TRANSMITS THE COLUMBIA BASIN POTATO PURPLE TOP PHYTOPLASMA TO POTATOES, BEETS, AND WEEDS

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 30, 2006
Publication Date: April 3, 2006
Repository URL: http://hdl.handle.net/10113/1356
Citation: Munyaneza, J.E., Crosslin, J., Upton, J.E. 2006. The beet leafhopper (Hemiptera: Cicadellidae) transmits the columbia basin potato purple top phytoplasma to potatoes, beets, and weeds. Journal of Economic Entomology. 99(2): 268-272

Interpretive Summary: The beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma was identified as the causal agent of the potato purple top disease outbreaks that recently occurred in the Columbia Basin of Washington and Oregon and caused significant losses to the potato industry. This phytoplasma was previously found to be associated almost exclusively with the beet leafhopper, suggesting that this insect is the probable vector of BLTVA in this important potato growing region. However, no studies have been conducted to prove that this insect actually transmits the BLTVA phytoplasma to potatoes and several other plants that are found in the vicinity of potato fields and that are potential hosts to both the beet leafhopper and BLTVA phytoplasma. Research was conducted by researchers at the USDA-ARS at Wapato and Prosser, WA, to determine if the beet leafhopper transmits the BLTVA phytoplasma to potatoes, beets, and selected weeds. Eight potato cultivars, including Russet Burbank, Ranger Russet, Shepody, Umatilla Russet, Atlantic, FL 1879, FL 1867, and FL 1833, were exposed for a week to BLTVA-infected beet leafhoppers. After exposure, the plants were maintained outdoors in large cages and then tested for BLTVA using PCR after 43 or 52 days. Results showed the leafhoppers transmitted BLTVA to seven of the eight exposed potato cultivars. Beet leafhoppers also transmitted BLTVA to beets and several weeds. This is the first report of transmission of BLTVA to potatoes, beets, and four of the weeds species studied. This information is very important in designing effective management strategies to reduce incidence of the potato purple top disease in affected areas by focusing monitoring and control efforts on the beet leafhopper and its wild plant hosts.

Technical Abstract: Experiments were conducted to determine if the beet leafhopper, Circulifer tenellus Baker, transmits the purple top phytoplasma to potato (Solanum tuberosum L.), beets (Beta vulagaris L.), and selected weed hosts. The beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma was identified as the causal agent of the potato purple top disease outbreaks that recently occurred in the Columbia Basin of Washington and Oregon. The phytoplasma was previously found to be associated almost exclusively with the beet leafhopper, suggesting that this insect is the probable vector of BLTVA in this important potato growing region. Eight potato cultivars, including Russet Burbank, Ranger Russet, Shepody, Umatilla Russet, Atlantic, FL 1879, FL 1867, and FL 1833, were exposed for a week to BLTVA-infected beet leafhoppers. After exposure, the plants were maintained outdoors in large cages and then tested for BLTVA using PCR after 43 or 52 days. The leafhoppers transmitted BLTVA to seven of the eight exposed potato cultivars. Sixty four percent of the exposed plants tested positive for the phytoplasma. In addition, 81% of BLTVA-infected potato plants developed distinct potato purple top disease symptoms. Beet leafhoppers also transmitted BLTVA to beets and several weeds, including groundsel (Senecio vulagris L.), shepherd’s purse (Capsella bursa-pastoris (L.) Medik), kochia (Kochia scoparia (L.) Schrad), and Russian thistle (Salsola kali L.). This is the first report of transmission of BLTVA to potatoes, beets, and these four weeds species. Results of the present study prove that the beet leafhopper is a vector of the potato purple top disease.