|Jensen, Andrew - WA STATE POTATO COMM|
|Hamm, Phillip - OSU, HERMISTON|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 31, 2007
Publication Date: N/A
Interpretive Summary: The beet leafhopper was recently found to be the major vector of the Columbia Basin potato purple top phytoplasma, causal agent of the potato purple top disease that recently occurred in Washington and Oregon and caused significant losses to the potato industry. Scientists at the USDA-ARS Laboratory, Wapato, WA, Washington State Potato Commission, and Oregon State University at Hermistonconducted research to determine the seasonal occurrence and abundance of the beet leafhopper in the Columbia Basin of Washington and Oregon. It was found that the beet leafhopper was abundant in the study area and moved to commercial potato fields from weeds in the vicinity in early summer. Several other economically important leafhoppers species were found in the study area. Information from the present study will help growers in the Columbia Basin make effective management decisions to reduce incidence of purple top disease in potatoes by monitoring the beet leafhopper and making timely insecticide applications to control this insect.
Technical Abstract: In 2003, 2004 and 2005, leafhopper sampling was conducted in the Columbia Basin of Washington and Oregon to determine the seasonal occurrence and abundance of the beet leafhopper, Circulifer tenellus Baker, the primary vector potato purple top disease in this major potato producing region of the United States. Leafhoppers were sampled using sweep nets and yellow sticky traps at weekly intervals in and around potato fields throughout the Columbia Basin from April to October. Leafhopper species in the samples were sorted, identified, and counted. The beet leafhopper was very abundant in weeds near potato fields from mid-April to mid-October and had at least 3 generations per year. The beet leafhopper moved into potato fields in mid-May and was present in potatoes throughout the remainder of the growing season. This leafhopper was more abundant in potatoes in early May to early July, suggesting that potatoes more likely are infected with the purple top disease during early summer; however, it is not clear how far into the growing season that potato infection occurs. Several other leafhopper species were found to be abundant in the study area and included economically important species such as Macrosteles spp., Ceratagallia spp., and Colladonus spp. Most of the leafhopper species found in weeds in the vicinity of potatoes were also present within potato fields.