Taking a Second Look at Lygus Bugs in the Pacific Northwest

This project is directed at enhancing our understanding of the epidemiology of the beet leafhopper transmitted virescence agent (BLTVA) by examining the ability of Lygus (Heteroptera: Miridae) bugs to transmit the pathogen to potato, Solanum tuberosum L. In the Columbia Basin of Washington and Oregon, BLTVA, a phytoplasma, is the primary cause of potato purple top disease and is known to be transmitted to potato primarily by the beet leafhopper (BLH), Circulifer tenellus Baker (Heteroptera: Cicadellidae). Plants infected with BLTVA usually express flagging of leaflets, leaves, small stems and swollen nodes. In the summer of 2014, Lygus bugs were observed in the field in association with potato plants expressing purple top symptoms. Currently, it is not known if Lygus bugs are competent vectors of BLTVA. Reports from growers in the region also suggest a decline in the numbers of BLH in potato fields while Lygus bugs are more abundant in potato fields than previous years. Thus, the present study evaluated: (1) the abundance and species composition of Lygus bugs in commercial potato in the PNW, (2) the incidence of BLTVA in Lygus in commercial potato fields and (3) whether Lygus harbors the same strain of BLTVA as symptomatic potato plants.