Aphids (Hemiptera: Aphididae) associated with rhubarb ( Rheum spp.) in the Matanuska Valley, Alaska: species composition, seasonal abundance, and potential virus vectors

Culinary rhubarb, Rheum spp., is one of the priority crop species curated by the United States Department of Agriculture (USDA) Agricultural Research Service (ARS) in Palmer, Alaska. Water—pan traps in commercial rhubarb in the Matanuska—Susitna River Valley near Palmer and in the USDA ARS Rheum gerrnplasm collection caught aphids belonging to eight species: Aphis helianthi Monell; Chaitophorus neglectus Hottes and Friso, Euceraphis betulae (Koch); Hayhurstia atriplicis (L.); Macrosiphum euphorbiae (Thomas); Myzus persicae (Sulzer); Pemphigus spp. ; and Rhopalosiphum padi (L.). Only three of the species ( M. euphorbiae , M. persicae , and R. padz ) collected in water— pan traps were also handpicked from rhubarb plants. The bird cherry—oat aphid, R. padi , was the most abundant species collected in water-pan traps and from rhubarb plants. Based on their disease transmission capability, A. helianthi , M. euphorbiae , M. persicae , and R. padi , can be considered to be of potential economic importance to rhubarb production in Alaska.