Washington State University Mount Vernon, Washington, United States
The presence of thrips (Insecta:Thysanoptera) in Alaska grown peonies (Paeonia lactifloria ‘Sarah Bernhardt’) represents a significant trade barrier for the rapidly growing industry when shipping to international markets. In 2018, a multi-year USDA FAS TASC grant was awarded to the State of Alaska Division of Agriculture to determine the thrips fauna infesting Alaska peonies and explore control strategies. Taxonomic studies focused on the determination of which species of thrips were present and increasing the turnaround of identifications using morphological characters. In 2019, peony buds were shipped from Alaska to the Washington State University NWREC. Buds were dissected under a stereomicroscope by removing leaves, bracts, sepals, and petals to expose thrips and by knocking thrips from reproductive structures. Data were collected for each thrips specimen and included the following categories: unique ID #, life stage, location in peony bud, body color, morphospecies and miscellaneous notes on biology or behavior. Specimens were subjected to a non-destructive DNA extraction protocol and mounted on microscope slides for identification. A provisional morphological key to adults was constructed and consisted of all thrips species recorded from peonies in Alaska. In total, 272 adult and larval thrips were collected from 556 dissected buds. Six species were identified from 2019 Alaska peony samples: Frankliniella fusca (Hinds), Frankliniella intonsa (Trybom), Frankliniella occidentalis (Pergande), Thrips fallaciosus Nakahara, and Thrips vulgatissimus Haliday. Objectives for 2020 included the development of a Lucid key to the thrips associated with Alaska grown peonies and sampling additional geographic localities and peony cultivars.
