Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-22000-022-026-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 25, 2022
End Date: Dec 31, 2024
Objective 1) Identify the overwintering and secondary host plant species of winged green peach aphids landing in commercial and seed potato fields within the Columbia Basin and Eastern Idaho. Objective 2) Evaluate the potential of non-crop plants as reservoirs for aphids and/or virus.
Obj. 1) We will use gut contents analysis to determine which plant species winged green peach aphids have fed upon, and thus, likely originated from throughout the growing season for two years. Winged aphids will be collected as they land within five commercial potato fields scattered throughout the Columbia Basin and three seed potato production fields in Eastern Idaho every 7 d during spring (May), summer (June/July), and fall (August/September) flights using yellow pan traps. We will process 30 specimens per location, pooling them if >30 are collected, by extracting DNA and submitting ITS and trnF regions for PacBio sequencing. Sequencing results will then be used to identify plant species using the NCBI database. We will also assay potato aphids should they be collected but anticipate low levels of abundance. Obj. 2) We will survey stands of non-crop plants, including matrimony vine and nightshades, and collect winged green peach and potato aphids in the Columbia Basin and south-central Idaho. Both types of plant are important agricultural weeds and perennial host plants of green peach and potato aphids3. Although hairy nightshade is suspected to be an important source of PVY5 and PLRV4, it is unknown whether naturally occurring matrimony vine populations can host PVY or PLRV. Surveys will be conducted on at least three timepoints May–September. Leaf tissue will also be collected and assayed for PLRV and PVY infection. We will process up to 150 aphid specimens for gut contents analysis as described in Obj. 1, pooling them by species if >150 are collected. This objective would complement Obj. 1 in demonstrating whether aphids are moving between these potentially important reservoir plants and potato fields, and how prevalent potato virus infections currently are within naturally occurring stands.