Afidopyropen as a potential tool for Potato leafroll virus management in post-neonicotinoid potato production

Potato leafroll virus (PLRV) has been well managed by neonicotinoids since their widespread adoption in the United States, becoming virtually absent from seed and production fields in the Northwest. However, with increasing interest in discontinuing neonicotinoid usage, there is concern that PLRV could enjoy a resurgence in the absence of effective alternative chemistries. We tested the effects of afidopyropen, an insecticide with novel mode of action, on PLRV transmission and the feeding/probing behavior of its primary vector, the green peach aphid (Myzus persicae [Sulzer]). Afidopyropen foliar sprays decreased PLRV transmission by individual green peach aphids relative to water controls: PLRV acquisition from treated potato plants and subsequent transmission was reduced by 89%, and PLRV inoculation by viruliferous aphids to treated potato plants was reduced by 35%. Although electropenetrograph analyses following 4-h recordings of individual aphids on potato plants showed decreases in the total and mean duration of phloem feeding (E) on plants subject to an afidopyropen treatment relative to water, these only trended toward significance. Taken together, these results suggest treatment with afidopyropen can decrease PLRV transmission in potatoes, but that significant changes in feeding/probing might not occur quickly post-exposure. Overall, while the reductions in transmission were not as dramatic as have been observed following neonicotinoid treatments, afidopyropen may be a useful alternative and should be evaluated in field experiments.