Summary for 2026:
- Inspection of Scottish seed potato crops over the past few years have revealed an increasing incidence of both PVY and PLRV - the two predominant aphid-borne viruses affecting potato crops in Scotland.
- Whilst Scottish seed potato health remains high and aphid-driven vector pressure remains relatively low when compared to other regions, a series of warmer winters has led to earlier and more abundant aphid numbers than usual which may have contributed to this increase in virus level.
- The temperatures over winter 2025-26 have been warmer than average at Edinburgh and close to average at Dundee, with predictions indicating that first flights of peach-potato aphid (Myzus persicae) would be two (2) weeks early at Edinburgh and around average at Dundee.
- The spring weather during 2026 was mild, wet and unsettled therefore aphid activity starting close to average for all important vector species - the exception being the grain aphid (Sitobion avenae) with the first flight for that species recorded three (3) weeks earlier than predicted.
- Going into the 2026 season, virus inoculum levels for both PVY and PLRV are higher than usual, so effective management of the source of inoculum should be a priority. Best practice aphid control for the management of PLRV and PVY can differ, and it will be important to consider both in 2026.
- A balanced approach to the management of both leaf roll and non-persistent viruses and their vectors with increased vigilance of the timing and number of aphids in your area is recommended for the 2026 summer.
Key Points:
-
Virus inoculum levels (both PLRV and PVY) were higher than usual in 2025.
-
Important aphid vector species started flying around their predicted dates - apart from the grain aphid (Sitobion avenae) which arrived three weeks early.
-
Active virus management (for both PLRV and PVY) advised for 2026
-
Increased aphid vigilance using traps and visual inspection of crops recommended
SASA