Aphid Predictions

Early season aphid activity in 2026

  • SASA predicts summer peach-potato aphid (Myzus persicae) activity using mean winter temperatures from December to February; colder winters reduce survival and delay population build-up the following spring.
  • Winter 2025-26 was warmer than average at Edinburgh and close to average at Dundee.

  • Predicted first flights of peach-potato aphid for 2026 are: 27th May at Edinburgh and 11th June at Dundee.
  • Average first catch dates are 12th June at Edinburgh and 11th June at Dundee.
  • Predicted peach-potato aphid numbers by 31st July are 30 at Edinburgh and 19 at Dundee.

  • If spring 2026 are normal, Myzus persicae activity is expected two (2) weeks earlier than average in southern Scotland and close to average in the north.

  • Although fewer vectors are expected in 2026, PLRV inoculum remained above average in 2025 so leaf roll transmission risk remains high in 2026. Therefore growers should stay vigilant and maintain active virus management during the growing season.

  • The predictions for other aphid vector species are provided by Rothamsted Research (Aphid Forecast | Insect Survey) and are based on mean temperatures over January and February 2026 (Table 1).
  • First flights for the potato aphid (Macrosiphum euphorbiae), rose-grain aphid (Metopolophium dirhodum) and the grain aphid (Sitobion avenae) are expected to be around average, but populations may still threaten the virus health of seed crops.

Table 1 – First flight predictions for 2026

  2026 Prediction 75% Confidence Limits 2025 Obs'n 2026 Obs'n
Edinburgh
Myzus persicae 29 May 8 May – 19 June 20 April 01 June
Macrosiphum euphorbiae 15 May 24 April – 5 June 30 April 18 May
Metopolophium dirhodum 17 May 22 April – 10 June w/b 17 March 18 May
Sitobion avenae 22 May 2 May – 11 June 5 May 30 April
Dundee
Myzus persicae 11 June 16 May – 7 July 20 May 01 June
Macrosiphum euphorbiae 23 May 30 April – 16 June 6 May 31 May
Metopolophium dirhodum 27 May 3 May – 20 June 21 April 21 May
Sitobion avenae 29 May 11 May – 17 June 21 May 29 May

First flights 2025

  • Warm conditions during April and May 2025 likely brought aphid migration forward by 3-4 weeks.
  • Winter based models do not account for spring anomalies; growers should remain vigilant in unusually warm springs.
  • In 2025, first peach-potato aphid (Myzus persicae) catches were 20 April at Edinburgh and 20 May at Dundee.