Summary information for 07-07-2017 through to 13-07-2017

Sample data for 07-07-2017 through to 13-07-2017

Region Samples Mean PVY Index per Sample Mean Colonising Aphids per Sample Mean Aphids per Sample Total aphid species
North Scotland 13 0.87 0.69 3.31 15
Grampian 16 7.19 7.19 9.94 22
Angus & Perthshire 12 1.39 1.58 3.50 14
Borders 6 0.45 0.33 1.83 6
Northern England 13 6.18 3.08 42.69 20
Midlands 5 28.38 22.60 204.40 18
East Anglia 8 3.54 1.00 26.63 20
South-West 8 1.72 0.63 9.50 15
TOTAL 81 5.06 3.84 26.19 36

Sample data for 2017

Region Samples Mean PVY Index per Sample Mean Colonising Aphids per Sample Mean Aphids per Sample Total aphid species
North Scotland 69 9.28 9.49 25.81 44
Grampian 81 4.78 5.33 10.30 47
Angus & Perthshire 59 4.81 4.85 7.42 39
Borders 33 3.19 3.27 6.97 30
Northern England 98 55.54 46.00 89.00 56
Midlands 49 51.81 39.45 124.37 59
East Anglia 117 7.57 5.78 20.74 60
South-West 76 24.65 20.11 57.51 56
TOTAL 582 20.89 17.40 42.78 94

View a regional breakdown of the sites with the greatest PVY index

Summary information as of 13-07-2017

  • North of Scotland (12 samples), Angus & Perthshire (9 samples), Borders (6 samples), South West (6 samples) - Low Risk
  • Grampian (16 samples), Northern England (10 samples), East Anglia (7 samples)  - Moderate Risk
  • Midlands (5 samples) - High Risk

    • Virus pressure was higher than the average for the last 13 years in: North Scotland, Grampian and the Midlands. Virus pressure in all other regions has dropped back to lower than average for the time of year.
    • Peach-potato aphids have been found in samples from all regions from which samples were received in the last week. Higher numbers than the average for the time of year have been found in North Scotland and Angus and Perthshire.
    • Potato aphids have been found in low numbers in samples from all regions from which samples were submitted over the last week except the Borders.
    • Black-bean aphids (a good vector of PVA) were found in samples from all regions over the last week, except the North of Scotland and the Borders. Numbers have dropped back to below average for the time of year in some regions.
    • Very high numbers of cabbage aphids have been recorded in samples from the Midlands and higher numbers than average in the North of Scotland.
    • 577 samples have been received so far this year.

    • North of Scotland: Virus pressure was low but still 30% higher than the average for the time of year due to an increase in peach-potato aphid numbers. Peach-potato aphids were found at 4 sites and the average number per trap was 25% higher than normal for the time of year. Potato aphids were found at 1 site. Other potato virus vectors found: cabbage aphid (30% higher numbers than average for previous years), willow-carrot aphid (200% higher numbers than average for previous years).
    • Grampian: Virus pressure was moderate and peaked again at 4.5 times higher than average for the time of year due to an increase in numbers of peach-potato aphids. Peach-potato aphids were found at 9 sites. Potato aphids were found at 5 sites. Other potato virus vectors found: bird-cherry oat aphid, black-bean aphid, grain aphid, pea aphid, rose-grain aphid, willow-carrot aphid.
    • Angus and Perthshire: Virus pressure was low and fell to 35% of the average for the time of year. However, peach-potato aphid numbers were still slightly elevated. Peach potato aphids were found at 3 sites in numbers 10% higher than average. Potato aphids were found at 1 site. Other potato virus vectors found: black-bean aphid (numbers decreased to 20% of average).
    • Borders: Virus pressure was low and fell again to 30% of the average for the time of year. Peach-potato aphids were found at 2 sites. No potato aphids were found. Other potato virus vectors found: leaf-curling plum aphid, willow-carrot aphid.
    • Northern England: Virus pressure was moderate and fell again to 70% of the average for the time of year. Peach-potato aphids were found at all 10 sites in numbers 50% lower than the average for previous years. Potato aphids were found at 1 site. Other potato virus vectors found: black-bean aphid, cabbage aphid, grain aphid, rose-grain aphid, pea aphid, willow-carrot aphid (numbers increased to 3 x higher than average).
    • Midlands: Virus pressure was very high but dropped back to 35% higher than the average for the last 13 years. Peach-potato aphids were found at all 5 sites. Potato aphids were found at 2 sites. Other potato virus vectors found: black-bean aphid (still quite a few about but numbers dropped back to average), bird cherry-oat aphid, cabbage aphid (numbers very high and 16 x higher than average for the time of year), currant-sowthistle aphid, grain aphid, leaf-curling plum aphid, rose-grain aphid, willow-carrot aphid.
    • East Anglia: Virus pressure was moderate and only 20% of the average for the last 13 years. Peach-potato aphids were found at 3 sites. Potato aphids were found at 1 site. Other potato virus vectors found: bird cherry-oat aphid, black-bean aphid, cabbage aphid, grain aphid (numbers are average for the time of year but have increased x 2 since last week), leaf-curling plum aphid, pea aphid, willow-carrot aphid (numbers 50% higher than normal and another small peak).
    • South West: Virus pressure was low and fell to only 40% of the average for the last 13 years. Peach-potato aphids were found at 3 sites. Potato aphids were found at 1 site. Other potato virus vectors found: bird cherry-oat aphid (numbers 2 x higher than average), black-bean aphid, currant-sowthistle aphid, grain aphid, willow-carrot aphid. Numbers of both black-bean aphid and willow-carrot aphid dropped back to below average for the time of year after a peak last week.

    • Virus pressure has fallen across some regions in the last week. However it was still high or moderate across all regions in England except the South West and for Grampian in Scotland. Virus pressure was particularly high for the Midlands.
    • The black-bean aphid (Aphis fabae) has been found to transmit PVA so if you are growing PVA susceptible varieties (Desiree, King Edward, Maris Peer, Marfona etc) you may wish to take this into account. This species was found in numbers higher than the average or below average numbers for the time of year in all regions except Grampian and the Borders, where none were found.
    • Cereal aphids: Grain aphids have been found in samples from all English regions and Grampian in Scotland with numbers increasing in East Anglia; Rose-grain aphids have been found in samples from Grampian in Scotland and all English regions in the last week; Bird cherry-oat aphids have been found in in samples from Grampian in Scotland and all English regions except Northern England in the last week with numbers found in the South West 2 x higher than the average for the time of year.

      Along with the results from your aphid trap you need to take into account the following factors when considering the risk of virus spread.