North Scotland (9 samples), Midlands (6 samples), East Anglia (16 samples) - Moderate Risk
Grampian (14 samples), Angus and Perthshire (2 samples), Borders (4 samples), South West (5 samples) - Low Risk
70 samples have been received this week, from every region.
361 samples have been received so far this year.
Peach-Potato aphids were found from every region except Angus and Perthshire and the Borders.
Potato aphids were found from every region except Angus and Perthshire, Borders and the South West.
Grain aphids have been found from Grampian and East Anglia this week.
Rose-Grain aphids have been found from Northern England to East Anglia
Black-Bean aphids were present in samples from North Scotland, Angus and Perthshire, Midlands, East Anglia and South West this week. This is a good vector of PVA.
Pea aphids have again been found in Northern England, East Anglia and the South-West.
Glasshouse and Potato aphid, another potato colonising species, has been found again this week in Grampian and Borders.
Willow-Carrot aphid numbers have dropped in all regions.
North of Scotland: Virus pressure Moderate. Peach-Potato aphids at 5 sites, and Potatoaphids at 3 sites. Other potato virus vectors found: Leaf-Curling Plum (nearly double the average, but falling), Willow-Carrot, Black-Bean aphid.
Grampian: Virus pressure Low. Peach-Potato aphid at 2 sites; Potatoaphidsat 1 site. Other potato virus vectors found: Leaf-Curling Plum, Willow-Carrot, Grain, Currant-Sowthistle, Glasshouse and Potato aphid.
Angus and Perthshire: Virus pressure was Low. No Peach-Potato aphid or Potato aphids. Other potato virus vectors found: Black-Bean, Willow-Carrot aphid.
Borders: Virus pressure was Low. No Peach-Potato aphid or Potato aphids. Other potato virus vectors found: Glasshouse and Potato, Currant-Sowthistle aphid.
Northern England: Virus pressure remained High. Peach-Potato aphids at 12 sites; Potato aphids at 2 sites. Other potato virus vectors found: Currant-Sowthistle, Leaf-Curling Plum, Willow-Carrot, Pea, Rose-Grain aphid.
Midlands: Virus pressure dropped to Moderate. Peach-Potato aphids at 5 sites; Potato aphids at 2 sites. Other potato virus vectors found: Currant-Sowthistle, Leaf-Curling Plum, Willow-Carrot, Black-Bean, Cabbage, Shallot and Rose-Grain aphid.
East Anglia Virus pressure dropped to Moderate. Peach-Potato aphids at 13 sites. Potato aphids at 5 sites. Other potato virus vectors found: Black-Bean, Cabbage, Leaf-Curling Plum, Pea, Rose-Grain, Willow-Carrot, Shallot, Currant-Sowthistle and Grain aphid.
South-West: Virus pressure dropped to Low. Peach-Potato aphids at 2 sites; no Potato aphids. Other virus vectors found: Black-Bean (higher than average), Leaf-Curling Plum, Willow-Carrot and Pea aphid.
A few crops have only just been planted, but most are in so please remember that traps should go out 2 weeks before emergence.
If you have started trapping, please ensure that you have sent us the full correct grid reference, and field name.
Without the correct grid reference other levy-payers don’t get the full benefit of the scheme. Any pots that can’t easily be identified will be left until last, which delays the results being sent out to you.
Along with the results from your aphid trap you need to take into account the following
factors when considering the risk of virus spread.
Mature plant resistance. Crops are generally at their most vulnerable
within the first four weeks from emergence. After this time 'Mature Plant Resistance'
builds up which makes it more difficult to transmit virus within the crop. The crop is
again more vulnerable to virus spread if there is regrowth after dessication.
Cultivar resistance. Different varieties of seed will have different
inherent natural resistance to PVY. Using a more resistant cultivar will reduce the
risk of virus transmission.
Volunteers and seed quality. In most situations it is unlikely that
aphids will bring PVY into your crop (see next note). The greatest risk is from aphids
spreading what little virus may already be present. This can come from two possible
sources. Volunteers from previous potato crops and low levels of virus in the seed
Surrounding crops. The risk of aphids spreading PVY to your crop
from elsewhere is increased when ware crops are grown close to your seed. This is
because there will be greater numbers of aphids and ware crops generally have a
higher incidence of virus present.