Northern England (4 samples), East Anglia (3 samples) - Moderate Risk
North Scotland (4 samples), South West (1 sample) - Low Risk
North of Scotland: Virus pressure was Low, although 1 Peach-Potato aphid was found.
Grampian: No samples.
Angus and Perthshire: No samples.
Borders: No samples.
Northern England: Virus pressure was Moderate. Peach-Potato aphids found at four sites; one Potato aphid was found. Other potato virus vectors found: Currant-Sowthistle aphid, Leaf-Curling Plum aphid, Willow-Carrot aphid (2x the average), Black-Bean aphid, Cabbage aphid, Shallot aphid, Pea aphid.
Midlands: Virus pressure was High. 37Peach-Potato aphids (2x the average) found across two sites; six Potato aphids were found across both sites. Other potato virus vectors found: Currant-Sowthistle aphid, Leaf-Curling Plum aphid, Willow-Carrot aphid, Black-Bean aphid (2x the average), Cabbage aphid (3x the average), Pea aphid.
East Anglia: Virus pressure was Moderate. 6 Peach-Potato aphids werefound at one site. No Potato aphids were found. Other potato virus vectors found: Shallot aphid, Black-Bean aphid.
South-West: Virus pressure was Low. No Peach-Potato aphids, Potato aphids or other virus vectorswere found.
22 samples have been received this week, from North Scotland, Northern England, Midlands, East Anglia and East Anglia.
Peach-Potato aphid has been found in samples from North Scotland, Northern England, Midlands and East Anglia so far this year. This is approximately three weeks earlier than last year.
Potato aphids have been found from Northern England, Midlands and East Anglia this week.
Black-Beanaphids were present in Northern England, Midlands and East Anglia this week.
If you have not yet started trapping please note that traps should go out 2 weeks before emergence.
If you have started trapping, please ensure that you have sent us the correct grid reference.
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 high numbers from East Anglia this week.
Aphids are becoming more visible with the increase in temperatures, and Peach-Potatoaphids and Potato aphids are already flying. Traps in the South-West and southern half of the country will need to be deployed promptly, if they haven't been already - sites in the North of Scotland are already out, and catching Peach-Potato aphid!
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.