Peach-potato aphids have been found in 2 samplesfrom Angus and Perthshire during the last week.
No Potato aphids were found during the last week.
Black-bean aphids (a good vector of PVA) were found in 2 samples from Angus and Perthshireduring the last week.
Angus and Perthshire: Virus pressure was moderate but lower than the 10 year average. Peach potato aphids were found in both samples. No potato aphids were found. Other potato virus vectors found (all in much lower numbers than their respective 10 year averages): black-bean aphid, bird cherry-oat aphid, currant-sowthistle aphid, grain aphid
Trapping has ended in all but a couple of sites in Angus and Perthshire so this will be the last weekly summary for aphid monitoring in seed potatoes for 2016. Thank you very much to all of you who have taken part in this monitoring scheme this year. It wouldn't work without you all sending in samples each week and providing location information. We hope you will all take part again next year. We would be very grateful for any feedback on the monitoring scheme and the process of taking part. We would also welcome any suggestions for improvements. Best wishes,The Fera Insect Monitoring Team
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.