Crop Inspectors

Aphid Predictions

Early season aphid activity in 2019

Virus Epidemiology

An estimate of the likelihood that aphids will transmit non-persistent potato viruses (e.g. PVY) in the field can be made using the data collected by the aphid suction traps. This estimate, the aphid vector pressure, is calculated by summing the total catch of each aphid species, after multiplication by a factor estimating the efficiency of that species as a vector of PVY. Details of the vector efficiencies used in these calculations are available via the AHDB (Potatoes) Aphid Monitoring webpages.

Summary & Outlook

Inspection of the 2018 Scottish seed potato crop revealed an incidence of crops containing virus affected plants of 9.4% of the total area entered for classification (up from 4.8% in 2017). 

Potato Aphid

The Potato aphid Macrosiphum euphorbiae is often the most numerous of the five or six species of aphids that regularly colonize potato crops in Scotland. It is also a potential aphid vector of non-persistent potato viruses (e.g. PVY, PVA).

Cereal Aphids

From midsummer onwards, the catches of cereal aphids in the suction traps usually dominate the Scottish aphid bulletin and significantly affect the index that is used to estimate the vector pressure for aphid-transmitted potato viruses. Three species, the Rose-Grain aphid (Metopolophium dirhodum), the Grain aphid (Sitobion avenae) and the Bird Cherry-Oat aphid (Rhopalosiphum padi), are known to be vectors of non-persistently transmitted potato viruses (e.g.

Aphid Monitoring of Seed Potato Crops

Aphid monitoring, which was introduced into the SPCS in 1992 to encourage growers to control aphids developing on their crops, has proved effective at encouraging the management of the potato colonising aphids that transmit leaf roll.  It has not proved as successful in assisting with the control of the non-colonising aphids that transmit non-persistent viruses.  Although leaf roll levels increased during 2018 and higher than average activity of M.


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