BYDV prevalence and insecticide resistance status in UK cereal aphids

AHDB supports work to improve Barley yellow dwarf virus (BYDV) management through the adoption of integrated pest management (IPM).

The activity includes the monitoring of cereal aphid virus vectors and the development of a model that includes the prediction of the percentage of virus-carrying (viruliferous) aphids across the UK.

This model underpins a new AHDB BYDV tool, which will be released in August 2026.

Specifically, this project provides a regular snapshot of the proportion of virus-carrying cereal aphids, which is a critical data source in the new BYDV tool.

About BYDV

BYDV is a complex of viruses made up of variants/isolates, with some transmitted by more than one aphid species.

For example:

Luteovirus (genus)

• BYDV-PAV is spread by several aphids, including bird cherry-oat aphids and grain aphids
• BYDV-MAV is spread by grain aphids 

Polerovirus (genus)

• CYDV-RPV (formerly BYDV-RPV) is mainly spread by bird cherry-oat aphids

CYDV = Cereal yellow dwarf virus.

Although bird cherry-oat aphid, rose-grain aphid and grain aphid all transmit virus to cereals, ADAS work (which concluded in 2023) confirmed that the former aphid is by far the most significant virus vector across the UK.

BYDV monitoring

This project issues regular (typically weekly) virus reports during the main aphid-flight period (mainly during the autumn).

Typically, the reports are based on laboratory (PCR) test results for BYDV and CYDV from 96 aphid samples (including 4 control samples).

Because a relatively high number fly in the autumn, most of the data is collected from bird cherry-oat aphid samples.

The aphid samples are collected from four suction traps:

• North: York (Y)
• West: Hereford (H)
• East:  Broom’s Barn (BB)
• South West: Starcross (SX)

Virus monitoring has been conducted at the same sites since 2019 (originally as part of a BYDV management research project).

The longer-term resource improves understanding of how virus levels fluctuate on a seasonal and regional basis.

Results show that most aphids do not carry BYDV. For example, average results from autumns 2021, 2022, 2023 and 2024 showed that the proportion of viruliferous aphids did not exceed 30% (although, some weekly results did exceed this figure).

Autumn 2025 saw the highest proportions, when about 35% of the bird cherry-oat aphids tested were deemed viruliferous.

This project also provides information on the proportion of grain aphid samples with moderate resistance to pyrethroids, as conferred by the kdr mutation.

As grain aphid flies in relatively low numbers in the autumn, summer samples of this species are sometimes used in both the virus and resistance tests.

The AHDB aphid monitoring page provides the latest in-season virus testing results.

An overview of the monitoring data for each season can be downloaded on this project page.

*Note: A new goods and services contract is issued each year following an annual request for quotes. The total project value shows the cumulative cost of the work since 2022.

Providing answers to your questions

This research project was funded via a levy-payer-led commissioning process.