The UK aphid monitoring network

Find out about the national network of aphid suction traps and yellow water traps. Delivering regional information on aphid species and numbers (and BYDV), these monitoring resources can guide insecticide treatment decisions.

The suction-trap network focuses on aphid species of importance to cereals and oilseeds crops. It is managed by Rothamsted Insect Survey (RIS) and funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

The 12.2m tall traps suck in air continuously and are emptied daily during the ‘aphid season’. Each trap represents aphid-flight activity over a radius of around 80 km. Aphid species are then identified and counted at Rothamsted Research and SASA (Gogarbank suction trap).

Aphid counts are presented across a ‘Bulletin Week’ (which runs from Monday to Sunday).

In 2020, RIS introduced a free text messaging service to inform cereal growers about the number of aphid vectors in their area. In 2021, this service replaced the PDF/email service called Aphid News.

Fera manages a network of yellow water traps. Compared to the suction trap network, these traps provide more localised (and more recent) information on which aphids are flying close to seed potato crops. Funding from AHDB Potatoes supported this service until statutory levy collection for this sector ceased (2004–21).

We provide a regular snapshot of the proportion of virus-carrying cereal aphids (bird cherry-oat and grain aphids).

Mainly issued during the autumn, the results are based on (BYDV/CYDV) tests of a small number of aphid samples collected from four suction traps (see map). The work screens up to 96 aphid samples each week.

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

The longer-term resource is building a picture 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 and 2023 showed that the proportion of viruliferous aphids did not exceed 30% (although, some weekly results did exceed this figure).

The results also show over-season trends. For example, virus levels tend to be highest at sites in regions with more permanent grassland (which acts as a reservoir for aphids and BYDV).

An AHDB research project that concluded in 2023 found that suction trap data on the percentage of aphids carrying the virus was reliable over a greater area than previously thought, with accuracy good up to 40 km away.

BYDV is a unusual because it is a complex of viruses made up of variants/isolates, with some transmitted by more than one aphid species. For example:

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

The BYDV complex also features the closely related Cereal yellow dwarf virus (CYDV).

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

• York (Y)
• Hereford (H)
• Broom’s Barn (BB)
• Starcross (SX)

6 December 2024

The final update corresponds to the Rothamsted Research Insect Survey 2024 Bulletins 33 and 34  (11 to 24 November 2024).

80 aphids were tested in the final period:

• 80 bird cherry-oat aphids (17 positive)
• 0 grain aphids (0 positive)

2024 overview

• Overall, 1,048 aphids were tested in autumn 2024, with about a fifth of aphids testing positive for virus
• The final proportions with virus (both aphids combined) at the specific suction trap sites were: York (24%), Hereford (23%), Starcross (18%) and Broom's Barn (17%)
• As usual, far more bird cherry-oat aphids were trapped and tested (960), with 20% testing positive for virus (ranging from 24% to 16%)
• Relatively few grain aphids were trapped and tested (88), with 26% testing positive for virus (ranging from 38% to 15%)
• Most of the grain aphids were tested during the early autumn
• BYDV was far more commonly detected (82%) than CYDV (18%)

A note on accumulated data

Accumulated data may include results from back-tests on aphids caught in earlier bulletin weeks. As a result, the accumulated data may be higher than expected (based on the latest weekly data).

Suction trap aphid data and weather data can be used to forecast the start of aphid flights. Although there is considerable uncertainty associated with actual first flight dates at specific sites, the forecasts provide an indication of how early or late flights will take place, compared with an ‘average’ season. It is important to note that some aphids overwinter in crops and are likely to be present before aphid flights commence.