Complete: Combating resistance to aphicides in UK aphid pests

Timescale: 2013 - 2016

Project Lead: Dr Neil Paveley

Project Sponsor: ADAS led collaboration with Rothamsted, AHDB, PGRO and BBRO

Project Summary

Supported by the Chemical Regulation Directorate (CRD), and a consortium of agrochemical companies and levy boards, this project provides research on aphicide resistance management for the UK farming industries and up-to-date information for agronomic and regulatory procedures. This is heightened by the occurrence of control failures with neonicotinoids against M. persicae in southern Europe. The presence of resistant aphids in the UK would have very serious repercussions for neonicotinoid treatments on sugar beet. The project monitors the response of field-collected live samples of M. persicae to a range of novel aphicides and also monitors for established forms of resistance. Vigilance is essential to safeguard the contribution of these compounds to aphid pest management in the UK, as resistant aphids that cannot be controlled will cause crop losses.

Main Objectives

Overall aim

Maintain effective chemical control of economically important pests of arable and horticultural crops.

Objectives

1) Compare the net benefit of different insecticide resistance management strategies for insect pests with contrasting traits (life-cycles, genetics and damage mechanisms).

1.a Develop and test models for insecticide resistance selection and management

1.b Compare the effectiveness of anti-resistance strategies.

1.c Define groups of pests for which similar anti-resistance strategies are most applicable.

2) Develop a method to assess insecticide resistance risk based on objective and measurable criteria.

2.a Construct a data base of previous cases of resistance.

2.b Quantify the effect of pest, insecticide and agronomic system traits on the risk of

resistance.

3) Transfer new knowledge of anti-resistance strategies and risk assessment to end-users.

3.a Translate results into messages and guidance on resistance management for

HGCA, HDC and PCL levy payers, and to underpin regulatory decisions by CRD, in

liaison with IRAG.

3.b Subject findings to peer review and publish in international journals.

Latest Report

Final Report

Outcomes / Key Message For Growers And Industry

Screening of M. persicae samples taken from the field and protected crops in 2016 showed that there continues to be significant resistance (that may compromise control) to a range of newer compounds belonging to different chemical classes. Furthermore, there have been no significant shifts in response to diagnostic doses of these insecticides that are currently effective (un-resisted) in the UK.
Strong pirimicarb resistance and pyrethroid resistance (conferred by MACE and super-kdr target site mechanisms respectively), remain prevalent in the M. persicae samples although there is evidence for a slight fall in their frequency over the past several years which reflects changes in the make-up of the population.
Our findings continue to suggest that at least some aphids in our M. persicae samples collected from protected crops may have come from more genetically-diverse, sexual populations on imported plant material. Obtaining samples from these environments remains very important as they are more likely to harbour aphids with new resistance mechanisms (e.g to neonicotinoids) coming into the UK from abroad.
The baseline work on important pests other than M. persicae continues to add data to the large database and will allow species that are involved in future reports of insecticide control problems to be quickly screened for potential resistance (that has not been seen before).
Three M. euphorbiae samples (collected in England from lettuce and strawberry) were tested in response to reports of control problems. No evidence for insecticide resistance was found in the M. euphoribae samples.