Minutes of the 13th meeting held at Warwick HRI, Wellesbourne, England. Thursday 21st October 2004.
- Bean, Chris United Agri Products (UAP)
- Collier, Rosemary
- Denholm, Ian (Rothamsted, Chair)
- Devine, Greg (Rothamsted)
- Fenton, Brian SCRI
- Foster, Steve (Rothamsted, Secretary)
- Grosjean, Otto (BASF)
- Hingley, Peter (Certis)
- Macnicoll, Alan The Food and Environment Research Agency(FERA)
- Mattock, Sue Pesticides Safety Directorate (PSD)
- McCaffery, Alan (Syngenta)
- Meredith, Richard (Bayer Crop Science)
- Parker, Bill Agricultural Development and Advisory Service (ADAS)
- Powell, Vivian Horticultural Development Council (HDC)
- Solomon, Mike Horticulture Research International (HRI)
- Alan Dewar (Brooms Barn)
- Keith Waters The Food and Environment Research Agency (FERA)
Welcome membership and apologies for absence
Rosemary Collier was welcomed as a new member of Insecticide Resistance Action Group (IRAG.) Alan Dewar (invited guest) and Keith Waters(deputising for Alan McNicoll) were welcomed to the meeting.
Apologies for absence were received from:
- Bean, Chris UAP
- Devine, Greg (Rothamsted Research)
- Grosjean, Otto (BASF)
- Hingley, Peter (Certis)
- Macnicoll, Alan FERA
- Powell, Vivian HDC
Despite being unable to attend recent meetings Mike Solomon and Alan McNicoll are still keen to remain involved with {(IRAG.){}}
Further to the previous meeting it was felt that it would be good to initiate discussions on current and future risks of insecticide resistance for different UK commodity groups. Alan Dewar had been invited to focus on the sugar beet industry.
Minutes of Last Meeting (already distributed)/ Matters Arising
IRAG minutes are available on Insecticide Resistance Action Group: Home.
The minutes of the last meeting (Thursday 25th March, 2004) were agreed.
Feedback from IRAC, Including Brussels Meeting
Alan McCaffery gave a brief overview of what Insecticide Resistance Action Committee (IRAC) has been doing recently. The IRAC website has been completely redesigned by its Coordination Officer, Alan Porter. It now provides links to a range of sites with 57 public pages and a secure site for members. The website has been ranked first by Google for key words such as insecticide resistance and insecticide resistance management. It has been ranked fourth for insecticides. In August 2004 there was an average of 58 users per day.
It is now a priority to develop more education and training material and the first draft for this is due to be completed by February 2005. If any IRAG members have material or links to material available they would be very welcome to contact Alan McCaffery. Brian Fenton enquired about the targets for educational material. Alan McCaffery said that there has been much debate on this. The intention is for a broad range of users from growers in the third world to consultants and academics based at universities. The web-based information will be tiered to allow access to the appropriate level of information required.
E-connection is an electronic newsletter with a large and growing new circulation list around the world. It is intended that the non-refereed IRAC Pesticide Resistance Newsletter should no longer be a vehicle for publishing original and often sub-standard papers. However, brief high quality articles are needed, ideally based on studies published in refereed journals.
IRAC has had a key involvement in, and produced posters for, a number of recent meetings: 22nd ICE, Brisbane, Australia, August 2004; 2nd European Whitefly Symposium, Croatia, October 2004; the Brazilian Congress of Entomology and a meeting on null European and Mediterranean Plant Protection Organisation (EPPO) guidelines held in Italy. It also now has a number of country-based groups with the intension of being less European-focussed. IRAC-Brazil has been very active and IRAC-Asia has just been formed.
In the USA there is a neonicotinoid group developing new guidelines. However, attempts to form an international group remain reliant on encouraging several Japanese companies to get involved. This continues to be a stumbling block.
It is intended that IRAC will produce an updated classification of Modes of Insecticide Action with an emphasis on alternations between compounds that are not subject to cross resistance. This scheme, together with IRAC's suite of standardised techniques for resistance monitoring, is making an important contribution to the implementation of resistance risk guidelines in Europe. IRAC is in the final stages of producing a Vector Resistance Manual and web-based Resistance Forum.
Alan Dewar enquired how IRAC is funded. Alan McCaffery replied by saying that funding comes from subscriptions from chemical companies and allows the employment of Alan Porter as a part-time private Coordination Officer. His work on the website had dramatically improved the image of IRAC.
ID summarised the IRAC meeting held in Brussels where he had suggested links with IRAG. This had stimulated a discussion on certain caveats as IRAG largely has a UK remit and is seen as an independent body while IRAC is still generally perceived as being company-driven with a strong industry viewpoint.
It was suggested that we should hold a joint IRAC/IRAG session at British Crop Protection Council (BCPC) in Glasgow next year. This will be a key item for discussion at the next IRAG meeting.
Action: AMcC to sound out other IRAC members regarding this proposition.
Feedback from CPA
There was nothing to report on this topic.
Regulatory Issues
A discussion took place on the forthcoming loss of triazamate due to its re-registration not being supported in the next review list (a result of a commercial decision by BASF). AD pointed out that it had only been approved in 1996 and enquired what aspects of the review were the EU focussing on and why BASF were not selling possession of triazamate to another company? He felt the loss of this compound would be significant as it was the best aphicide spray available and would be invaluable if imidacloprid efficacy becomes compromised.
Oliver Macdonald has collated PSD's Resistance Risk Assessment Guidelines for insecticides, fungicides and herbicides including comments made at the last IRAG meeting. These are now being circulated to Crop Protection Association (CPA)and are on the PSD website.
The first approval has been issued via the PSD pilot project. This scheme is to encourage the development and approval of non-traditional chemical pesticides, such as 'biologicals' and pheromones, based on reduced fees and reduced data requirements where appropriate. The product, 'Exosect', uses a novel mating-disruption technique aimed at reducing codling moth damage in apple. Males are lured into a dispenser which contains electrostatic powder impregnated with female pheromone. Males become coated in the powder and are unable to locate individual females and also act as false lures to other males. Richard Meredith pointed out that the efficacy of such approaches will be limited.
Ian Denholm summarised initial feedback from the EPPO workshops on resistance risk assessment that he attended in Bologna, Italy, the previous day. It was clear from the workshops that different countries are adopting different approaches to interpreting the EPPO standard (PP 1/213) and that some are at a much more advanced stage of implementation than others. The UK's lead in this respect, and in providing technical guidance to evaluators and applicants, was apparent throughout the workshops. A number of contentious issues remain relating to the extent of baseline sensitivity data required and requested for post-launch monitoring. Oliver Macdonald had represented PSD at the workshop and James Clarke Weed Resistance Action Group (WRAG)) had given a strong account of the activities of Resistance Action Groups (RAGs) in the UK. This concept had been well received and seen as a model that other European countries or groupings of countries might adopt. A copy of Ian Denholm's slides will be circulated to IRAG members with the agreed minutes.
Update on Research
Rosemary Collier described progress on a Defra-funded project aimed at addressing the shortage of actives used against aphids on brassicas and salad crops. This is the end of the first year. Novel actives have been screened (one as a seed treatment, one as a novel granule and the rest as sprays) against clones of Myzus persicae, Nasonovia ribisnigri and Brevicoryne brassicae inoculated onto lettuce or cabbage in field cages (using the best host plant for each aphid species). Their efficacy has varied, with dramatic differences between aphid species although there was no obvious species/crop relationship. In addition, Dave Chandler at Warwick HRI has assessed four products representing three species of entomopathogenic fungus and selected the most effective product for detailed assessments in inoculation experiments in field cages. Later in the project suction-trap data on Brevicoryne brassicae will be looked at by Richard Harrington at Rothamsted Research, in the context of forecasting using a comparable method as that currently employed for Myzus persicae.
Ian Denholm said that a number of Nasonovia ribisnigri samples, taken from areas where resistance risk is high and control appears to have been recently compromised, are due to be assessed in the next few months for their responses to pirimicarb, lambda-cyhalothrin, imidacloprid and pymetrozine. Alan Dewar pointed out that it would be valuable to look at any changes in lifecycle (anholocyclic versus holocyclic reproduction) in Nasonovia ribisnigri samples.
Ian Denholm summarised results from lamda-cyhalothrin bioassays on pollen beetle samples collected from oilseed rape in 2004. This research has been prompted by considerable concerns of resistance of this species in mainland Europe (primarily in France, Germany, Denmark and Sweden) to pyrethroids. In these regions resistance appears to be conferred by detoxification mechanism(s). Rothamsted Research have now developed a new topical bioassay method which has been used to validate baselines for a number of samples. From these data three diagnostic concentrations have been chosen for use on samples collected by ADAS. These have produced no evidence for strong resistance in the UK although a trend was seen towards slightly greater survival (up to 25%) towards the end of the season. Bioassays done next year would establish whether this persists through to next season.
Brian Fenton summarised a (SEERAD)-The Scottish Executive Environment and Rural Affairs Department funded project assessing the factors affecting the prevalence of clones of Myzus persicae in Scotland, particularly those with aphicide resistance, and implications for virus control in seed potatoes. This is being done at SCRI. The research was precipitated by the major problems in controlling Myzus persicae in Scotland in 2001, caused primarily by Modified Acetyl Cholin Esterase (MACE) resistance to pirimicarb, which had a major effect on the seed potato industry. It is hoped that the project will help us understand how changes in the Myzus persicae population can result in resistance flare-ups. It would appear that the English Channel and North Sea are not good physical barriers and many colonisation events can take place from the highly-diverse mainland European populations into the UK, either through migration or movement of aphids on plant material. However, resistant forms appear to be restricted in number with only two UK clones (defined using micro-satellite profiles) carrying MACE, one green and one red in colour. The Scottish red form is the same as that seen in England in 1996 while the Scottish green form appears to have arrived in the UK later.
Mike Solomon and Sue Mattock updated the meeting on recent research on biocontrol agents done at East Malling. In collaboration with Warwick HRI, a virus pathogen aimed at codling moths has been tested. In future, such an agent, along with pheromone disruption products such as the recently approved 'Exosect' (see 5. above), could be incorporated into existing insecticide programmes. This would be on a limited basis however since typically only two insecticide applications are made for codling moth control. A sex pheromone aimed at disrupting the mating of apple-curling midge was found to have high efficacy. A research project aimed at assessing the timing of autumn applications against rosy-apple aphids is also currently running in collaboration with Rothamsted Research and Southampton University. Thiacloprid is used against this pest species which is very difficult to monitor in the spring. It takes only a few individuals to cause damage to the crop. There are a range of Horticultural Development Council (HDC) projects on strawberry aphids grown under tunnels. The resulting changed environment favours Western Flower Thrips which are becoming more common. Some work on habitat manipulation to encourage beneficials is taking place on hops. Alan Dewar asked how imidacloprid was applied to this crop. Richard Meredith replied that this was done using a drench and that most of the hop area was treated. These applications do not appear to work as well as they used to but Richard Meredith felt that there was no associated resistance issue. Most of the hop acreage will move over to dwarf varieties (approximately 2 meters high) in the near future. These will make operations easier and are resistant to hop aphids.
Keith Water's made the meeting aware of work on whiteflies looking at interactions between insecticides, parasitoids and entomopathogenic fungi. Papers are due to be published on the affects of sub-lethal residues on ladybird behaviour.
Resistance issues in sugar beet (interactive session introduced by Alan Dewar)
Alan Dewar presented data describing the changes in chemical usage on sugar beet over recent years. Risk of control failure due to resistance to conventional insecticides has fallen due to the large area (~75%) of sugar beet now being treated with imidacloprid (Gaucho). Poncho-beta (clothianidin plus a pyrethroid aimed at soil pests) is currently used on 3% of seed. There is therefore widespread neonicotinoid use on this crop; a worrying situation because treatment is prophylactic. Temik and carbofuran have been withdrawn, being replaced by oxamyl (Yydate). Gaucho seed treatments are ordered in July, applied between November and January and distributed to growers in March with no real time flexibility in the system. Furthermore, sugar beet is not the only crop treated as oilseed rape and brassicas receive seed treatments. On the former crop Myzus persicae is not controlled after mid-October probably due to the low rate of treatment (about one sixth of that on sugar beet). This is when most Myzus persicae are flying. The biggest risk to the evolution of resistance is probably the ubiquitous use of imidacloprid on containerised ornamentals through treated compost or soil drenches and it is surprising that we have not seen evidence of resistance already.
Alan Dewar and collaborators at Rothamsted Research have done field trials each year at Brooms Barn to assess the efficacy of various compounds, usually applied as seed treatments, for controlling myzus persicae carrying different mechanisms of resistance (esterase, MACE, kdr, coupled with low resistance to imidacloprid). These have shown no evidence that low-level resistance to imidacloprid, known to exist in this pest, compromises Gaucho applied at full or even reduced rates (although separate data gained by Steve Foster at Rothamsted Research suggest reduced soil drenches are compromised on Chinese cabbage). Furthermore, half rate and double rate treatments of imidacloprid on oilseed rate also did not appear to be affected. There was a serious outbreak of virus yellows in the North Yorkshire area this year which was probably a result of the low usage of Gaucho-treated seed in this region. This problem would inevitably quickly become more widespread if imidacloprid efficacy broke down in the future due to the evolution of greater resistance. Steve Foster pointed out that a new SA-Link project was underway to assess the prevalence in the UK of Myzus persicae clones carrying low imidacloprid resistance or greater resistance. This will assess samples taken from a range of crops and regions including glasshouses where selection pressures are probably currently the greatest. At this stage we can be little more than vigilant as there is no precedence in other countries for imidacloprid resistance in any aphid pests. It is hoped that IRAG-UK will have an input on which regions of the country are chosen for aphid sampling, and in reviewing progress generally. Selection pressures by neonicotinoid insecticides are inevitably going to increase in the future so we need new classes of chemistry coupled with good plant hygiene for imported material. One of the worst case scenarios for resistance would appear to be on peach trees in Europe where imidacloprid is used as a spray under the trade-name Confidor.
The possibility that imidacloprid will be registered in the UK for spray applications is unlikely to occur as it would be contrary to good resistance management. Alan Dewar asked if growers not using untreated seed could apply thiacloprid as a spray. It was generally felt that this would not be a good idea. Work on enhancing the efficacy of pymetrozine using adjuvants such as 'Partna' could be beneficial to the sugar beet industry as pymetrozine alone would give poor aphid control. Resistance to imidacloprid has evolved in other pest species including whiteflies and Colorado potato beetles. This appears to be mediated through enhanced detoxification by MFOs. Ian Denholm pointed out that there is preliminary evidence that resistance to imidacloprid in brown planthoppers on rice in Asia is target-site based.
It was agreed that the next commodity to be discussed should be glasshouse crops, and that Jude Bennison (ADAS) would be invited to lead the discussion.
Action: Ian Dewar/Steve Foster to send invitation to Jude.
Pest Resistance Matrix - Where do we Stand?
Apart from a suggestion that pests of stored products should be on a separate sheet to help readers, Bill Parker had received no further comments back on the Resistance Matrix and would therefore put it onto the IRAG website and News Update and ask for further comments. This could be linked through the IRAC website. E-connection could also be used to advertise the Matrix.
Action: Bill Parker to send the latest version of the Resistance Matrix to Sue Mattock.
IRAG Outputs
There had been no actions on this since the last meeting apart from members attending meetings and taking IRAG-UK fliers for distribution. The flier has also been put on the IRAG-UK website.
Action: Ian Denholm and Kevin Gorman at Rothamsted will draft a Factsheet on Trialeurodes vaporarium for comment.
AOB
A short discussion took place on the availability of alternative chemistries to neonicotinoids and pymetrozine for controlling resistance in whiteflies.
Alan McCaffery suggested that a workshop on methodology would be useful.
Sue Mattock and Rose Collier pointed out that the membership details and Factsheet on the IRAG website needed updating. The myzus persicae Guidelines also need updating.
Action: Steve Foster to review the Guidelines and distribute draft updates to IRAG members for approval before placing on IRAG website.
Date/Venue of Next Meeting
The 14th meeting of IRAG is scheduled to take place on 14th April 2005 at Bayer CropScience, Hauxton and will hosted by Richard Meredith. Details will be sent later.
Action: All members of IRAG to advise Steve Foster on availability for that date.
