Corporate report

Advisory Committee on Releases to the Environment (ACRE) annual report 2021

Published 25 March 2022

Foreword by the Chair, Professor Jim Dunwell

This is the twenty-eighth annual report of the Advisory Committee on Releases to the Environment (ACRE). The report highlights the work of the Committee during the year.

Find out more information about ACRE’s work on GOV.UK

ACRE is sponsored by the Department for Environment, Food and Rural Affairs (Defra) and is an advisory non-departmental public body. ACRE’s primary function is to provide statutory advice to the UK government, and the Devolved Administrations of Scotland, Wales and Northern Ireland on the potential risks to human health and the environment from the release, and marketing, of genetically modified organisms (GMOs). ACRE also advises on the release of certain non-GM species that are proposed for use as biological control agents which are not native to Great Britain.

During 2021 ACRE assessed 2 applications for plant trials for research purposes (which included gene-edited and genetically modified wheat lines) and is further considering a third application for gene-edited and genetically modified barley.

ACRE also reviewed the risk assessments for 2 GMO clinical trials. One of these was for a whooping cough vaccine and the other a COVID-19 vaccine which was reviewed outside of the statutory GMO legislation since it qualified for a derogation under retained EU law.

Further, ACRE has provided detailed advice to the government on the scientific aspects of their consultation on the regulation of organisms resulting from genetic technologies. ACRE has continued to work with Defra as it develops its policy in this area.

Professor David Hopkins’ tenure as a member of ACRE ended in April. His expertise in soil science, and the decomposition of residues from plants with genetic modifications was particularly valuable for the assessment of the environmental impacts of GM crops. Additionally, his input to the Committee’s wider work areas, including its post-market environmental monitoring subgroup, was very much appreciated.

As Chair, I would additionally like to express my thanks to current members of ACRE for their continuing support, and dedication. I should also like to thank the assessors, and the ACRE Secretariat for their efforts in supporting the work of the Committee.

Openness and transparency are important principles for the Committee to adhere to, and I am keen that ACRE continues to do so by publishing its advice.

Main activities

Meetings

ACRE discussed and formulated its response to the government consultation on the regulation of genetic technologies and conducted specific areas of business via correspondence as necessary.

As part of ACRE’s commitment to openness and transparency, [advice the Committee provides is published on the ACRE pages of GOV.UK.]((https://www.gov.uk/government/organisations/advisory-committee-on-releases-to-the-environment)

Casework

Applications for GM releases for research purposes

ACRE has assessed 2 applications for GM wheat research trials and is further considering a third application for GM barley. Assessments were undertaken in accordance with retained EU legislative requirements. The 2 wheat trials are investigating:

1. Reduced levels of asparagine synthetase in the grain
2. Increased levels of bioavailable iron in the grain under field conditions

The barley application is investigating the impact of editing and modifying barley genes involved in the symbiotic interaction between barley roots and arbuscular mycorrhizal fungi in the soil.

ACRE has also assessed 2 GMO clinical research trials in accordance with retained EU legislative requirements. One of the clinical trials was for a vaccine against whooping cough and the other for a vaccine against COVID-19. The latter assessment was done outside of the statutory GMO legislation since it qualified for a derogation under retained EU law. ACRE’s advice on this is not available for publication at the time of writing.

ACRE has also advised Defra on an updated version of application 20/R48/01 (vaccine against Salmonella Paratyphi A). This was to enable the trial to begin at a later date than indicated in the consent because the COVID-19 pandemic had delayed the applicant’s preparations for the trial.

The applications, ACRE’s advice and the outcomes are available on the GOV.UK website:

• Genetically Modified Organisms: Rothamsted Research (21/R08/01)

• Genetically Modified Organisms: John Innes Centre (21/R52/01)

• Genetically Modified Organisms: ILiAD Biotechnologies, LLC (21/R53/01)

• Genetically Modified Organisms: Oxford Vaccine Group (20/R48/01a)

• Genetically Modified Organisms: Cambridge University Crop Science Centre (21/R54/01)

Other advisory duties

The Animal and Plant Health Agency (APHA), an Agency of Defra, had reviewed their policy on restricting the release of augmentative arthropod non-native biological control agents outside of glasshouses, with a view to remove this restriction. However, because this would represent a significant change in policy APHA were keen to seek the view of ACRE. As these species are not native to Great Britain. Licenses as non-native biological control agents under the Wildlife and Countryside Act 1981 are required in order to release them into the environment.

ACRE’s view was that they were broadly content with the recommendation to remove this restriction, such that these non-native biological control agents could be licenced for release under all protected conditions. However, ACRE were concerned as to whether or not the current restrictions were disproportionate because there was a lack of assessment of the opportunity presented by removal of these restrictions.

ACRE’s advice is included in the relevant Annex to this report.

ACRE has provided detailed advice to Defra concerning scientific aspects of its consultation on the regulation of organisms resulting from genetic technologies.

The advice is assisting Defra in its consideration of the issues raised by the public consultation, including the scientific aspects of certain safety considerations. ACRE concluded that gene edited organisms do not pose any greater risk than similar organisms produced through traditional breeding methods and will continue to provide independent expert scientific advice to government as this policy area develops.

Governance and transparency

ACRE is a statutory advisory committee appointed under section 124 of the Environmental Protection Act, 1990. The Committee provides advice to government regarding the release and marketing of GMOs. ACRE works within the legislative framework set out in Part VI of the Environmental Protection Act, and the GMO Deliberate Release Regulations, 2002, which, together, implemented Directive 2001/18/EC (retained EU law).

Below are links to various sources of information relating to the work and membership of ACRE:

• Framework agreement
• Terms of reference
• Members’ biographies and register of their interests

Annex A: ACRE advice about an application to release the non-native parasitoid wasp Torymus sinensis into England

Alien, or non-native species are recognised as the largest threat to biological diversity after that of habitat destruction. The oriental chestnut gall wasp D. kuriphilus is the most damaging insect pest of chestnut species (Castanea spp.) worldwide.

This invasive alien species is currently established in Southern England, and it is a significant pest of sweet chestnut wherein it forms galls. The sweet chestnut tree itself is an introduced species in the UK with significant amenity value; in forming galls the wasp D. kuriphilus can cause significant reduction in both this, and in its value for sale.

In studies during 2019, for example, the gall wasp appeared to significantly impact the growth of coppiced sweet chestnut tress by reducing the area of foliage as a result of smaller and fewer leaves.

Although D. kuriphilus was an accidental introduction to the UK as recently as 2014, as it spreads across South-East England the economic impact due to this is likely to become of greater significance in the future. The only effective management of this pest is by way of a classical biological control agent (BCA), Torymus sinensis (a parasitoid wasp), which is not native to Great Britain.

Under the Wildlife and Countryside Act 1981, it is an offence to release an animal into the wild, which is not ordinarily resident in, and is not a regular visitor to, Great Britain. However, these animals can be released into the wild if they have a non-native biological control licence, which has been approved by Defra.

There are currently 3 classical non-native biological control agents that have been approved for release into the UK:

1. The predatory beetle, Rhizophagus grandis, which is used to control the bark beetle, Dendroctonus micans.
2. The psyllid, Aphalara itadori, which is used to control the invasive Japanese knotweed, Fallopia japonica.
3. The mite, Aculus crassulae, which is used to control Australian swamp stonecrop, Crassula helmsii.

T. sinensis would represent the fourth classical biological control agent release into England if it is approved.

In compiling this application, Fera Science Ltd have completed a risk assessment for T. sinensis, identifying and addressing the risks associated with the intentional release of the wasp into England. ACRE considered this application from the point of view of the following principal areas:

Efficacy and benefits

The release of T. sinensis has occurred in Croatia, France, Hungary, Japan, Portugal, Slovenia, Spain, Turkey and the USA, without ill-effects. It is an extremely successful biocontrol agent for its target (the cynipid D. kuriphilus).

The wasp has proven highly successful in northern Italy, where D. kuriphilus infestation rates have been reduced to almost zero, 9 years after release. Equally in Southern Italy the BCA affected a drastic reduction in D. kuriphilus numbers within only 5 years.

The principal benefits gained from the suppression of D. kuriphilus populations are twofold. Firstly, by lowering the risk of galls reducing foliage area and affecting branch architecture, which is detrimental to the quality of coppice grown for fencing. Secondly, a reduction in the numbers of galls, thereby improving the appearance of sweet chestnut trees; the latter being introduced to the UK due to it having significant amenity value.

ACRE considered that this application therefore highlights one problem for which there appears to be a cost effective solution. That is when placing the chestnut gall former D. kuriphilus in the context of a number of expanding threats to UK broad leaved trees, which include ash dieback, chronic oak dieback, horse chestnut leaf miner, Dutch elm disease among others.

ACRE also noted there is in this case an additional protection against spread of the regulated disease sweet chestnut blight and its causal agent the plant pathogen (Cryphonectria parasitica). This is because the aim of the biocontrol agent is to reduce the incidence of galls and the subsequent holes left by emerging adult D. kuriphilus, and it is these holes that can act as entry points for C. parasitica.

The application included a Cost Benefit Analysis indicating that the release programme provides value for money as the benefits of a recovery in the yield and non-market benefits of sweet chestnut trees outweighs the programme’s outlays by a ratio of 0.59.

Uncertainties

Host specificity

ACRE noted that, contrary to initial reports, T. sinensis is not completely specialised on its target host. Host range studies were not fully completed prior to release in Italy because the target pest was so damaging to the timber industry; post release studies in that country showed it parasitising other gall forming wasps on oak, but the incidence of this was found to be very low (only 0.01% of adults reared from 14,512 non-target galls).

Subsequent to the release in Italy, more complete host range studies were conducted and FERA’s risk assessment takes these into account. There is only one threatened gall forming wasp in the UK and it is not thought that it would be in any danger from release of T. sinensis.

ACRE further noted that said attack rates on non-targets were very low (<1% parasitism) in the context of >50% parasitoid attack of these gall formers in natural communities. The latter levels of host parasitism have been recorded in more than one European study.

ACRE further considered that this rate of non-host parasitism may be a high estimate as the data collection took place when the target host population was crashing and there may have been an excess of parasitoids to targets.

The application reports that host range appears to be expanding; that the reasons for this expansion are not fully understood, and that potentially this impact could be exacerbated in the UK as D. kuriphilus are less abundant when compared to Italy.

To act as a counter to this, the application makes reference to studies, including one in France, wherein T. sinensis underwent an extended diapause (a form of embryonic dormancy) covering 2 years rather than merely overwintering in response to the drastic reduction in D. kuriphilus numbers.

ACRE noted that FERA considered this an adaptive mechanism in their risk assessment, where they described it as a ‘bet-hedging’ strategy; suggesting the expansion of host range to make up for a collapse in the D. kuriphilus population is not so important as that of waiting for its main host’s numbers to recover. This appears to lead to cyclic waves in the respective population of pest and parasite; the latter following the former and so controlling it.

Hybridisation

ACRE noted that T. sinensis has been observed mating with T. beneficus (a native parasitoid) post release in Japan, and this mating has resulted in the displacement of the late spring strain of T. beneficus.

The early spring strain of T. beneficus has also been displaced, but this was likely due to competition from T. sinensis rather than hybridisation. Displacement of native species in the UK is unlikely to happen because there are no native species that rely on D. kuriphilus as their main host.

Experiments in Italy have confirmed high levels of mating specificity and no evidence for potential hybridisation with parasitoid wasps of native European origin; therefore, interbreeding with native Torymus species is unlikely.

Furthermore, there have been no other records of hybridisation by T. sinensis in Europe, and no evidence that it will do so in the UK, despite experimental attempts at such crosses being made. In addition, ACRE also considered what the ill effects of any such hybridisation might be and was satisfied that these were unlikely to be severe.

Other considerations

ACRE agreed with the FERA risk assessment in that it could see no other identifiable threats to the UK environment from the release of this species, and that no negative environmental impacts have been noted in prior releases.

Effect of UK climatic conditions on the establishment potential of T. sinensis

ACRE noted that the risk assessment used Climatic modelling to indicate that the wasp should be able to establish in South-East England where D. kuriphilus occurs.

Factors that may interfere with establishment include:

• the relatively low density of sweet chestnut trees
• a low density of D. kuriphilus galls
• the mortality of T. sinensis in galls overwintering on the ground
• the effect of climate on synchronization between the gall formation and T. sinensis adult emergence
• effects of hyper-parasitism

ACRE agreed with the application that any expansion of host range by T. sinensis is likely to be negatively affected by the different climatic conditions; this is reinforced by studies carried out in France. However, FERA have set out in their application plans for extensive post-release monitoring in order to assess both this and the other areas of uncertainty above, so as to better inform subsequent biocontrol agent releases.

Conclusion and recommendation

ACRE, in reviewing this application, highlighted the uncertainty as to how widely T. sinensis could spread in the UK; potential alternative native species targets, and the effect of climate differences with respect to Italy where these aspects have been well-studied.

However, ACRE noted that FERA’s risk assessment had addressed these points and taken them into account in its proposed post –release monitoring, in order to inform more fully subsequent biological control agent releases.

Therefore, on balance, ACRE was content with the information presented in the risk assessment and its advice was to recommend that a licence to release should be given.