Over the past five years Forest Research, in collaboration with Rothamsted Research, has conducted a systematic survey to model the distribution of acute oak decline (AOD) in England and Wales. The results show that the condition currently affects several thousand oak trees, mostly across East Anglia, the Midlands and southern England.

The complex nature of the condition means it is often associated with other pathogens, as well as insect defoliators and the research has not yet concluded whether AOD kills trees or not. A large proportion of the infected trees monitored have entered remission suggesting some level of host resistance. We do not have information at the landscape level on the number of oak with AOD symptoms that die every year.

Since 2013, Defra has invested £1.1 million in research to understand the causes, distribution and scale of AOD in the UK. This includes work to investigate the bacterial species associated with the condition and to understand whether the Agrilus biguttatus beetle plays a role in the dispersal of these bacterial species. Early findings from this research are still inconclusive. There is currently no firm evidence of transmission by the beetle.

Earlier this year, Defra in collaboration with the Research Councils, Scottish Government and the Forestry Commission launched a further £2 million call for research proposals on ‘oak health’ and Phytophthora. The successful bids from this call are due to be announced shortly.

Local authorities have a power under section 4 of the Prevention of Damage by Pests Act 1949 to require owners of premises infested by mice or rats to eradicate the problem and failure to do so is a criminal offence. Infestation by such pests is also a hazard under the housing, health and safety rating system in Part 1 of the Housing Act 2004. Where the infestation is a category 1 hazard the local authority must require the landlord to take action to eradicate the infestation or it may prohibit the property (or the affected part) from being occupied until the hazard has been eradicated. Through licensing schemes under Parts 2 or 3 of that Act an authority can impose licence conditions relating to privately rented homes that require landlords to take measures to prevent infestation of pests and a failure to do so would be a criminal offence.

Defra has not undertaken any assessment of the trends in numbers of cabbage stem flea beetle in the UK. However, we are aware that the AHDB published an assessment on this area in 2014.

The Department does not hold information to answer this question in full. The information requested is not collated centrally and could only be provided at disproportionate cost.

However, the following information may be useful.

· The UK plant health risk register assesses the likelihood of non-native pests and diseases of plants being introduced or spreading to their full extent and the impact and value at risk. The register is updated monthly and the outputs are all published: https://secure.fera.defra.gov.uk/phiw/riskRegister/

· In 2010, a Defra funded study by CABI estimated the cost of yield losses caused by non-native plant diseases at around £282m across GB. A sector breakdown shows the majority of costs are incurred in the grain, commercial vegetable and potato sectors: www.nonnativespecies.org/downloadDocument.cfm?id=487

· A 2010 report by the Animal and Plant Health Agency looked at the costs of ‘conflicts’ between human and wildlife interests, including pests. The estimated £500m annual cost of these conflicts and mitigation actions includes UK agriculture.

· A 2003 Defra study assessed the costs to GB agriculture of 35 endemic livestock diseases. This study has not been updated: http://randd.defra.gov.uk/Document.aspx?Document=ZZ0102_1215_FRP.doc

· Tackling bovine TB costs English taxpayers in the region of £100m per year with additional costs to farmers estimated to run to tens of millions of pounds each year.