Skip to main content

Oak Processionary Moth

Volume 727: debated on Wednesday 27 April 2011


Asked by

My Lords, Forest Research has moved from a strategy of eradication to one of containment in the west London outbreak area. Outside this, a protected zone has been declared, within which regular surveys will be conducted to ensure that any new infestations are eradicated.

My Lords, I must declare an interest as a patron of the Friends of Richmond Park. Richmond Park will spend £50,000 or more this year to remove nests of that moth in order that the public can continue to use the park.

The Minister will be aware that the health hazards of the oak processionary moth caterpillar are such that to remove the nests people have to be in full chemical contamination gear, including breathing apparatus. Therefore, he will understand that I am very distressed that the eradication programme has now been set aside. Can he tell us how containment is going to work; and can he give assurances that areas of oak woodland will not have to be closed to the public, as they have been in Holland and Germany, because of the impact of this moth?

My Lords, I am grateful to my noble friend for all she has said. She is quite right in, first, underlining the public health issues and, secondly, underlining the fact that some oak woodland areas might have to be removed from public access, as has happened in other parts of the EU, although we hope that it will not happen here.

The reason we have moved from eradication to containment is based on scientific advice that eradication within the five boroughs in south-west London that the noble Baroness is aware of is not possible. We managed to eradicate the outbreaks in Leeds and Sheffield but we got on to those much earlier. We did not get on to this outbreak, which started in the summer of 2006, early enough and therefore it will be very difficult to get rid of it. However, we are very grateful for all the work being done by Forest Research, Fera and by Kew Gardens, which also has an interest as it is right in the middle of the area.

My Lords, will the Minister confirm that this moth affects other trees as well as oak? In view of the fact that Defra has required the Forestry Commission and Forest Research to reduce their budgets by 25 per cent, with a similar reduction in their staff, is the noble Lord absolutely confident that we have the resources available to tackle this tree-related disease plus the many others that are coming in from overseas at this time?

My Lords, the first point to make is that we do not know that this disease has come from overseas; we do not know where it has come from. Secondly, my advice is that it affects oaks, but I will write to the noble Lord if it affects other trees as well. Thirdly, there is no question of budgetary constraints affecting the fight against this particular menace. I have spoken to the Forestry Commission today and it was perfectly happy to assure me that they had all the resources it needed to fight the problems of the processionary moth. The simple problem is that there are an awful lot of them in a confined area and there are an awful lot of oaks around, and finding all the eggs, larvae and so on is very difficult indeed. Money is not in question.

My Lords, my noble friend in his last supplementary answer said that the Government do not know where this moth originated from. Does he know whether the moth affects oaks in other countries more seriously than it does here?

My Lords, there are bad outbreaks in other countries. My noble friend Lady Kramer referred to the problems in the Netherlands. As I said, we cannot be certain as to how it got into the country. It is as likely as not that it came in from imports via the plant trade, but we simply do not know. We will do what we can to continue the fight, but, as I said, it will be one of containment rather than eradication.

My Lords, the Minister seemed to imply that the moth had not been found because of a lack of surveyance and that it had been in the woods in south London since 2006. Can he assure the House that there will be enough feet on the ground to survey trees generally in the country to ensure that we do not have outbreaks of disease that are so devastating?

My Lords, however many feet we have on the ground, I do not think it would be possible for any government agency to cover the entire country in terms of the number of oaks there are and the number of oak processionary moths that might be processing around the country. All I am saying is that that particular outbreak was discovered in the summer of 2006. The Government moved as quickly as they could, but obviously they could not get on top of it. They managed to get on top of the outbreaks in Leeds and Sheffield and we have found no more two years after the attempt to eradicate them.

My Lords, would my noble friend take note of very recent research which indicates that there is a green health element not just in oak woods but in all our hardwoods? They are uniquely beneficial to many people suffering from psychological and mental ill health. Might this not therefore be an urgent issue that should be addressed more specifically than may be the case at present?

My Lords, that is another question, but I agree that trees are good for us. That is why we want, if possible, to eradicate or contain the oak processionary moth so that our oaks can flourish.

My Lords, at the moment the problem has largely been limited to London, although I echo the concerns of the noble Baroness and the way in which she raised them. I understand that there has also been an outbreak in Pangbourne in Berkshire, which is worrying because of the number of oak trees found in the wider rural area of that part of the country. Can the Minister give us some reassurance that everything is being done to tackle that outbreak? Furthermore, on resources, given that the end of April and the beginning of May is the crucial time of year for effective spraying, can I again ask the Minister to assure us that the resources are available to undertake such spraying work at the present time?

My Lords, of course I am aware of the outbreak in Pangbourne, which took place in 2010. It is too early to say whether we have eradicated the oak processionary moth because we cannot really talk about eradication until we have seen two years without any eggs or larvae around. We will report back in 2012 with the good news on that, if we have it. I shall repeat again what I said before: there are no problems with budgetary constraints in terms of fighting this problem.

My Lords, I doubt if the Minister knows the answer, but I would like to know what we are actually looking out for.

My Lords, one is looking out for a moth. It is called the oak processionary moth that exists on oak trees. It is called the oak processionary moth because it processes up oak trees in a processionary manner, whereupon it does what moths want to do. Being more serious, I should make it clear that Forest Research at the Forestry Commission is offering advice, particularly in the south-west London area, on identification. It is not just our officials and those from the Forestry Commission who will be identifying the moth—we want the public to be able to report on outbreaks as well.