1. The emergency felling carried out last summer was designed to reduce the number of galls (and the wasps they contained) present on sweet chestnut and hence reduce the chances of spreading as wasps emerged in July.
  2. In order to further reduce the chance of spread further coppicing was anticipated over the winter of 2015-16. The premise being that we were unlikely to have dealt with every gall and any wasps emerging from those galls would  have laid eggs on chestnut nearby.
  3. This work was reinforced by:
    1. the use of ‘sticky’ traps (which were set to capture a sample of flying wasps);
    2. computer modelling of likely distribution; and
    3. surveys in November, when we found that some leaves were retained around buds distorted by galls after other leaves dropped normally, hence we inspected for hanging leaves and found galls further into the wood.
  4. Consequently a Statutory Plant Health Notice was issued asking Sevenoaks District Council to coppice a further 10 hectares over the winter 2015-16 (copy attached).
  5. Sevenoaks engaged a local contractor and coppicing has been progressing well and we hope will be completed no later than the end of May (ideally this would have been completed earlier but wet ground conditions delayed progress).
  6. In March we took samples of the sweet chestnut regrowth post last summers emergency felling and carried out tests to identify any signs of OCGW in the buds (where adult wasps emerging from any galls, which had not been destroyed, would have laid eggs). We were very pleased that no signs of OCGW were found.
  7. Forestry Commission surveyors will shortly start to survey again for new galls on the fresh buds.

Matthew Woodcock
Partnership and Expertise Manager South East
Forestry Commission – South East & London


5th August 2016 -Latest Update

The Parish Council had received the following update on the control of the Gall Wasp:

  1. The mulch pile which is of concern to the Environment Agency – Forestry Commission are arranging for a contractor to clear at their expense.

  2. Coppicing under the pylons – has been completed – making a total of some 25 acres (10 hectares) cleared. This relates to approximately 15% of the area of Farningham Woods.

  3. Scout Camp area – coppicing will now start adjacent to the ride running up from the mulch pile past the Scout Camp.

  4. Scouts – Sevenoaks District Council (SDC) will be talking to the Scouts about clearance on their land.

  5. BBC – SDC understand that the Forestry Commission will be speaking to BBC on site today (5 Aug) about the work that has gone on to try to halt the spread of the Oriental Chestnut Gall Wasp.

  6. Regrowth – Forestry Commission has instructed that SDC has no longer to to cut and burn the regrowth on coppicing (stools) undertaken last year.

  7. Clearing the timber – SDC are awaiting clearance from Forestry Commission to remove cut timber off the site. The problem seems to be that some trunks may have some leaves attached and they need to be confident that any galls not burned along with the top growth are going to be destroyed by the purchaser’s production processes.

  8. Long-term control – Department for Food & Rural Affairs and Forestry Commission are considering the introduction of a gall wasp parasite, but this may not be for three or more years.


Matthew Woodcock, Forestry Commission: Apologies for not responding sooner. As you appreciate when the Oriental Chestnut Gall Wasp (OCGW) was first identified in Farningham Woods this was the first finding in the UK. As such we were very pleased at how helpful both yourselves and Sevenoaks District Council were in helping reduce the opportunity for dispersal of OCGW by recoppicing sweet chestnut and destroying the galls from which the wasps emerge in early summer. You will recall the time-frame between identification of the wasps and emergence from the galls was very short. While that work was progressing survey work was carried out widely to see if OCGW was present in any other parts of the country. A small group of street trees in St Albans were found with galls and these were also destroyed.

The following spring Farningham Woods were monitored regularly, and wider surveys were carried out. During these wider surveys OCGW was identified in a number of sites across London and hence it was concluded that eradication was not possible, however, work is ongoing to explore whether native hyperparasites which attack oak gall wasps will maintain the chestnut gall wasps at an endemic level or whether a hyperparasite which attacks the gall wasps in its native range might be introduced to maintain the population at an endemic level.

In the interim we are very pleased that Sevenoaks District Council have revised the Woodland Management Plan for Farningham Woods and worked to restore the traditional coppice management. As well as helping maintain the diversity of woodland habitats coppice management delivers this improves resilience to storms and will help reduce the speed of spread of OCGW while work on the hyperparasite continues.

FC continues to visit the woods to monitor progress and I noted at my last visit that the coppiced areas are regrowing well and that OCGW galls are also present. FC will continue to monitor progress. Site management remains with Sevenoaks DC