Friday, 5 July 2013

Conker Tree Science 2013

High summer is just around the corner, which must mean that our conker trees are just beginning to turn blotchy - and so Conker Tree Science is launched for 2013. You can take part in the 'pest controller' mission over the next week, and take part in the 'alien moth' mission during the whole summer. Watch out for news about the 'bird attacks' mission which will start again at the end of the summer.

It appears that the very late spring this year has also had an effect on the horse-chestnut leaf-miner. My impression is that the leaf mines are currently smaller than I would expect for this time of year, and few have pupated (you can tell if they have pupated by feeling the underside of the mine - there is a small bump where the caterpillar has spun a cocoon and pupated). My impression is that the size of the leaf mines is also much more variable than I would expect at this time of year. In previous years all the mines of this generation have been pupating within a day or two of each other, but this year it is a lot more variable. Will your data confirm my impression? I look forward to receiving your results via the website or the leafwatch app.

These mines are only just beginning to form - they will probably pupate in a week or so. Photo taken on 4th July.

One of the few trees in south Oxfordshire that had mature mines, but it still has a lot of very small mines as well. Photo taken on 4th July.

This tree had very few leaf mines. Photo taken on 4th July.


  1. My trees this year, in Lincolnshire, are virtually unaffected this year after a very bad year last year. I did wonder if the hard, long winter had affected them. Conkers are developing well on both trees. Is this a general effect even round London?

  2. Thanks for the comment. Over the past week the trees (in Oxfordshire) do seem to be turning browner - but this usually happens in July, so it has been nice to enjoy them looking fairly green for so long this year!