I've just discovered CartoDB which is a new programme for simply visualising graphically data.
Here are the nearly ten thousand records (9129 be precise) that were submitted over the last 4 years via the Conker Tree Science website or the LeafWatch smartphone app. The image cycles through the time from June 2010 until the end of 2013.
White shows where the horse-chestnut leaf-miner was recorded to be absent, while yellow through to red shows increasing levels of damage.
It is worth noting that this map includes all records of the horse-chestnut leaf-miner including unverified records. In the formal maps of distribution (here) only verified records were included. So far the moth has not be confirmed north of Newcastle. Up to 2010 It spread through Britain at about 20km per year but strangely has been stuck at Newcastle for the past 3 years.
Thank you to everyone who took part in Conker Tree Science and made this possible. The first scientific paper from the project is being released tonight, which is very exciting. More news on that in the morning!