The deadly ash die back disease is now "carpeting" woods where it was first discovered and is poised to infect trees across the country in the coming weeks.
Lethal white fruits have emerged in woods in Norfolk one of the first sites where the disease was found in October 2012
Just one fruit was seen in June but two months later the woodland is covered with the killer fungus.
Dr Anne Edwards, of the John Innes centre, who discovered the disease in Ashwellthorpe Wood, revealed: "In June of this year we found the first of the fruiting bodies in the wood and these are structures which will go on to infect other trees.
"In June it was quite hard to find these but I went yesterday to the woods and there were carpets of them everywhere ready to spread to the rest of the country. Quite depressing really.
"That is the stage we are at now. They are ready to infect the rest of the country. We can only hope there will be a westerly wind to blow it back to Europe."
The bad news came as scientists launched an online computer game on Facebook to help fight ash die back.
The simple game called Fraxinus is based on the real-life DNA letter sequences of ash trees and the deadly fungus chalara fraxinea. It uses the skills of online game players to find patterns in the strings of genetic information.
By finding matches and differences in the strings scientists hope to exploit areas of resistance in the genetic make-up of ash trees and the most dangerous parts of the fungus.
The game exploits the fact that the human mind is, surprisingly, far better than computers at finding complex matching patterns and variations. Computers make too many mistakes.
The raw DNA data has been translated into different coloured leaves for the game. Players score points for matching the leaves to a top line.
Russell Stearman, game designer at Sheffield based Team Cooper, said: "You won't need a degree in gene sequencing to understand or play the game. It should be as easy to play as Candy Crush.
He said players would not always be able to match up the lines perfectly and where they did not fit would give scientists clues to vulnerabilities in the fungus or ways to develop disease resistant trees.
"All the games have been selected to find trouble spots which will be really useful for scientists to look at. We hope this game will break down barriers between scientists and the outside world."
Dr Dan Maclean, head of Bioinformatics at the Sainsbury Laboratory, said: "Genetic variation is the key to all this. Genetic variation is basically the differences in between every living thing.
"Playing the game is doing real science and the results the human players give us will go straight back into the databases. It is clear people can make a genuine contribution which ultimately could make a real difference."
It is one of the first such real science online games but others, involving cancer, are being developed.
