Our conker trees are under attack by 'alien' invaders!

Have you noticed whitish patches on the leaves of horse chestnut trees?  By the middle of summer, the whitish patches die and turn brown.  Sometimes whole trees turn brown, and it looks like autumn has come early.

The damage is caused by a tiny 'alien' species of leaf-mining moth, which is invading the UK.  For biologists, an 'alien' is a species not naturally found in an area or habitat.  The moth’s caterpillars eat the leaves from the inside.  Infected trees are weakened, and produce smaller conkers.

Can birds or bug-eating bugs save the trees?

Luckily, there is help at hand.  Some of the leaf-mining moths are killed by birds that prey upon the caterpillars. Others are killed by natural pest controllers, in the form of tiny insects.  These insects lay their eggs inside the caterpillars of the leaf-mining moths, and when the eggs hatch, the larvae slowly eat the caterpillars, eventually killing them.

The brand new mission: bird attack has now started!

What can we do?

Scientists are finding out more about the invading alien moths and the pest controllers - see the video for more information.

Joining in today. Register today to receive news about the research and reminders when to take part. Your missions, should you choose to accept them, are:

Mission: alien moth survey - from 15 June 2012

• Take part anywhere in the UK!
  
• Help to find out how far the invading moth has spread and the damage it is causing, by submitting records from your area.
• Find out what to look for.
• Take part in the Mission: alien moth survey with our Leaf Watch app for iPhones and Android smartphones.

Mission: pest controllers - from early July 2012

• Help to discover how many alien moths are being killed by pest controllers, by collecting leaves and recording which insects hatch out from them.
• Help to find out whether the number of pest controllers varies locally, depending on how long ago the invasion started.
• This mission is for everyone who can find an affected horse chestnut tree.
• Register to receive a reminder when the mission starts.

Mission: bird attack - from 28 August

• Help to discover how birds are responding to the alien moths. Are they attacking the caterpillars?
• This mission is for everyone who can find an affected horse chestnut tree.
• Register to receive a reminder when the mission starts.

Do you choose to accept your missions? 

Register your interest to receive the results of our research, and to accept the missions.

Click here to find out more about the missions.

Read the project blog for the latest news.

Damaged leaf, showing whitish leaf mines 
(photo: Michael Pocock)

Michael Pocock, one of the scientists studying the moths, explains his research

A tiny alien moth that got away from the pest controllers
(photo: Rich Andrews)

Collect leaves like these to find out more about the alien moth and the pest controllers
(photo: Rich Andrews)