Dunbartonshire,
United Kingdom 
I have had bother with small yellow caterpillars eating my rowan tree leaves for the past two years around April/May there was hundreds of them last Spring. Can you tell me how to prevent them coming and what remedies I could perhaps employ against them as they are very destructive. Thanks Stephen.
20 Oct, 2015
at the first sign of caterpillars pick them off if you can reach. if not then a commercial insecticide will do the trick. but have you tried to identify them? photos of them will gives a better idea of what we are dealing with.
20 Oct, 2015