QuestionsHow to growTrees and ShrubsPests and Diseasescaterpillars eating birch leaves 0 Vote Up Vote Down Paul Matthews asked 16 years ago My multi-stemmed birch is being atacked by greeny yellow caterpillars with black stripes about 2 cm long that are eating the leaves. Should I do anything about it such as spraying with a pesticide or just leave them to their meal? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago Live and let live! These do no significant harm, even with extensive leaf loss.