I’ve had several young trees badly damaged by leopard moths (Zeuzera pyrina) this year. This spring the top half of a first-year apple tree was killed, and a young oak was severely damaged. (In the case of the oak I was able to kill the caterpillar with a wire and block up the tunnel, and so far the tree has survived.) In the summer I found a huge gallery that I’d missed on a larger apple tree, where the caterpillar had destroyed roughly half the circumference of the tree about 10cm above ground level, and had already pupated and hatched.
Last week the top of a small walnut tree was killed, and today I’ve discovered damage in three young apple trees. It’s incredibly frustrating.
I seem to recall reading that the adult lays eggs near the base of the tree (although the damage has fortunately been mostly near the tops of the trees), and that keeping weeds away can help discourage it. But all of the trees I’ve found it in recently have been kept fairly weed-free. I thought I’d read about whitewashing the trunk to discourage the adult from laying eggs on the tree, but today I read that the caterpillars can be carried from tree to tree by the wind on silk threads…!
Does anyone have any good solutions?