Answer: Based on your description it sounds like the trees are carrying honey locust plantbugs (Diaphnocoris chlorionis). If the trees seem very healthy, you may not need to control them. They do most of their damage when they first hatch, about when the buds open on the tree, mature around the end of May and disappear in July. If the leaves are widely distorted or show holes or spots, or if the trees are losing their leaves, then you may want to treat them with carbaryl (Sevin). Since the trees are so large, you may have to have them professionally sprayed.
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