Dogbane Leaf Beetles shine at creek margins during low flow

Dogbane Leaf Beetle (Chrysochus auratus) are at peak activity along the Eastside corridor this week — their metallic green-and-copper shells catching the July light in a way that stops people mid-step. Two observations turned up on the 25th, both clustered where dogbane clings to the rough margins near Onondaga Creek, with a third sighting recorded earlier in the month at Gateway Center.

The beetles feed almost exclusively on dogbane, a native plant toxic enough to deter most insects. That specialization means they track wherever the plant holds on, which tells us something about both the dogbane and the ground it roots in. Right now the creek is running at 21 cubic feet per second at the ONONDAGA CREEK AT SPENCER STREET, SYRACUSE NY gauge — the kind of slow summer flow that concentrates whatever enters it. The beetles' presence at the dogbane margins is not a health clearance for the water, but it does say the plant is present and holding on, which suggests the ground beneath it retains some ecological resilience even as the water flows thin and stressed.