Finding dogbane beetles
Dogbane beetles are small, about 10mm, a little bigger than a ladybird beetle. They have stunning iridescent colors that change as the light catches the beetle at different angles. The colors range from greens to orange-red with hints of blue:
The scientific name is Chrysochus auratus. They are named for the plant, Dogbane. The beetle spends its whole life cycle on or around the Dogbane plant, so the most reliable way to find the beetle is to look for Dogbane. According to what I’ve read, Dogbane beetles feed exclusively on plants in the Dogbane family (Apocynaceae), including Apocynum cannabinum and Apocynum androsaemifolium.
In my area, I find them on Speading Dogbane (Apocynum androsaemifolium), a bushy plant with slender stems and blue-green, oval leaves. The photograph shows a Spreading Dogbane leaf. Spreading Dogbane starts flowering in June. The flowers are small pink bells; the flowers attract butterflies. I find Spreading Dogbane in sunny upland meadows and hillsides. It’s easiest to find the plant when it is in flower, and easy to recognize, and start looking for the beetle. Dogbane is a toxic plant, dangerous to children and pets (hence the name) that eat it.
Chrysochus auratus is found in the eastern US. In the northeast, bug lovers find Dogbane beetles from June through August. I find them in later summer more often, usually in July or August in my area, after the flowers are spent. They lounge around the plant and are pretty tolerant of observers. One plant can have several beetles. Because they are so reflective, wait for a cloudy day or use early morning light when you photograph them.