Photo of the Week – June 8, 2012

I’m sticking with a beetle theme this week, it seems.  My last post focused on the currently ubiquitous soldier beetle.  This one spotlights the dogbane beetle.

A dogbane beetle on a dogbane plant. Lincoln Creek Prairie – Aurora, Nebraska

Read more and see a face-to-face photo of this insect below…

The iridescent green dogbane beetle is so named because both the larvae and adults feed primarily (maybe exclusively?) on dogbane and milkweed plants.  The larvae feed on the roots and the adults feed on the leaves.  Since both dogbane and milkweed plants have the same bitter tasting milky sap, it seems an odd choice of food, but quite a few other insects (including monarch caterpillars) share the same narrow diet, so there must be something good about it.

Because of their relatively large size (about 1 cm in length) and their iridescent color, dogbane beetles are pretty easy to spot in prairies.  For some reason, I usually seem to see and photograph them on plants other than dogbane or milkweed.  Not sure what they’re doing on those other plants…  Regardless, yesterday morning I saw a bunch on dogbane plants, where they belong, so I stopped to take some photos.

They’re awfully cute, aren’t they?



This entry was posted in Prairie Insects, Prairie Natural History, Prairie Photography and tagged , , , , , , by Chris Helzer. Bookmark the permalink.

About Chris Helzer

Chris Helzer is the Director of Science for The Nature Conservancy in Nebraska. His main role is to evaluate and capture lessons from the Conservancy’s land management and restoration work and then share those lessons with other landowners – both private and public. In addition, Chris works to raise awareness about the importance of prairies and their conservation through his writing, photography, and presentations to various groups. Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press. He lives in Aurora, Nebraska with his wife Kim and their children.

10 thoughts on “Photo of the Week – June 8, 2012

  1. How do I differentiate dogbane with Japanese beetle? I know the latter prefers roses but not exclusively. Is the plant preference a clue? Thank you.

    • I’m no expert, but I think Japanese beetles are bigger (1.5 cm compared to 1cm for dogbane beetles) have brown elytra (wing coverings) and white spots around their tail end. Other readers may have better characteristics to look for.

  2. The Japanese beetle is quite different in morphological features and even in details of coloring. See the two bugguide images here:

    The sap chemicals of milkweeds and dogbanes are not identical, and while some feed on both, quite a few insects prefer one or the other, or even appear to be exclusive to either milkweeds or dogbanes.

  3. Long time reader, first time writer…
    If feeding exclusively on dogbane/milkweed, as well as, being conspicuous herbivores it’s safe to assume they are sequestering defense chemicals from the plant and saying to the world, ‘don’t eat me, I taste bad.’ One of my undergraduate instructors is the expert on the chemical ecology of Danaus (Monarch’s), here’s a great link,


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