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For Insects, Spiders & Their Kin
For the United States & Canada
Photo#269913
iron cross blister beetle - Tegrodera aloga

iron cross blister beetle - Tegrodera aloga
Wickenburg, Arizona, USA
What a beautiful bug. I've lived in Arizona most of my life and I've never seen this kind of beetle before. It was just walking across the street in downtown Wickenburb. April 26,2009
Is it poisonous? how common are these beetles? Anything you can tell me about them would be great.

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iron cross blister beetle - Tegrodera aloga iron cross blister beetle - Tegrodera aloga

Yes, sorta.
Yes, these are "locally common" insects that are sometimes abundant in a small area, for a short period of time. You could probably go for miles before you see another one, but there would be many....Yes, they are poisonous. They secrete a potent defensive chemical (cantharidin) from their body joints if squeezed. The chemical can raise painful, scarring blisters on sensitive skin. Ingested, the insect can be lethal, so keep curious kids from sampling one. Same goes for pets. I believe the larvae of these beetles are parasitic on other insects, but I'm not positive. Adults will eat foliage, and sometimes cause severe damage to plants in areas where the beetles are numerous.