Desert Spider Beetle

Black Beetle with Yellow Spots
April 30, 2010
Hi! There is an interesting black beetle with yellow smudges scurrying all over the San Felipe Baja desert this Spring. They are super fast, very aggressive, they will chase after you if you get too close! They’re bigger than a quarter.
Baja Beetle girl
San Felipe, Baja California

Desert Spider Beetle

Hi Baja Beetle girl,
The Desert Spider Beetle or Inflated Beetle is a Blister Beetle in the genus Cysteodemus, and you may read up on them on bugGuide.  We believe it is Cysteodemus armatus which Bugguide describes as:  “Flightless; distinguished from all other meloid beetles by its inflated (air space below elytra may serve as insulation), spheroid, fused elytra. Elytra are coarsely pitted, and often covered with a white to yellowish secretion.

Desert Spider Beetle

OMG!!!!!  you are a genius!
Thank you Thank you Thank you!  That’s totally it!!!!
Kym S. Farmen – Master Herbalist, Photographer

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