The Thistledown Velvet Ant

Wetlands Park Friends

DON’T REACH FOR THAT MOVING PIECE OF WHITE FLUFF NEAR THE CREOSOTE BUSHES!!! Thistledown velvet ants (Dasymutilla gloriosa) are actually wasps and the wingless females have long stingers and really painful stings.  

Thistledown velvet ant females look very much like the fruit of the creosote bush – soft and fuzzy. Their gait even seems to “tumble” them along the ground. In fact, one long-time explanation for their white color is that it evolved as camouflage. Dr. Joseph Wilson of Utah State University recently researched another explanation. Creosote bushes “arrived” in the Mohave Desert about 100,000 years ago from their original home in South America. Wilson says the wasp’s white fossil ancestors are five million years old. It was white long before the creosote bush got here! 

So, if not camouflage, then what? Wilson’s research indicates that the white color keeps the wasps cooler by reflecting the sun. This allows the wasps to be more active in the summer heat to search for the burrows of other wasps, where they lay their eggs.

The male Thistledown looks completely different, with black wings, head and thorax and yellow abdomen. You would never guess they are the same species. Amazing! 

To see the female Velvet Ant in action, check out this YouTube video: 

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