This week, I came across a yellow, fluff-covered insect crossing the gravel path near the power lines. But don’t let the fuzzy exterior fool you: velvet ants are fast-moving predators with an impressive array of defensive capabilities.
As is often the case with insects, the common name is deceiving. This is a solitary wasp, not an ant. Female Mutillidae family wasps are wingless. They survey the ground looking for places to leave their eggs. Velvet ants parasitize pupae and cocoons of ground-nesting insects, often bumblebees or other wasps. Their larvae eat the host and emerge as adults in late spring.
It took me a few minutes to see the wings on this male. Adult Mutillidae males have been found on flowers, as they eat nectar. Sometimes, male velvet ants look so different from females that they’ve been labeled as separate species.
The female pictured here has lost most of her velvet, but you can see the body and head much easier. We found her on an insect walk a couple of years ago. She is a Dasymutilla aureola, which have heads wider than the thorax and live in the western U.S. Females prefer open, arid areas, and I’ve seen them scurrying across paths at Mount Pisgah a handful of times.
Now for their security detail: Velvet ants wear warning colors: bright yellow, red, and orange. They can emit a “stay away” squeak and a defensive odor when they’re threatened. Mutlillidae can run fast, 5.5 inches per second, and their exoskeletons are 11 times tougher than a honeybee. To top it off, females have a potent sting: One species, not found in Oregon, is hyperbolically known as a “cow killer.”
Given all these weapons, it’s no wonder a 2018 study showed that, in more than 100 encounters with potential predators (lizards, toads, shrews), only one velvet ant was eaten.
See more of Karen’s work here.
Informative article from the U.K.: https://www.nhm.ac.uk/discover/velvet-ants-flamboyant-and-fuzzy-with-extreme-ppe.html
Good info from UC Riverside: https://entomology.ucr.edu/we-ch-9-2#velvetants