"Cow Killer" Velvet Ant (Dasymutilla occidentalis)

"Cow Killer" Velvet Ant (Dasymutilla occidentalis) -- Female

Like all Velvet Ants this Cow Killer isn't an ant at all. She is a wasp, a flightless, female wasp. (Males have wings and can fly.) Female Cow Killers are in constant motion, scurrying along the ground, presumably searching for bumblebee nests. Once a nest is found, she will dig down into the nest and deposit one egg near the brood chamber. When the egg hatches the larva of the Dasymutilla will enter the bumble bee brood chamber, kill the bee larvae, and feed on them. The Cow Killer larva pupates in the bumble bee brood chamber.

The common name "Cow Killer" is based victim's reports that the sting of the female are painful enough to kill a cow. Like most wasps, the male cannot sting.

"Cow Killer" Velvet Ant (Dasymutilla occidentalis)

Cow Killer

"Cow Killer" Velvet Ant (Dasymutilla occidentalis) - Female

Despite the name and superficial appearance, velvet ants really are not ants. They are wasps. There are many different species. The one shown above is the most common. Females are wingless, but males have wings. The males of this particular species look very much like the females, except for those wings.

Cow Killer larvae are parasites of bumble bees. The females locates a bumble bee burrow, digs down and lays an egg. When the egg hatches, the larvae invades a bumble bee brood chamber where it consumes the bee larvae. The velvet ant larvae then pupates in the bumble bee brood chamber and emerges as an adult.

When you find these females velvet ants in nature, they usually remain in constant motion. That's why I had to do a "catch and release" on this female in order to get her photo. Females can deliver a painful sting. In fact the sting hurts so much it is said to feel as if it could kill a cow; hence, the common name. I haven't conducted any personal research into velvet ant stings, and don't intend to.

Cow Killer