The Moo-derer
Kelly’s Field Notes
Common Name: Velvet Ants aka Cow Killers
Order: Hymenoptera
Family: Mutillidae
Genera: There are around 230 genera of velvet ants!
Species of Note Near You (There are around 8000 species of velvet ants!):
Cow killer or red velvet ant (Dasymutilla occidentalis) - found in the north and southeast U.S. and west to Texas. This is the largest species 2.5 cm (1 in).
Sacken's or western velvet ant (Dasymutilla sackeni) - found in the Pacific Northwest.
Velvet ant (Dasymutilla asopus) - found throughout Australia.
Large velvet ant (Mutilla european) - found throughout Europe.
Velvet ant (Wallacidia oculata) - found throughout southeast Asia.
Velvet ant (Mutilla scabrofoveolata) - found in South Africa.
Description:
Velvet ants are wasps! They are related to ants (and bees, and sawflies) all belonging to order Hymenoptera. They range from 0.4 cm (0.15 in) to 2.5 cm (1 in). The females are wingless and resemble ants in appearance, but very fuzzy. Their carapace is hard! So hard it can be very difficult to pin one for your insect collection. They are usually bright red or orange, but can also be black, blue, silver, gold/yellow, white or any combination of those colors. As you may know from other episodes/notes these warning colors let predators know the velvet ant is not to be messed with! They are not aggressive, but if provoked females can deliver a nasty sting. Renowned entomologist Dr. Schmidt has one species as a 3 on his pain scale (Dasymutilla klugii), with a painful sting lasting 30 minutes.
Velvet ants are found nearly everywhere save Antarctica. Over 400 species are found in North America, concentrated in the southwest. Males and females are sexually dimorphic (look different), sometimes so much so it is tough to tell if a male and female belong to the same species!This is due to their very different living situations. Females tend to look like other female velvet ants. They are on the ground, motoring around, ready to sting if needed. Males, on the other hand, are out flying like other species of wasp. Because they are fairly defenseless compared to females, male velvet ants tend to look like other wasp species to trick predators into thinking they are dangerous. Both sexes can create a squeaking sound by rubbing two abdominal segments together. Females would prefer to squeak at you instead of stinging.
Velvet ants have a particular swaying gate. The book “Velvet Ants of North America” has a particularly on point description: “the locomotion of velvet ants resembles that of a sleep-deprived parent who is already 15 minutes late to an appointment (months in the making), searching for their car keys on a LEGO-strewn surface.” To me, velvet ants always look harried and busy, with no time for predators and interruptions.
Life Cycle:
Life for a baby velvet ant starts as an egg, laid by its mother, on the larva of another insect. This might be a beetle, or a caterpillar, or even another species of wasp or bee. One species (Odontophotopis sp.) has been reported using cockroach eggs as hosts. There is some controversy about this report as it may have been parasitizing the parasitoid wasp larva that was already on the roach egg. Velvet ants are parasitoids, similar to cicada killers, another wasp we have covered. But rather than hunting and provisioning a burrow with food for their offspring, velvet ants lay their eggs where their prey is already. For example, a female velvet ant will approach a beehive, push past the guard bees or intimidate them into hiding, and lay her eggs on the larval bees. Studies show bees don’t bother trying to sting velvet ants as their stinger can’t penetrate the carapace. They instead try to use their mandibles. Once inside the velvet ant finds a larval bee and leaves her egg attached. It takes about a week or two for larval velvet ants to kill their host. The velvet ant will then pupate in the nest.
Adults feed on nectar and pollen, though some studies have shown they eat larvae and pupae before they lay eggs on those remaining. Adults only live for a few weeks.
Super Powers:
Stinger - velvet ants pack a punch! Dr. Schmidt lists them as a 2-3 on the pain scale (depending on species). Velvet ants also have the longest stinger compared to their body size, with large species up to 1 cm (0.5 in) in length compared to their body length of 2.5 cm (1 in)! The sting is flexible like a hose, less like a rigid spear. This allows a female to sting from any angle, including behind her.
Squeak - she’d rather not sting, she’d much rather yell at you until you go away!
Funky Smell - velvet ants have a gland near their mandibles that secretes a gross smell. It’s been described as a “sweet-sour slightly fetid decay smell” in Velvet Ants of North America. Even more interesting, the chemicals involved mimic alarm pheromones in ants, sending them away from the velvet ant.
Armor Plated - velvet ants are made of tough stuff! Females are tougher than males (lack of wings gives the ability for thicker carapace) and their carapace is 11 times stronger than that of a honeybee. Their thorax is also fused into one plate, while other wasp species have multiple flexible plates. They are so tough they sometimes bend steel pins and are said to “sting from beyond the grave” because the pin slides off of the velvet ant and into your thumb.
Velvet Ants in Culture:
Female velvet ants are often kept as pets. They are hardy, very active, and fairly easy to keep. They are difficult to find bred in captivity if not impossible.
References:
Schmidt, Justin Orvel. Defensive Srategies of Wasps and Ants: Dasymutilla occidentalis and Pogonomyrex badius. University of Georgia, 1977.
Schmidt, Justin O. The sting of the wild. JHU Press, 2016.
Williams, Kevin, Aaron D. Pan, and Joseph S. Wilson. Velvet Ants of North America. Vol. 145. Princeton University Press, 2024.
Wikipedia Contributors. “Mutillidae.” Wikipedia, Wikimedia Foundation, 26 Apr. 2024, en.wikipedia.org/wiki/Mutillidae.