Insect Identification logo

Cow Killer (Dasymutilla occidentalis)

Detailing the identifying qualities of the Cow Killer, including physical features and territorial reach.

 Updated: 8/3/2017; Authored By Staff Writer; Content ¬©

  Cow Killer  
Picture of Cow-Killer

Do not touch! The visual warnings abound on the Eastern Velvet Ant, which is actually a solitary wasp.

The Eastern Velvet Ant (aka: "Cow Killer") is not an ant at all, though it looks like a hairy one. It is actually a wasp and the female has a severely ferocious sting that is rumored to be strong enough to kill cattle. It is extremely painful and this insect should not be handled.

Males have wings and look more like a typical wasp though they still retain some hairs on their body. Females do not have wings, but they can and do sting. The Eastern Velvet Ant is a solitary wasp meaning they do not congregate in nests with hundreds of others of their kind. They are also parasitic to bumble bees.

Females lay eggs in a bumble bee's hive. Once the wasp's eggs hatch, theses larvae eat the larvae of the bumble bee. Adults drink nectar.

Cow Killers can be found in fields, meadows, sandy areas and the edges of forests. They are typically most active at dusk or during the night. Though the female looks like an ant, her warning coloration and ferocious sting are enough defensive adaptations to keep most predators (and curious animals) at bay.

Picture of the Cow Killer
Picture of the Cow Killer

Cow Killer Information

Category: Bee, Ant, Wasp and Similar
Common Name: Cow Killer
Scientific Name: Dasymutilla occidentalis
Other Name(s): Eastern Velvet Ant

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Hymenoptera
     Arrow graphic Family: Mutillidae
      Arrow graphic Genus: Dasymutilla
       Arrow graphic Species: occidentalis

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 15 mm to 25 mm (0.585 inches to 0.975 inches)
Identifying Colors: red; black
Additional Descriptors: hairy, ant, stinging, wasp, harmful

North American Territorial Reach (Though Not Limited To): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

Images Gallery


BugFinder: What is it?