''Dasymutilla occidentalis'' (red velvet ant, eastern velvet ant, cow ant or cow killer) is a species of

parasitoid wasp Parasitoid wasps are a large group of hymenopteran Superfamily (zoology), superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, ...

that ranges from

Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

in the north and

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

in the south. Adults are mostly seen in the summer months. The eastern velvet ant is the largest of the velvet ant species in the eastern United States, attaining an approximate length of 0.75 in (1.9 cm). Adults display aposematic coloration, consisting of black overall coloring with an orange-red pattern on the dorsal surface of the thorax and abdomen.

Characteristics and description

Commonly mistaken for an ant because of its appearance and its common name, it is a

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

wasp species in which the females are wingless, as is true for all females of

Mutillidae Velvet ants (Mutillidae) are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants. Their common name velvet ant refers to their resemblance to an ant, and their dense pile of hair, which most often is br ...

. It can be recognized by its distinctive coloring, black with bright red on the upper side of the head, thorax, and abdomen. They are quick-moving and often take a defensive posture when threatened. Unlike the females, males have dark, translucent wings and do not possess a stinger.

Ecology

''Dasymutilla occidentalis'' plays an ecological role as parasites and prey.

Defense

''Dasymutilla'' species have multiple defensive strategies, but are best known for their extremely painful sting, ranked 3 out of 4 on the Schmidt's sting pain index, earning them the nickname of "cow killer". Cow killer defenses include a thickened exoskeleton, the ability to run fast and evasively,

warning coloration Aposematism is the Advertising in biology, advertising by an animal, whether terrestrial or marine, to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the pr ...

, stridulatory warning sounds, a chemical secretion, and venom. Both sexes make a squeaking noise (

stridulation Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mech ...

) to warn potential predators (another form of

aposematism Aposematism is the Advertising in biology, advertising by an animal, whether terrestrial or marine, to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the pr ...

in females, and

automimicry In zoology, automimicry, Browerian mimicry, or intraspecific mimicry, is a form of mimicry in which the same species of animal is imitated. There are two different forms. In one form, first described by Lincoln Brower in 1967, weakly-defended ...

in males). When stridulating, velvet ants rub their abdominal segments together in a rapid fashion. This is different than stridulation seen in insects such as crickets, in which the leg structures are rubbed against the abdomen. ''D. occidentalis'' and related species are well known for their Mullerian mimicry. Mullerian mimicry occurs when species with pre-existing defenses adopt similar colorations and patterns to increase the fitness of all species involved. North American velvet ant species comprise one of the most intricate Mullerian mimicry rings in the natural world, being divided into eight separate rings of mimicry. Their behavior and coloring has been used to study how aposematic coloration works in the wild.

Reproduction and life cycle

Like most wasp species, velvet ants live solitary lives. Males take to the air to detect pheromones released by females. Males will fly towards female stridulation sounds as well. Once a receptive female is located, the male will carry the female in his mandibles and move her to a place he deems "safe" to mate. These mating spaces are often shaded and away from potential mating competitors. Both males and females stridulate during the mating process. Once the mating process is finished, the female begins looking for eggs and larvae of host species. Females are believed to mate only once in their lifetime. After mating, females seek out the brood cells of

Eastern cicada killer ''Sphecius speciosus'', the eastern cicada-killer wasp, is a large, solitary Wasp, digger wasp species in the Family (biology), family Bembicidae. They are so named because they hunt cicadas and provision their nests with them. Cicada killers exe ...

s and horse guard wasps as well as other large ground-nesting members of

Crabronidae The Crabronidae is a large family of wasps within the superfamily Apoidea. Taxonomy and phylogeny This family has historically been treated as a subfamily in the now-defunct Spheciformes group under the family Sphecidae. The Spheciformes inclu ...

, where they sneak into the nest and deposit an egg onto a host

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

. The egg quickly hatches into a white, legless grub, which consumes the host larva and goes through several larval stages prior to

pupa A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

tion. Pupation typically takes 23 days.

References

External links

* {{Taxonbar, from=Q5227023 Mutillidae Hymenoptera of North America Insects of the United States Aposematic species Wasps described in 1758 Taxa named by Carl Linnaeus