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 bright scarlet or orange, but may also be black, white, silver, or gold. Their bright colors serve as aposematic signals. They are known for their extremely painful stings,, and has resulted in the common name "cow killer" or "cow ant" being applied to the species Dasymutilla occidentalis. However, mutillids are not aggressive and sting only in defense. In addition, the actual toxicity of their venom is much lower than that of honey bees or harvester ants. Unlike true ants, they are solitary, and lack complex social systems.
Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit. The benefit to Müllerian mimics is that predators only need one unpleasant encounter with one member of a set of Müllerian mimics, and thereafter avoid all similar coloration, whether or not it belongs to the same species as the initial encounter. It is named after the German naturalist Fritz Müller, who first proposed the concept in 1878, supporting his theory with the first mathematical model of frequency-dependent selection, one of the first such models anywhere in biology.
Aposematism is the advertising by an animal, whether terrestrial or marine, to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm.
Dasymutilla gloriosa, sometimes referred to as the thistledown velvet ant, is a member of the genus Dasymutilla. Only females are wingless, as in other mutillids. Compared to other mutillids, it is mid-sized, being larger than some of the smallest known species like Dasymutilla vesta but smaller than some of the largest known species like Dasymutilla klugii. It ranges from Utah, Nevada, California, Arizona, New Mexico, Texas and south into Mexico.
Dasymutilla occidentalis is a species of parasitoid wasp that ranges from Connecticut to Kansas in the north and Florida to Texas in the south. Adults are mostly seen in the summer months.
Pepsis grossa is a very large species of pepsine spider wasp from the southern part of North America, south to northern South America. It preys on tarantula spiders, giving rise to the name tarantula hawk for the wasps in the genus Pepsis and the related Hemipepsis. Only the females hunt, so only they are capable of delivering a sting, which is considered the second most painful of any insect sting; scoring 4.0 on the Schmidt sting pain index compared to the bullet ant's 4.0+. It is the state insect of New Mexico. The colour morphs are the xanthic orange-winged form and the melanic black winged form. In northern South America, a third form, known as "lygamorphic", has a dark base to the wings which have dark amber median patches and a pale tip.
Euspinolia militaris is a species of wasp in the family Mutillidae. Though it is a wingless wasp, it has sometimes been referred to by the name panda ant.
Dasymutilla aureola, also known as the Pacific velvet ant, is a species of velvet ant in the family Mutillidae, found in the western United States.
Dasymutilla sackenii, also known as Sacken's velvet ant, is a species of velvet ant, actually a type of wasp. It is found in Oregon, California, Nevada, Baja California, and Baja California Sur. As with most velvet ants, the males have wings and the females are wingless. The females of this species have cream-colored fuzz (setae) on their backs and black fuzz on their ventral side and legs. D. sackenii is most commonly observed May through October; observations December through February are very rare.
Dasymutilla arachnoides is a species of velvet ant found in North America. The female displays a "trifoliate pattern of black setae on tergum II." This species is widespread in Mexico and Central America as far south as Honduras.
Dasymutilla coccineohirta is a species of velvet ant found in North America. Coloration on the females is variant, ranging from red to white. It is found along the Pacific coast as far north as Washington and Idaho and as far south as Baja California state.
Dasymutilla creon is a species of velvet ant found in North America. Specimens have been collected from Kansas south to Texas and as far east as North Carolina.
Dasymutilla flammifera is a species of velvet ant found along the Pacific coast of North America and inland to Idaho and Arizona.
Dasymutilla foxi is a species of velvet ant found in Mexico and the southwestern United States. Dasymutilla foxi is locally common, and "setal coloration is highly variable; each of the body segments varies from whitish to reddish, and most eastern populations have a black setal patch on the mesosoma."
Dasymutilla gibbosa is a species of velvet ant found in the northeastern United States in North America. C. E. Mickel placed D. gibbosa in the Quadriguttata group of the genus.
Dasymutilla thetis, also known as the minute thistledown velvet ant, is a species of velvet ant known only from Arizona in North America. It was first described by Charles A. Blake as Sphaerophthalma thetis in 1886. Individuals are about 7 mm long. Females are "clothed entirely with ivory-white setae."
Dasymutilla gorgon is a species of velvet ant native to central North America from Colorado to Louisiana.
Dasymutilla leda is a species of velvet ant native to North America. Found in the central United States from South Dakota to Texas, only females have been collected by scientists but "distribution and coloration suggest that D. myrice may be the male of this species."
Dasymutilla montivagoides is a species of velvet ant native to North America. The species is found in the central United States, specifically Texas, New Mexico, Oklahoma, and Kansas.
Dasymutilla nigripes is a species of velvet ant native to North America. This species is widespread throughout the United States and is also found in Alberta in Canada.
