The velvet ant, known for its vibrant colors and fuzzy exterior, is often mistaken for a true ant. Despite its common name, this insect is actually a type of wasp with unique biology and defense mechanisms.
Appearance and Identification
Velvet ants, members of the family Mutillidae, have bodies densely covered with hair, giving them a velvety texture. These hairs often exhibit bright, contrasting colors such as scarlet, orange, black, white, silver, or gold, serving as a warning to predators. The coloration can vary, with some species like the “cow killer” (Dasymutilla occidentalis) featuring bright red and black patterns.
A notable characteristic is their sexual dimorphism. Female velvet ants are wingless, resembling large, hairy ants, and are often seen moving across the ground. In contrast, the males possess wings and typically have a more wasp-like appearance. Both sexes have a robust exoskeleton, which is unusually tough and provides protection. Velvet ants generally measure between 0.5 to 1 inch in length.
True Identity and Biology
Despite their ant-like appearance, particularly the wingless females, velvet ants are not ants; they are solitary wasps in the family Mutillidae. This resemblance is a form of mimicry that helps deter predators. Unlike true ants, which are social insects, velvet ants are solitary organisms, with each female operating independently.
Their life cycle involves complete metamorphosis. Female velvet ants use a parasitic reproductive strategy, primarily targeting the nests of other ground-nesting insects, such as solitary bees and wasps. The female lays a single egg near or on the host’s larvae or pupae. The velvet ant larva then consumes the host, developing as an ectoparasitoid.
Its Notorious Sting
Velvet ants are known for their painful sting, earning species like Dasymutilla occidentalis the name “cow killer.” This name comes from folklore suggesting the sting could kill a cow, though there is no evidence for this. Only wingless female velvet ants possess a stinger, which is a modified ovipositor; males are stingless.
The pain from a velvet ant sting is rated highly on the Schmidt sting pain index, with species like Dasymutilla klugii and Dasymutilla occidentalis scoring a 3 out of 4. Despite the intense pain, the venom is not medically significant to humans and is less toxic than a honey bee’s. These wasps are not aggressive and sting only when provoked or handled.
Where They Live and What They Do
Velvet ants are found globally, with a significant diversity of species in arid and semi-arid regions. In North America, their range extends across the United States, from Florida to Connecticut and Pennsylvania, westward into Texas, Colorado, and Kansas. They prefer sunny, warm, and dry conditions, often with sandy soil, such as pastures, fields, meadows, and forest edges.
Adult velvet ants are solitary and do not form social colonies. Females are often observed moving across the ground, searching for host nests to parasitize. Adults feed on nectar from flowering plants, contributing to pollination. When disturbed, females may produce a squeaking or chirping sound by rubbing abdominal segments together, serving as an auditory warning.