Large Velvet Ant

• GeneralIt is not an ant but a wingless wasp; its sting is intensely painful.
• Male and female are so different that for a long time they were described as separate species; they could only be linked by watching them mate.
• The female enters the bumblebee nest, opens the cells and lays an egg on the pupae, which her larva will devour.
• Its cuticle is extraordinarily hard and resistant to the stings and bites of the bumblebees defending the nest, and it also stridulates, producing an audible squeak when disturbed.
• It is not an ant despite the name: it is a wasp with extreme sexual dimorphism, the female wingless and covered in velvety hair and the male winged.
• The female enters bumblebee nests and lays her eggs on the pupae; the larva develops as an ectoparasite, eating the pupa from the outside.
• It parasitises mostly male pupae, and under experimental conditions it has been recorded dispersing up to twenty metres in a week and invading nests of different species.
• The sting of females in this family is proverbially painful, and their cuticle is so tough that it resists being crushed.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Meadows and sandy ground with bumblebee nests

Sexual maturity

Extreme sexual dimorphism: the female is wingless and searches for host nests on foot, while the male is winged and flies in search of females

Gestation / incubation

The larva develops as an idiobiont ectoparasitoid on the host's prepupa or pupa and kills it within one or two weeks

Litter / clutch size

The female pierces the wax wall of the bumblebee nest and lays the eggs on the surface of the prepupa; up to two eggs have been observed in a single cell

Sources consulted: Insects (2019), primer registro de parasitación sobre Bombus breviceps · revisiones de biología de Mutillidae · NCBI PMC6523353, parasitismo de Mutilla europaea sobre Bombus breviceps · NCBI PMC6523353, parasitismo de Mutilla europaea sobre Bombus · ficha de la familia Mutillidae · NCBI PMC6523353 · NCBI PMC7485775, revision global de hospedadores de mutilidos

Best time: The females patrol ground with a high density of host nests, mainly in the early morning and late afternoon to avoid the overheated soil of midday