Velvet Ants

Velvet Ants (aka “cow killer”) are actually wasps. Females are wingless and covered with dense hair, superficially resembling ants. The largest velvet ant species reaches about 3/4 inch in length. They are black overall with patches of dense orange-red hair on the thorax and abdomen. Males are similar looking but have wings and cannot sting.

Life Cycle: Females seek the immature stages of ground-nesting bees, digging to the nesting chambers and eating a hole through the cocoon. She deposits and egg on the host larva, which soon hatches into a white legless grub. The immature velvet ant eats the host larva, developing through several larval stages before forming a pupa.

Mouthparts are for chewing. Lone females can be found crawling on the ground, particularly in open sandy areas. Adults are most common during the warm summer months. Larvae are solitary, external parasites of developing bees, immature wasps (Vespidae and Sphecidae), and some other insects such as beetles and flies.

The common name, “cow killer,” is thought to describe the painful sting these insects can inflict to man and animals, although it is doubtful that many cows are actually stung, much less die.

The exoskeleton of all velvet ants is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for display). This characteristic allows them to successfully invade the nests of their prey and also helps them retain moisture.
Only the female is capable of inflicting a sting because the stinger itself is a modified female organ called an ovipositor. Female velvet ants have unusually long and maneuverable stingers.

Velvet ants are rarely plentiful enough to become a nuisance. They usually remain outdoors, in warm, sandy areas. They should never be picked up by hand, or stepped on with bare feet. Due to an extremely tough exoskeleton, chemical and mechanical control are not very effective.