On a recent adventure into the Ishi Wilderness…(http://en.wikipedia.org/wiki/Ishi_Wilderness) I stumbled onto my second Velvet Ant (Mutillidae) in California. This one was similar to the first species I saw. There are a few images below that show the first one I collected. Mike also found a Velvet Ant that looked to be the same species. Velvet ants are so named because of their dense hair that can be gold, black, orange or a variety of other colors. I have both specimens in captivity now. One fascinating thing I found about these ants is they make squeaking noises by stridulation which means that they make sounds by rubbing together parts of their body. Other common names for these ants include Cow Killers or Solitary Ants. The sting from the Mutillids is supposed to be very painful; fortunately I have not been stung by one yet. The name Cow Killer comes from the joke that the sting is painful enough to bring down a cow. If anyone can give a species ID or a key for mutillidae please comment.
The interesting about these “Ants” is that they are not ants. Velvets ants are wingless wasps in the superfamily Vespoidea. The females are most commonly found since they are apterous (without wings), males however are winged and show great sexual dimorphism from the female. Once mated, the females will invade ground nesting insects. Insect host include solitary bees, flies, Limacodidae moths, beetles and cockroaches. The female will lay haploid and diploid eggs on the exterior of the host. The host development stops upon egg eclosion (the emergence of a larvae from an egg or an insect from a pupa case) making this a parasite that lives on the outside of its host and kills its host in the process (idiobiont ectoparasatoid). The diploid eggs are fertilized and become females the haploid eggs are unfertilized and emerge as males.