Velvet Ants

One of the problems with entomology or the study of insects is that there are too many species. Hogue and Powell's book "California Insects" describes about 600 of the 28,000 or more species thought to live in the state. Unfortunately, most of these species are of little economic importance and as a result are either poorly studied or the studies have not been widely disseminated. Anecdotal information (those quirky facts of interest to docents and the general public) often does not make it into the literature.

Most of you on your walks have probably encountered ant-like insects with dense red, black, orange or white hairy coats. These insects, the so-called "velvet ants", are actually female mutillid wasps. The females are usually encountered moving swiftly along the bare surfaces where their size and coloration makes them conspicuous. Velvet ants are parasitic on ground-nesting bees and wasps (one reference also included flies and beetles). The massive exoskeleton and body sculpturing provides a good defense against attacks by the prey species. (Apparently, collectors need to drill the thorax in order to mount specimens.) Another defense is the queer squeaking noise produced by plates on the abdomen when the insect is held by the body. Before indulging your curiosity, please remember that the female is noted for another of its defenses, a powerful sting. Since mating opportunities seem to be rare and considerable effort is involved in satisfying the egg laying requirements, it is fortunate that the females appear to be long-lived insects.

About a 100 species are thought to exist in California. Most of these are nocturnal desert dwellers. The males are sometimes attracted to lights. Over the past 4 years I have encountered 5 velvet ants, all of which have been red. Four of these were females, found during the cooler parts of the day (morning or early evening). One of the females was investigating a number of openings in the bank along a dirt trail while another was moving quickly along the road from the Nature Center. I am not sure what the females eat but I found the male on a flower head of sweet fennel. How can you tell the difference between males and females? The males have wings. In some species, the males pick up the females for mating and can aid in their dispersal by transporting them across various barriers.

Needless to say, this is a poorly studied group of insects. As one researcher pointed out - because of their life style, you can spend a long time in the field without making a single significant observation. What information can you add?

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Ron Lyons (volunteer 1990-1999)
Chula Vista Nature Center, 1000 Gunpowder Point Drive, Chula Vista, CA 91910-1201