What to Know About Velvety Ant Identification

 

About 480 species and 12 genera of velvet ants occur in North America north of Mexico and possibly 7,000 species may be found worldwide. Velvet ants range in length from 3/16 to 1 inch (5 to 25 mm). The various species exhibit patterns in a variety of colors, incorporating black, brown, red, orange, yellow, gold, white and silver. The presence of one or more bright colors on velvet ants is considered to be aposematic coloration, serving to warn off would-be predators. Velvet ants have a very short pedicel that lacks a node (upward projection), which helps distinguish them from true ants (Formicidae). The pedicel is so short that the teardrop-shaped gaster appears to abut the mesosoma (thorax plus the first abdominal segment). The exoskeleton of velvet ants is exceptionally thick and puncture-resistant. 

The so-called cow killer, or eastern velvet ant (Dasymutilla occidentalis), is arguably the most reported and recognizable velvet ant among pest professionals. This 2/3 to 3/4 inch (15 to 20 mm) long species, with striking red and black coloration, occurs in most of the continental U.S. except for some of the northernmost states and portions of the Southwest. Figure 1 shows the wingless female and winged male of D. occidentalis.

Timulla dubitata (Figure 2) and the four-spotted velvet ant (Dasymutilla quadriguttata) (Figure 3) are typical of most North American female velvet ants with respect to exhibiting a smaller (3/16 to 1/2 inch) size range and two to three (usually vivid and contrasting) colors comprising the body patterning.

The thistledown velvet ant (Dasymutilla gloriosa) occurs in the arid Southwest and gets its name from the exceptionally long white setae rising tuft-like from the reddish brown cuticle over most of its 1/2 inch long body (Figure 4). Another southwest species, Dasymutilla klugii, has a black head and thorax and a mostly bright red abdomen (Figure 5).