Dasymutilla vestita

Dasymutilla vestita (Lepeletier, 1845)

Mutilla vestita Lepeletier, 1845: 634, ♀.

Mutilla Montezumae (sic) Lepeletier, 1845: 634, ♀.

Mutilla fulvohirta Cresson, 1865: 433, ♁.

Dasymutilla zelaya (Blake): Fox 1899: 244, ♀ nec. ♁.

Sphaerophthalma (sic) townsendi Cockerell, 1894: 199, ♁.

Sphaerophthalma (sic) aspasia Cameron, 1895: 370, ♁.

Mutilla aspasioides Dalla Torre, 1897:12. Replacement name for Mutilla aspasia (Cameron).

Ephuta californica var. euchroa Cockerell, 1897: 513, ♀.

Dasymutilla homole Mickel, 1928: 75, ♀. New synonym.

Dasymutilla vandala Mickel, 1928: 74, ♁. New synonym.

Dasymutilla cotulla Mickel, 1928: 75, ♁. New synonym.

Material examined. I examined 26 males of D. cotulla (CASC, CNCI, FSCA, UCDC, UMSP), 15 females of D. homole (CSCA, FSCA, UCDC, UMSP), six males of D. vandala (CASC, CNCI, CSCA, UCDC, UMSP), 116 females of D. zelaya (CASC, CNCI, CSCA, FSCA, UMSP) and over 1050 specimens of D. vestita (AMNH, CASC, CNCI, CSCA, EMEC, EMUS, FMNH, FSCA, NVDA, OSUC, PMNH, UCDC, UCRC, UMMZ, UMSP).

Distribution. Canada (Alberta, Saskatchewan), Mexico (Aguascalientes, Chihuahua, Coahuila, Durango, Nuevo Leon, Oaxaca, Veracruz and Zacatecas) and USA (Arizona, Arkansas, California, Colorado, Idaho, Kansas, Montana, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington and Wyoming).

Remarks. As discussed above in the remarks for D. gorgon, the females formerly associated with D. zelaya are remarkably similar to D. vestita, differing only in mesosomal setal color. As seen in males of D. gloriosa, species formerly separated by mesosomal setal color can be recognized as synonymous after discovery of intermediate forms (Figs 11–14). Females formerly called D. zelaya from Arizona frequently have minor traces of the reddish mesosomal setae that are diagnostic for D. vestita. Additionally, these females have often been collected in the same localities as males that are typical of D. vestita. Dasymutilla cotulla is structurally identical to males of D. vestita, differing from that species by mesosomal setal color only (dorsally black in D. cotulla and dorsally yellow to red in D. vestita). Females formerly associated with D. zelaya (now considered members of D. vestita) have been regularly collected in the same localities as D. cotulla. Overlapping distribution and morphological similarity reveal they are conspecific. Dasymutilla vandala is identical to D. cotulla, except for the seta-filled pit on S2 (distinct in D. cotulla and apparently absent in D. vandala). The holotype of D. vandala, however, does have a faint indentation of a seta-filled pit with a few scattered setae. The size and distinctiveness of the S2 pit are variable in western populations of D. vestita. Additionally, conspecific populations of D. bioculata (Cresson, 1865) show even more extreme variation in the sternal setal pit than seen between D. cotulla and D. vandala (Williams et al. 2010). For these reasons, D. cotulla and D. vandala are recognized as junior synonyms of D. vestita.

Dasymutilla homole, known only from females in southern New Mexico, is structurally identical to other females of D. vestita. The only difference between these species is that D. homole has the apical tergites covered with black setae, rather than uniformly yellow to red, like typical D. vestita. In the northwestern Chihuahuan Desert in New Mexico and Texas, the extent of this black setae varies; some individuals have the T3–5 setae entirely black, some orange mesally and some mostly orange with few black setae laterally. This appears to be a gradient, rather than discrete species-level difference and this extent of color variation has been observed in other Dasymutilla species, such as D. bioculata (Williams et al. 2010). Dasymutilla homole syn. nov., is therefore recognized as a synonymous color variant of D. vestita.

Dasymutilla vestita is one of the most common and widespread velvet ant species in North America and, until recently, it bore a similar name to another common and widespread species, D. ursus (Fabricius, 1793). Dasymutilla ursus was formerly called D. vesta (Cresson, 1865) until a senior synonym was recognized (Brothers et al. 2022). Although this change will require many curatorial changes, there are a few cosmetic upsides. First, the epithet vestita could easily be mis-translated as “small vesta ”, but D. vestita is almost always larger in size than D. ursus. Second, D. vestita and D. ursus are not closely related, so their similar names used to be somewhat misleading.