Neivamyrmex swainsonii (Shuckard) ^HNS

Figures 15, 25, 30, 46, 73, 122, 136, 147, 149

Labidus swainsonii Shuckard ^HNS, 1840: 201 (m). BRAZIL (BMNH). Westwood, 1842: 76. F. Smith, 1859: 8 (m).

Labidus mexicanus F. Smith ^HNS, 1859: 7 (m). MEXICO, Orizaba (BMNH) (examined). NEW SYNONYMY .

Eciton (Acamatus) nitens ^HNS: Pergande, 1895: 874. Misidentification

Eciton (Acamatus) swainsonii ^HNS: Emery, 1900: 515, 525. Emery, 1910: 27. Santschi, 1916: 370. Santschi, 1931: 74. Gallardo, 1920: 379. Borgmeier, 1923: 50.

Eciton (Acamatus) arizonense Wheeler ^HNS, 1908 c: 414 (m). U. S. A., Arizona, Nogales. (MCZC). Emery 1910: 25. M. R. Smith, 1942: 581 (m)

Eciton (Acamatus) lieselaei ^HNS: Gallardo, 1920: fig. 32. Misidentification

Eciton (Neivamyrmex) swainsoni ^HNS: Borgmeier, 1948 b: 462.

Eciton (Neivamyrmex) arizonense ^HNS: Creighton, 1950: 69 - 70 (m).

Neivamyrmex swainsoni ^HNS: Borgmeier, 1953: 16. Borgmeier, 1955: 454 - 458 (m). Watkins, 1972: 352 (m). Watkins, 1976: 24 (m). Cokendolpher & Francke, 1990: 13.

Eciton (Neivamyrmex) commutatum ^HNS: M. R. Smith, 1942: 568 (misidentification).

Neivamyrmex swainsoni arizonensis ^HNS: Borgmeier, 1953: 19 (m).

Neivamyrmex fallax Borgmeier ^HNS, 1953: 48 (w). U. S. A., Texas, Victoria (USNM). NEW SYNONYMY

DISTRIBUTION (Map 11)

UNITED STATES: Kansas, Louisiana and Texas, west to California; MEXICO: border states south to Chiapas and Yucatan; south to ARGENTINA.

SPECIMENS EXAMINED

We have 123 records for this species in the United States.

DISCUSSION

F. Smith's Labidus mexicanus ^HNS was made a variety of pilosus ^HNS by Borgmeier (1936), a synonym of pilosus ^HNS by M. R. Smith (1942) and, finally, a subspecies of pilosus ^HNS by Borgmeier (1953), where it has remained. We have examined the type of L. mexicanus ^HNS and determined that none of the above decisions was correct. Labidus mexicanus F. Smith ^HNS is, instead, a junior synonym of N. swainsonii ^HNS (New synonymy).

Due to its large size and relative abundance N. swainsonii ^HNS is easily one of North America ’ s most conspicuous army ants. Surprisingly, for many years the worker form of this common and wideranging species was unknown. We have determined that N. fallax ^HNS is the worker of N. swainsonii ^HNS. The evidence for this association is scanty: it is based on a worker of N. fallax ^HNS found attached to the leg of a male collected in Arizona. Although throughout the United States and Mexico the ranges of these two taxa overlap nicely, N. fallax ^HNS is unknown south of Guatemala.

Differences do exist between the North and South American populations; however after having examining the type specimen from Brazil and several other specimens from Central and South America we are forced to conclude that we are dealing with a single wide ranging and slightly variable species.

Automontage images of the male caste may be viewed at antweb. org