california desert ants

SUBFAMILY ECITONINAE
Genus Neivamyrmex

Neivamyrmex swainsonii (Shuckard)
Figure 47

     Labidus swainsonii Shuckard, 1840:201; _. Westwood, 1842:76. F. Smith, 1859:8; pl. 2 fig. 8; _.
     Eciton (Acamatus) swainsonii: Emery, 1900:515, 525; fig. 22. Emery, 1910:27. Santschi, 1916:370. Santschi, 1931:74. Gallardo, 1920:379; fig. 30. Borgmeier, 1923:50.
     Eciton (Acamatus) arizonense Wheeler, 1908c:414; pl. 26 fig. 5; _. Emery, 1910:25. M. Smith, 1942:581; fig. 19; _.
     Eciton (Acamatus) lieselaei: Gallardo, 1920:fig. 32 (misident.)
     Eciton (Neivamyrmex) swainsoni: Borgmeier, 1948b:462.
     Eciton (Neivamyrmex) arizonense: Creighton, 1950:69-70; _.
     Neivamyrmex swainsoni: Borgmeier, 1953:16. Borgmeier, 1955:454-458; pl. 37 fig. 5-6; pl. 49 fig. 1-2, 7-9, 17-21; _. Watkins, 1972:352; _. Watkins, 1976:24; map 54; pl. 16 fig. 10; pl. 17 fig. 17-19; pl. 20 fig. 8-9; _. Cokendolpher and Francke, 1990:13. Snelling and Snelling 199-------------
     Neivamyrmex swainsoni arizonensis: Borgmeier, 1953:19; _.
     Neivamyrmex fallax Borgmeier 1953:48; figs. 31, 33; o. Add Watkins records-------------------------------
     RANGE: Rio Grande Valley of Texas west to southeastern California; south to Argentina.

     DESERT RECORDS. Map 12. Imperial Co.: Bard, 11 July 1966 (Ratcliff; CDFA); Winterhaven, 4 Aug. 1961 (Maxwell; CDFA); Holtville, 7 Aug 1961 (Curran; CDFA); same locality, 11 Sept. 1959 (C. R. Waegner; CDFA); Calexico, 22 June 1957 (E. I. Schlinger; UCD). Riverside Co.: Blythe, various dates and collectors (CDFA, LACM, UCB).San Bernardino Co.: Vidal Jct., 4 Sept 1947 [G. H. & J. L. Sperry; Borgmeier, 1955].

     DISCUSSION. Surprisingly, for many years the worker form of this common and wide ranging species was unknown. Recent study indicates that N. fallax is the worker of N. swainsonii. Although throughout the United States and Mexico the ranges of these two taxa overlap nicely, N. fallax is unknown south of Guatemala and it is possible that the current concept of N. swainsonii actually includes more than one species. Differences do exist between the North and South American populations; a modern study of this problem might recognize at least two distinct forms.
     Our records are all from lower elevation desert, -13' to 800', in areas of Wash Woodland, Alkali Sink and Saltbush Scrub.