Natural History: Also relatively common and well-known, the habits of N. opacithorax are quite similar to those of N. nigrescens. Males are bicolored, black with a reddish-brown gaster, and may be seen flying on calm, cool, sunny, late summer or early fall days.
Taxonomic history
Wheeler & Long, 1901 PDF: 163, 173 (m.q., respectively); Wheeler & Wheeler, 1984a PDF: 273 (l.).Combination in Eciton (Neivamyrmex): Smith, 1942c PDF: 555.Combination in Neivamyrmex: Borgmeier, 1953 PDF: 5.Subspecies of Neivamyrmex californicus: Emery, 1895d PDF: 259; Pergande, 1896 PDF: 874.Status as species: Emery, 1900e: 186; Wheeler & Long, 1901 PDF: 163; Wheeler, 1904f PDF: 300; Wheeler, 1908h PDF: 411; Emery, 1910b PDF: 25; Wheeler, 1910a PDF: 562; Wheeler, 1913d PDF: 113; Smith, 1930a PDF: 2; Wheeler, 1932a PDF: 2; Smith, 1938b PDF: 158; Smith, 1942c PDF: 555 (redescription); Buren, 1944a PDF: 280; Creighton, 1950a PDF: 74; Smith, 1951c PDF: 781; Cole, 1953d: 84; Borgmeier, 1955 PDF: 502 (redescription); Smith, 1958c PDF: 109; Carter, 1962a PDF: 6 (in list); Smith, 1967a PDF: 345; Watkins, 1971 PDF: 94 (in key); Kempf, 1972b PDF: 157; Watkins, 1972 PDF: 349 (in key); Hunt & Snelling, 1975 PDF: 21; Watkins, 1976 PDF: 16 (in key); Smith, 1979: 1332; Watkins, 1982 PDF: 211 (in key); Watkins, 1985 PDF: 482 (in key); Wheeler & Wheeler, 1986g PDF: 19 (in key); MacKay et al., 1988: 87; Deyrup et al., 1989 PDF: 94; Wheeler & Wheeler, 1990a PDF: 461; Bolton, 1995b: 290; Ward, 1999a PDF: 90 (in key); Mackay & Mackay, 2002 PDF: 62; Deyrup, 2003 PDF: 45; MacGown & Forster, 2005 PDF: 67; Ward, 2005 PDF: 62; Snelling & Snelling, 2007 PDF: 487; Branstetter & Sáenz, 2012 PDF: 254; Deyrup, 2017: 38.Senior synonym of Neivamyrmex opacithorax castaneum: Borgmeier, 1955 PDF: 502; Smith, 1958c PDF: 109; Kempf, 1972b PDF: 157; Smith, 1979: 1332; Bolton, 1995b: 290; Snelling & Snelling, 2007 PDF: 487.Figures 108, 109, 120, 134, 145
Eciton (Acamatus) californicum subsp. opacithorax Emery , 1894: 184 (w, in key). U. S. A. , Missouri , Doniphan ( MHNG ). Emery, 1895 b: 259. Pergande, 1895: 874. Forel, 1899: 28 .
Eciton (Acamatus) opacithorax : Emery, 1900 a: 524; Emery, 1910: 25. Wheeler & Long, 1901: 163, 173 (w, q). Wheeler, 1908 b: 411 (m). M. R. Smith, 1924: 84. Mallis, 1941: 62.
Eciton (Acamatus) carolinense : Wheeler, 1921: 314 (q). Misidentification
Eciton (Neivamyrmex) opacithorax : M. R. Smith, 1932: 555 (w, q, m). M. R. Smith, 1951 [in Muesebeck, et al.]: 781. Buren, 1944: 180. Creighton, 1950: 74.
Eciton (Acamatus) opacithorax var. castaneum Borgmeier , 1939 a: 416 (w). COSTA RICA , San Jose ( MCSN ) .
Eciton (Acamatus) californicum : Mallis, 1941: 62 (w). Misidentification
Eciton (Neivamyrmex) californicum : M. R. Smith, 1942: 560 (w). Misidentification
Eciton (Neivamyrmex) opacithorax subsp. castaneum : Borgmeier, 1948: 191 (w, q m). COSTA RICA, San Jose.
Neivamyrmex opacithorax : Borgmeier, 1953: 6. Watkins, 1972: 349; Watkins, 1976: 16, 22. Watkins, 1985: 482, 484.
DISTRIBUTION (Map 10)
UNITED STATES: Virginia and Tennessee, south to Florida, west to California; MEXICO (Baja California, Jalisco); GUATEMALA; COSTA RICA. SPECIMENS EXAMINED
We have 51 records from within the United States.
DISCUSSION
Although N. opacithorax is a widespread species it is not as commonly encountered as other members of the N. nigrescens group. Within the group it is readily recognized by the distinctively shaped mandible and the shiny head. It is presumably a raider on other ant species. Workers of this species were discovered during the processing of a number twig cuttings which contained a colony of Pseudomyrmex championi (Forel) in Guatemala. It is unknown if the Neivamyrmex were actively entering the colony while it was intact or if the raiding began as the twigs were cut and collected for processing (P. S. Ward, pers. comm.).
Automontage images of N. opacithorax may be viewed at antweb. org.
Neivamyrmex opacithorax is a species of army ant in the family Formicidae.[1][2][3][4]
Neivamyrmex opacithorax is a species of army ant in the family Formicidae.
