Neivamyrmex opacithorax (Emery)

Snelling, G. C. & Snelling, R. R., 2007, New synonymy, new species, new keys to Neivamyrmex army ants of the United States., Advances in ant systematics (Hymenoptera: Formicidae): Homage to E. O. Wilson - 50 years of contributions. (Memoirs of the American Entomological Institute 80), pp. 459-550 : 486-487

Neivamyrmex opacithorax (Emery)

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.