Neivamyrmex opacithorax (Emery) ^HNS

Figures 108, 109, 120, 134, 145

Eciton (Acamatus) californicum subsp. opacithorax Emery ^HNS, 1894: 184 (w, in key). U. S. A., Missouri, Doniphan (MHNG). Emery, 1895 b: 259. Pergande, 1895: 874. Forel, 1899: 28 .

Eciton (Acamatus) opacithorax ^HNS: 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 ^HNS: Wheeler, 1921: 314 (q). Misidentification

Eciton (Neivamyrmex) opacithorax ^HNS: 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 ^HNS, 1939 a: 416 (w). COSTA RICA, San Jose (MCSN) .

Eciton (Acamatus) californicum ^HNS: Mallis, 1941: 62 (w). Misidentification

Eciton (Neivamyrmex) californicum ^HNS: M. R. Smith, 1942: 560 (w). Misidentification

Eciton (Neivamyrmex) opacithorax subsp. castaneum ^HNS: Borgmeier, 1948: 191 (w, q m). COSTA RICA, San Jose.

Neivamyrmex opacithorax ^HNS: 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 ^HNS is a widespread species it is not as commonly encountered as other members of the N. nigrescens ^HNS 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) ^HNS in Guatemala. It is unknown if the Neivamyrmex ^HNS 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 ^HNS may be viewed at antweb. org.