Neivamyrmex californicus

Snelling and Snelling (2007) - This species appears to be primarily an ant of montane and foothill areas. Little is known about the feeding preferences of this species other than that it presumably attacks exclusively, or nearly so, other ant species. Ward (1999) lists the following as prey species of this ant: Messor andrei, Solenopsis molesta, Pheidole californica and Pheidole hyatti. One of us (GCS) observed a portion of a raid on a Solenopsis xyloni colony; the raid was well underway when it was discovered. It was apparently a violent one with S. xyloni vigorously defending its nest. Whether or not the raid was successful from the standpoint of N. californicus is unknown but the ground was littered with dead and dying of both species. The wingless phorid fly, Xanionotum hystrix Brues (Diptera: Phoridae), has been associated with a colony of N. californicus collected in San Diego County, California (J. H. Hunt, pers. comm.).

Identification
Key to the Neivamyrmex species of the United States

Distribution
United States: California. Mexico: Baja California.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Castes
The male caste is unknown.

Nomenclature

 *  californicus. Eciton californicum Mayr, 1870b: 969 (w.) U.S.A. Watkins, 1972: 364 (q.). Combination in E. (Acamatus): Emery, 1894c: 182 (in text); in E. (Neivamyrmex): Smith, M.R. 1942c: 560; in Neivamyrmex: Borgmeier, 1953: 8. Senior synonym of obscura: Borgmeier, 1955: 517. See also: Ward, 1999a: 76; Snelling, G.C. & Snelling, R.R., 2007: 467.
 * obscura. Eciton (Acamatus) californicum var. obscura Forel, 1914d: 265 (w.) U.S.A. [Unresolved junior primary homonym of obscurum Forel, above.] Junior synonym of californicus: Borgmeier, 1955: 517.

Determination Clarifications
All previous out of state records (beyond California) believed to apply to this species have proven to refer to the recently recognized shiny headed form of Neivamyrmex nigrescens (Ward 1999). Watkins (1972) described what he believed was the queen of N. californicus, however recent reexamination of the specimen in question (Ward, 1999) has led to the conclusion that it too is a representative of the shiny form of N. nigrescens. (Snelling and Snelling 2007)