Formica pacifica is a brightly coloured, aggressive species of Formica occupying the west coast of the United States and Canada. This species is a host for the temporary social parasite Formica obscuripes, and potentially more temporarily parasitic and slave raiding Formica species (J. Roth, pers. comm., 2019).
- 1 Identification
- 2 Distribution
- 3 Biology
- 4 Castes
- 5 Nomenclature
- 6 References
Keys including this Species
- Key to Nearctic Formica fusca group males
- Key to Nearctic Formica fusca group queens
- Key to Nearctic Formica fusca group workers
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Alate brood is produced after hibernation, and, in British Columbia, nuptial flights occur from July to the middle of September (on particularly warm days). Male sexuals are released first, in the early afternoon. Female alates fly soon after. Dealate queens often overwinter before laying their first eggs.
Unlike most species from the F. fusca group, Formica pacifica colonies prefer their nests moderately dry. Pupae are stored at the top of the nest, often underneath a rock or another solid surface. Larvae and eggs are usually stored deeper underground, in the additionally moistened parts of the nest.
Formica pacifica collects honeydew. These ants are also scavengers, primarily collecting dead arthropods. Dead, dried out worms are collected in particularly high numbers. Foraging activity primarily occurs in the daytime, with the peak amount of workers dispatched in the afternoon. These ants generally forage alone, but will form trails to plants containing aphids. Once food is found, workers will often recruit others to help feed, or pull food back to the nest.
Association with Other Organisms
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- pacifica. Formica pacifica Francoeur, 1973: 131, figs. 190-197 (w.q.) U.S.A.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
- Bolton, B. 1995b. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 200, catalogue)
- Francoeur, A. 1973. Révision taxonomique des espèces néarctiques du groupe fusca, genre Formica (Formicidae, Hymenoptera). Mém. Soc. Entomol. Qué. 3: 1-316 (page 131, figs. 190-197 worker, queen described)