Aphaenogaster occidentalis ( Emery, 1895 )

Shattuck, Steve & Cover, Stefan, 2016, Taxonomy of some little-understood North American ants (Hymenoptera: Formicidae), Zootaxa 4175 (1), pp. 10-22 : 13-14

publication ID

https://doi.org/ 10.11646/zootaxa.4175.1.2

publication LSID

lsid:zoobank.org:pub:011B74BE-40C0-4606-9354-C637F83C3E43

DOI

https://doi.org/10.5281/zenodo.6062948

persistent identifier

https://treatment.plazi.org/id/03E5E90B-FF8B-233C-FF3C-98E6FAE5718C

treatment provided by

Plazi

scientific name

Aphaenogaster occidentalis ( Emery, 1895 )
status

 

Aphaenogaster occidentalis ( Emery, 1895) View in CoL

Stenamma (Aphaenogaster) subterraneum occidentale Emery, 1895: 301 . Syntype or holotype worker(s), Pullman , Washington [46°44′N 117°11′W] GoogleMaps , United States (T. Pergande) (probably Museo Civico di Storia Naturale, Genoa, not seen) [types of junior synonym A. subterranea borealis Wheeler, W.M. 1915 examined: 13 syntype workers, Lardeau (as Lardo), Kootenay Lake , British Columbia [50°09′N 116°57′W] GoogleMaps , Canada (J.C. Bradley) (Museum of Comparative Zoology) [http://www.antwiki.org/wiki/ Aphaenogaster View in CoL _ occidentalis View in CoL ]].

Aphaenogaster subterranea valida Wheeler, W.M., 1915: 411 View in CoL . Worker, queen and male syntypes, North Cheyenne Cañon, near Colorado Springs [38°48′N 104°53′W], Colorado (W.M. Wheeler) (Museum of Comparative Zoology) [http://mczbase.mcz.harvard.edu/guid/MCZ:Ent:20609].

Creighton (1950) considered A. occidentalis and A. valida to be geographic “races” of A. subterranea , the former occurring from California and Nevada northward through Oregon and Washington and into British Columbia while the latter occurred from Colorado and Wyoming northward into Montana and then west into southern British Columbia . He reported a broad area of integration between the two forms, from British Columbia, eastern Washington, northern Idaho and western Montana, where they showed greatly increased variability. He separated the two based on size, A. valida ranging up to 6mm in length while A. occidentalis reaching only 4.5mm, and color, A. valida being “usually castaneous brown” and A. occidentalis “usually piceous brown.” However, he noted that large numbers of workers were required to separate the two forms with certainty and that it was often impossible to identify isolated workers.

Little has changed since Creighton’s study. Examination of recent collections suggests that while western populations do average slightly smaller than eastern populations, there is considerable overlap, making reliable separation impossible. Color shows a similar pattern with geographic differentiation but considerable overlap. It seems apparent that these two forms are variants of a single variable species. We therefore consider A. subterranea valida Wheeler to be a junior synonym of A. occidentalis (Emery) .

This species is found from British Columbia south to California and east to Montana and Colorado.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Aphaenogaster

Loc

Aphaenogaster occidentalis ( Emery, 1895 )

Shattuck, Steve & Cover, Stefan 2016
2016
Loc

Aphaenogaster subterranea valida

Wheeler 1915: 411
1915
Loc

Stenamma (Aphaenogaster) subterraneum occidentale

Emery 1895: 301
1895
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