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Genus Formica (Subfamily Formicinae) - Online Catalog of Ants of North America

Genus Formica (Formicinae)






exsecta species group (Genus Formica)




Formica exsectoides Forel. A large aggregation of mounds of this species may occur in a single locality. It sometimes damages bark and cambium of small trees and shrubs. Host: Formica fusca L. Locally called the Allegheny mound ant (Smith, D.R. 1979: 1456).



Formica opaciventris Emery. This ant may construct either earthen mounds or thatched nests (Smith, D.R. 1979: 1456).



Formica ulkei Emery. This is a water and sun loving ant. Mounds are found on forest edges or clearings but never within forests. The mounds are situated to receive direct sunlight much of the day (Dreyer & Park, 1932). The large mounds occasionally have a thin layer of plant debris on their surfaces (Smith, D.R. 1979: 1456). It is most commonly found near water, and a mound must have close proximity to shrubs and trees occupied by homopterans (Talbot, 1961. Ecology 42: 202). Colony founding is primarily by budding (Scherba, 1958. Insectes Soc. 5: 201-213). Rarely, mixed colonies of F. fusca and ulkei are found (Creighton, 1934: 199; Talbot, 1961. Ecology 24: 203) providing evidence that temporary social parasitism is an alternate method of colony formation. As with exsectoides, trunk trails and mass recruitment are employed for the tending of homopterans (Deslippe & Savolainen, 1995). For over 20 years a group of 400 mounds in Palos Park, Illinois was studied by University of Chicago researchers (Holmquist, 1928. Ecology 9; Dreyer & Park, 1932; Dreyer, 1942; Scherba, 1958. Insectes Soc. 5). This is one of the few long term studies of an ant population, and its changes over time.



fusca species group (Genus Formica)




Formica accreta Francoeur.


Formica aerata Francoeur. This ant is found in sandy soil where it nests under rocks.



Formica altipetens Wheeler. Nests are in forested and open areas in the soil; low mounds are sometimes built, but nests are also under objects (Smith, D.R. 1979: 1452).



Formica argentea Wheeler. This ant is found in open or semiopen situations usually in sandy soil under rocks or with a low mound (Smith, D.R. 1979: 1452).



Formica canadensis Santschi. Nests are in open or wooded areas in the soil, sometimes with a low mound. This species has been confused with lepida in much of the literature (Smith, D.R. 1979: 1452).



Formica foreliana Wheeler.


Formica francoeuri Bolton. This ant is most common at low elevations in the Coastal Range and San Bernadino Mountains. It makes crater or mound nests in sandy soil, sometimes under rocks (Smith, D.R. 1979: 1455).



Formica fuliginothorax Blacker. This ant was found in short turf or crumbling banks.


Formica fusca Linnaeus. Nests are found in a wide variety of situations, in forests or open areas, under rocks, logs, in soil, or in rotting wood. Two forms are recognized by Francoeur (1973), form subaenescem which is mostly eastern and form marcida which is mostly western in distribution (Smith, D.R. 1979: 1452).



Formica glacialis Wheeler. This ant is found in woods or open fields where it builds its nests in the soil and with a low mound commonly covered with grass. This species has been confused with F. fusca L. in much of the literature (Smith, D.R. 1979: 1453).



Formica gnava Buckley. Formica gnava is one of the few members of the genus that are found in desert and semi-desert areas. It can also be found in open woods in the mountains. It nests in the soil, normally under rocks (Smith, D.R. 1979: 1453). This species is enslaved by Polyergus breviceps at the study site of Howard Topoff in southwestern Arizona. As a result, it has been a subject of long term studies especially in its relationship to P. breviceps.



Formica hewitti Wheeler. This ant is found in open or semiopen woods and forests where it nests in the soil under rocks or in rotting wood (Smith, D.R. 1979: 1453).



Formica lepida Wheeler.


Formica longipilosa Francoeur.


Formica microphthalma Francoeur. Found in the mountains, this ant may construct small crater nests in the soil (Smith, D.R. 1979: 1453).



Formica moki Wheeler. Nests are in soil under rocks. The nest is unmarked and the entrance is usually a hole near a bush or tree. Francoeur (1973) chose to use the name occidua for this species because occidua has been used more in the literature; however, the case has not been referred to the Commission (Smith, D.R. 1979: 1453). Formerly placed in species group pallidefulva.