Formicinae
Guides
Brachymyrmex
Rover Ants
Brachymyrmex is a genus of minute ants in the subfamily Formicinae, commonly known as rover ants. Workers are distinguished by having only nine antennal segments—fewer than most ants—and by the petiole being concealed by the gaster in dorsal view. The genus contains 44 species and 17 subspecies, though species-level identification is challenging due to minimal morphological variation, small size, and soft-bodied workers. Brachymyrmex patagonicus, the dark rover ant, has become a significant invasive pest in the southern United States and other regions worldwide.
Brachymyrmex brevicornis
Brachymyrmex brevicornis is a species of ant in the family Formicidae, originally described by Emery in 1906. The species is currently recognized as accepted in major taxonomic databases, though some sources list it as a synonym of Brachymyrmex cordemoyi. It belongs to the subfamily Formicinae and tribe Myrmelachistini. The genus Brachymyrmex consists of small, inconspicuous ants commonly known as "rover ants" that are frequently associated with human-modified environments.
Brachymyrmex depilis
Hairless Rover Ant
Brachymyrmex depilis is a North American species of rover ant in the subfamily Formicinae. The species was described by Emery in 1893. A 2019 study synonymized B. nanellus and rejected the subspecies B. depilis flavescens due to lack of significant morphological differences. The common name "Hairless Rover Ant" reflects its relatively glabrous appearance compared to congeners.
Brachymyrmex species-d
Brachymyrmex species-d is an undescribed species within the genus Brachymyrmex, a group of small, inconspicuous ants commonly known as "rover ants." The genus Brachymyrmex contains multiple cryptic species that are difficult to distinguish morphologically, and species-d represents one of several lineages awaiting formal taxonomic description. Like other members of the genus, it is expected to be minute in size and adapted to disturbed habitats, though specific biological details remain undocumented pending formal study.
Camponotini
Camponotine Ants
Camponotini is a species-rich tribe of ants within the subfamily Formicinae, comprising 11 extant and 2 extinct genera with over 2,500 species. The tribe includes the well-known genus Camponotus (carpenter ants), along with Colobopsis, Polyrhachis, and several smaller genera. Members of this tribe are distinguished by their obligate association with the bacterial endosymbiont Blochmannia, which provides nutritional benefits. The tribe originated in the Eocene approximately 38.4 million years ago, likely in Australasia or the Indomalayan region.
Camponotus absquatulator
Camponotus absquatulator is a species of carpenter ant native to California, Nevada, and Baja California. It was formally separated from the Camponotus festinatus species complex in 2006 by myrmecologist Roy Snelling. As a member of the genus Camponotus, it is a large-bodied ant that excavates wood for nesting. The specific epithet "absquatulator" is derived from a humorous pseudo-Latin verb meaning "to abscond" or "to leave hurriedly," reflecting the species' elusive nature or perhaps the taxonomic confusion that preceded its formal description.
Camponotus americanus
American Carpenter Ant
Camponotus americanus is a North American carpenter ant species characterized by its relatively large size among congeners. Workers measure 7–10 mm in length. The species is primarily ground-nesting, though it exhibits flexibility in nest site selection. It belongs to the diverse genus Camponotus, which contains over 1,000 species globally and is notable for its wood-excavating habits and ecological roles as decomposers.
Camponotus clarithorax
Carpenter ant
Camponotus clarithorax is a species of carpenter ant in the subgenus Camponotus, native to western North America. It was described by William Morton Creighton in 1950. The species occurs in California, Oregon, and the Baja California Peninsula, with possible records from the eastern United States. Like other carpenter ants, it nests in wood and exhibits the polymorphic worker caste system typical of the genus.
Camponotus decipiens
Deceptive Carpenter Ant
Camponotus decipiens is a species of carpenter ant native to eastern North America and parts of Mexico. Workers range from 3 to 7.5 mm in length and are characterized by a black gaster. Colonies are typically small, often containing fewer than 100 workers but occasionally reaching several hundred. The specific epithet 'decipiens' derives from Latin, meaning 'deceiving, cheating, or trapping'.
Camponotus fragilis
Camponotus fragilis is a carpenter ant species endemic to the southwestern United States and northern Mexico. First described by Theodore Pergande in 1893, it was synonymized and later revived by Roy Snelling in 2006. The species has been studied for its gut bacterial communities, which show compartmentalization across different gut sections and variation between laboratory-raised and field-collected colonies.
Camponotus modoc
Western Carpenter Ant, Western Black Carpenter Ant
Camponotus modoc, the western carpenter ant, is a large black ant species native to western North America. Workers exhibit polymorphism, ranging from 7 to 13 mm in length, with dark red legs contrasting against a black body. The species constructs nests in dead wood, including forest logs and human structures, and is known for its mutualistic associations with aphids, particularly Cinara occidentalis on white fir. Research demonstrates trail fidelity and colony recognition abilities, with workers returning to specific aphid colonies even after displacement.
carpenter-antwestern-north-americaaphid-mutualismstructural-pestpolymorphismtrail-fidelitychemical-ecologygiant-sequoia-forestforest-ecologyurban-pestCamponotiniFormicinaeHymenopterainvasive-potentialnestmate-recognitionalarm-communicationforaging-ecologyconifer-forestwood-excavationsatellite-colonyCamponotus ocreatus
Carpenter ant
Camponotus ocreatus is a species of carpenter ant in the genus Camponotus, first described by Emery in 1893. It is native to arid and semi-arid regions of northern Mexico and the southwestern United States. Like other members of the genus, it nests in wood and maintains colonies with polymorphic worker castes.
Camponotus schaefferi
Schaeffer's Carpenter Ant
Camponotus schaefferi is a species of carpenter ant in the genus Camponotus, described by Wheeler in 1909. It is native to the southwestern United States and possibly Venezuela. Like other carpenter ants, it excavates wood to create nest galleries rather than consuming wood for nutrition. The species belongs to the diverse subgenus Myrmobrachys, characterized by a relatively low and broad mesosoma.
Camponotus snellingi
Snelling's Carpenter Ant
Camponotus snellingi is a species of carpenter ant named in honor of the myrmecologist Roy R. Snelling. As a member of the genus Camponotus, it shares the characteristic wood-nesting behavior typical of carpenter ants, excavating galleries in dead or decaying wood rather than consuming it. The species was described by Barry Bolton in 1995. Like other Camponotus species, it exhibits polymorphic worker castes with distinct size classes.
Camponotus socius
Sandhill Carpenter Ant
A large carpenter ant native to the southeastern United States, well-adapted to sandy soils of xeric woodlands. Exhibits polymorphic worker castes with distinctive coloration including variegated gaster banding. Notable for ground-nesting behavior unusual among Camponotus species, constructing deep nests with satellite colonies. Activity is primarily crepuscular, with midday retreat during hot periods.
Camponotus ulcerosus
Camponotus ulcerosus is a species of carpenter ant in the genus Camponotus, described by Wheeler in 1910. It is native to the southwestern United States and Mexico. As a member of the carpenter ant group, it nests in wood and exhibits the typical colony structure of the genus with polymorphic workers. Beyond its geographic range and taxonomic placement, specific biological details remain poorly documented in published literature.
Colobopsis
Gate-keeper Ants
Colobopsis is a genus of ants in the subfamily Formicinae, first described by Mayr in 1861 and containing approximately 95 species. The genus is distinguished by pronounced worker caste dimorphism, with major workers possessing phragmotic (truncate, plug-shaped) heads used to block nest entrances. Members of the Colobopsis cylindrica group exhibit autothysis, a defensive behavior where minor workers rupture their gaster to release sticky, irritant mandibular gland secretions. The genus nests primarily in plant material including wood, galls, and dead branches. Colobopsis was historically treated as a subgenus of Camponotus but was restored to full generic status following a 2015 phylogenomic study that identified it as sister to all remaining Camponotini.
Colobopsis etiolata
Pale Gate-keeper Ant
Colobopsis etiolata is a species of ant in the genus Colobopsis, originally described by Wheeler in 1904. It belongs to a genus characterized by specialized defensive castes, including 'doorkeeper' majors with enlarged, plug-shaped heads used to block nest entrances. The species is part of the Colobopsis cylindrica group, which includes the well-known 'exploding ants' that exhibit autothysis (self-sacrificial body rupture) as a defensive mechanism. As a member of this group, C. etiolata likely shares the arboreal, canopy-dwelling habits typical of these Southeast Asian forest ants.
Colobopsis impressa
Common Gate-keeper Ant
Colobopsis impressa is a species of arboreal ant in the subfamily Formicinae, commonly known as the Common Gate-keeper Ant. The species belongs to a genus noted for specialized defensive morphologies, including major workers with plug-shaped heads used to block nest entrances. While detailed species-level studies are limited, the species has been documented across Southeast Asian forests. Its biology appears consistent with the broader Colobopsis cylindrica species group, though specific behavioral observations for C. impressa remain sparse.
Colobopsis mississippiensis
Mississippi Gate-keeper Ant
Colobopsis mississippiensis is a species of ant in the genus Colobopsis, first described by Smith in 1923. It belongs to a group of ants commonly known as "gate-keeper ants" or "doorkeeper ants," characterized by specialized major workers with enlarged, plug-shaped heads used to block nest entrances. The species is native to North America, with records from the Mississippi region implied by its specific epithet. Like other members of the Colobopsis cylindrica group, it exhibits caste polymorphism with distinct worker morphologies adapted for different colony functions.
Colobopsis obliqua
Oblique Gate-keeper Ant
Colobopsis obliqua is a species of ant in the subfamily Formicinae, first described by Smith in 1930. It belongs to a genus known for specialized defensive behaviors, including the 'exploding ant' phenomenon where minor workers rupture their bodies to release toxic secretions. The species is commonly referred to as the 'Oblique Gate-keeper Ant' due to the characteristic head shape of major workers used to block nest entrances.
Colobopsis papago
Colobopsis papago is a species of ant in the genus Colobopsis, family Formicidae. The species was first described by William S. Creighton in 1953. Like other members of the genus, it exhibits the characteristic morphological traits associated with the Colobopsis group, including specialized major workers with modified heads. The species is part of a genus known for diverse defensive strategies, though specific behavioral documentation for C. papago remains limited.
Formica
wood ants, mound ants, field ants
Formica is a large and ecologically significant genus of ants in the subfamily Formicinae, commonly known as wood ants, mound ants, or field ants. The genus includes species with diverse life histories, ranging from free-living colony founders to facultative and obligate social parasites. Many species construct conspicuous earthen mounds that can reach several feet in diameter and height, while others nest in dead wood. Formica ants are notable for their complex social structures, including both single-queen (monogynous) and multiple-queen (polygynous) colonies, with social organization sometimes controlled by supergenes. The genus serves as host for specialized slave-making ants in the genus Polyergus and supports diverse communities of myrmecophilous organisms.
Formica biophilica
Wilson's Field Ant
Formica biophilica is a North American ant species in the genus Formica, described by James Trager in 2007. It belongs to the fusca group within Formica, a diverse assemblage of ants often characterized by their association with open habitats and varied ecological roles. The species epithet 'biophilica' reflects an affinity for living systems or biological environments. Like many Formica species, it participates in complex ecological interactions within its native range, though specific natural history details remain limited in published literature.
Formica densiventris
Compact Mound Ant
Formica densiventris is a North American ant species in the genus Formica, described by Viereck in 1903. It is known by the common name Compact Mound Ant. The species belongs to the subfamily Formicinae and is part of the diverse Formica genus, which includes many socially parasitic and mound-building species. Available information about this species is limited in the provided sources.
Formica dolosa
Wily Field Ant
Formica dolosa is a species of field ant in the genus Formica, family Formicidae. Described by Buren in 1944, this species is part of a large and taxonomically complex genus containing numerous social parasites and free-living species. Like many Formica species, it is likely a generalist in its ecological habits, though specific details of its biology remain limited in the available literature. The species epithet "dolosa" (meaning "wily" or "deceitful") reflects its perceived behavioral characteristics.
Formica fossaceps
Pitted Mound Ant
Formica fossaceps is a species of mound-building ant in the genus Formica, family Formicidae. It was described by Buren in 1942 and is classified within the Formica rufa species group. The common name "Pitted Mound Ant" refers to a distinctive morphological feature of the species. Like other members of the Formicinae subfamily, it is characterized by a single petiole node and the absence of a sting.
Formica glacialis
Icy Mound Ant
Formica glacialis is a cold-adapted ant species in the Formicinae subfamily, described by William Morton Wheeler in 1908. It belongs to the Formica fusca species group and is primarily found in montane and boreal environments of eastern North America. The species is notable for its association with cold, high-elevation habitats, including areas with persistent snow cover.
Formica incerta
Uncertain Field Ant
Formica incerta is a common ant species of eastern North America, often the most abundant Formica in its range. It constructs underground nests with inconspicuous entrance holes and no surface mound. Workers forage diurnally for nectar and honeydew, and the species serves as the primary host for the slave-making ant Polyergus lucidus. First described by Carlo Emery in 1893, its specific epithet reflects historical taxonomic uncertainty and identification challenges.
Formica knighti
Formica knighti is a species of ant in the genus Formica, first described by Buren in 1944. The species belongs to the diverse and ecologically significant genus Formica, which includes many species with complex social behaviors including social parasitism. Like other members of Formica, F. knighti is a social insect living in colonies with a division of labor among workers, queens, and males. Specific natural history details for this species remain limited in published literature.
Formica lasioides
Formica lasioides is a species of ant in the family Formicidae, described by Emery in 1893. It belongs to the large and diverse genus Formica, which includes many species exhibiting complex social behaviors including social parasitism. The species is known from limited verified records, primarily in North America. Like other Formica species, it is likely a ground-nesting ant, though specific natural history details remain poorly documented.
Formica obscuripes
Western Thatching Ant
Formica obscuripes, the western thatching ant, is a North American mound-building ant known for constructing large thatched nests from plant materials. Colonies can contain up to 40,000 workers and demonstrate complex social organization including behavioral constancy in worker task performance. The species employs hybrid foraging strategies combining pheromone-marked columns with visual and path integration navigation. It maintains defensive mutualisms with aphids and exhibits aggressive territorial behavior including the use of formic acid against intruders and competing vegetation.
Formica oregonensis
Oregon Field Ant
Formica oregonensis is a species of ant in the family Formicidae, first described by Cole in 1938. It belongs to the genus Formica, a large and ecologically diverse group of ants found primarily in the Northern Hemisphere. The species is known by the common name Oregon Field Ant. As a member of Formicinae, it lacks a stinger and instead uses formic acid for defense. Beyond basic taxonomic information, specific biological details about this species remain poorly documented in the scientific literature.
Formica podzolica
Podzol Ant
Formica podzolica is a species of mound-building ant in the subfamily Formicinae, described by Francoeur in 1973. The species is associated with podzolic soils and functions as an ecosystem engineer in subalpine and montane environments. Colonies modify soil moisture and nitrogen availability around their nests, creating distinct microhabitats that alter plant community composition and structure.
Formica propinqua
Formica propinqua is a species of ant in the genus Formica, first described by Creighton in 1940. It belongs to the large and diverse Formicinae subfamily, which includes many familiar ant species. The specific epithet 'propinqua' suggests close relationship to other taxa, though detailed natural history information for this species remains limited in available sources.
Formicini
Formicini is a tribe of ants within the subfamily Formicinae, established by Latreille in 1802. The tribe includes approximately 13 extant and 5 extinct genera, with Formica representing the most species-rich genus. Notable members include the slave-making genera Polyergus and Rossomyrmex, which practice dulotic social parasitism by raiding nests of related host species. The tribe exhibits diverse ecological strategies across temperate and arid regions of the Northern Hemisphere.
Lasius
Citronella Ants, Fuzzy Ants, Moisture Ants, Yellow Ants, Lemon Ants
Lasius is a genus of formicine ants comprising approximately 100 species distributed across the Holarctic region. The genus exhibits remarkable ecological diversity, including free-living species, temporary social parasites, and the hyper-social parasite Lasius fuliginosus. Many species are known as "citronella ants" due to their production of citronellal, a lemon-scented defensive compound. Lasius species are significant ecosystem engineers that modify soil properties and engage in mutualistic relationships with root-feeding aphids, herding them for honeydew production.
Lasius americanus
Woodland Fuzzy Ant
Lasius americanus, commonly known as the woodland fuzzy ant, is a small ant species in the subfamily Formicinae. Workers are characterized by dusty brown coloration with lighter semi-translucent legs and a distinctive lack of erect setae on the antennae. The species was historically confused with the Eurasian Lasius alienus and was only recognized as a distinct North American species in 2018. It inhabits temperate forests and woodlands, typically found under rotting wood or in trees.
Lasius crypticus
Cryptic Fuzzy Ant
Lasius crypticus is a species of ant in the genus Lasius, family Formicidae. Described by E. O. Wilson in 1955, this species is part of a diverse and ecologically significant genus of ants commonly known as citronella or fuzzy ants. The specific epithet 'crypticus' suggests cryptic or hidden characteristics, though detailed ecological information remains limited.
Lasius speculiventris
Shiny-bellied Fuzzy Ant
Lasius speculiventris is a species of ant in the genus Lasius, commonly known as the Shiny-bellied Fuzzy Ant. It is found in the northern United States, where it inhabits forests, woodlands, and meadows. As a member of the subfamily Formicinae, it belongs to a diverse group of ants that includes many ecologically important species.
Lasius subumbratus
Less Shady Fuzzy Ant
Lasius subumbratus is a species of ant in the genus Lasius, family Formicidae, described by Viereck in 1903. It belongs to the subfamily Formicinae and tribe Lasiini. The species is known by the common name "Less Shady Fuzzy Ant" and has been documented in citizen science observations.
Myrmecocystus
North American Honeypot Ants, Honeypot Ants
Myrmecocystus is a North American genus of Formicinae ants comprising approximately 30 described species across three subgenera (Myrmecocystus, Endiodioctes, and Eremnocystus). The genus is one of five globally that exhibits the honeypot ant syndrome, in which specialized workers called repletes store large quantities of liquid food in their distended abdomens. These living food reserves sustain colonies during periods of resource scarcity. Molecular phylogenetic studies indicate that none of the three subgenera are monophyletic, suggesting repeated convergent evolution of key morphological and behavioral traits.
Myrmecocystus placodops
Myrmecocystus placodops is a species of honeypot ant native to the southwestern United States and northern Mexico. As a member of the genus Myrmecocystus, it likely exhibits the characteristic replete caste—specialized workers that store liquid food in their distended abdomens. The species was described by Auguste Forel in 1908. Like other honeypot ants, colonies are subterranean and may be targeted by specialized myrmecophilous beetles such as Cremastocheilus scarabs.
Myrmecocystus testaceus
Brick Honeypot Ant
Myrmecocystus testaceus is a nocturnal ant species native to the southern United States, commonly known as the Brick Honeypot Ant. As a member of the genus Myrmecocystus, it possesses the distinctive replete caste—specialized workers that store liquid food in their greatly distended abdomens, serving as living food reserves for the colony. The species nests in sandy soils and has been documented as a host for the myrmecophilous beetle Cremastocheilus.
Myrmecocystus wheeleri
Wheeler's Honeypot Ant
Myrmecocystus wheeleri is a species of honeypot ant native to arid regions of California, Baja California, and Coahuila. Like other members of the genus, it possesses specialized workers called repletes that store liquid carbohydrates in their distended crops for long-term colony sustenance. The species has been documented to host a gut microbiome dominated by halophiles, distinguishing it from congeners that harbor lactic acid and acetic acid bacteria in their replete crops.
Myrmelachistini
Myrmelachistine Ants
Myrmelachistini is a tribe of ants in the subfamily Formicinae, resurrected in 2016 from synonymy under Plagiolepidini. The tribe contains two genera: Brachymyrmex (rover ants) and Myrmelachista. Together these genera comprise at least 50 described species. The tribe is characterized by specific morphological and molecular distinctions that separate it from other formicine tribes.
Nylanderia
Crazy ants
Nylanderia is a large genus of formicine ants with over 130 described species and a nearly cosmopolitan distribution, notably absent from Europe. The genus was resurrected from synonymy with Paratrechina in 2010 based on molecular phylogenetics and morphological reassessment. Species range from small to medium in size (1–4 mm) and exhibit coloration from pale yellow to black. Several species are significant invasive pests, including N. fulva (tawny crazy ant) and N. bourbonica, which form massive supercolonies and cause ecological and economic damage.
Nylanderia austroccidua
Nylanderia austroccidua is a species of ant in the subfamily Formicinae, originally described from a widespread distribution ranging from Utah to Costa Rica. Molecular phylogenetic analysis using Ultraconserved Elements (UCEs) revealed that specimens matching the original description are paraphyletic with respect to Nearctic Nylanderia species, indicating the original concept encompassed multiple cryptic lineages. The species belongs to American Clade I (AC1), a group that includes a Neotropical subclade extending into Mesoamerica. An updated taxonomic description was published in 2024 as part of a revision that described eight new Nylanderia species from the region.
Nylanderia faisonensis
Woodland Crazy Ant
Nylanderia faisonensis is a species of ant in the subfamily Formicinae, commonly known as the Woodland Crazy Ant. It is a member of the genus Nylanderia, which includes several species known for erratic, rapid movement patterns. The species was described by Auguste Forel in 1922. While less studied than its congener the tawny crazy ant (Nylanderia fulva), it shares the characteristic rapid, unpredictable foraging behavior that gives these ants their common name.
Nylanderia flavipes
Yellow-footed Ant
Nylanderia flavipes is a small ant species in the subfamily Formicinae, native to Asia and introduced to the Nearctic region including the United States. It was previously classified under the genus Paratrechina before taxonomic revision. The species serves as a documented host for the parasitoid wasp Gollumiella buffingtoni, with workers showing unusual tolerance and active assistance toward the parasitoid's development. It is one of at least five introduced Nylanderia species established in the Nearctic region.