fusca-group field ants

(Formica fusca group)

fusca-group field ant (Formica fusca group)
Photo by Alfredo Colon

The genus Formica has been divided by taxonomists into thirteen species groups based on distinctive features and behavior that can be easily seen in the field. The most diverse and most abundant of these is the fusca group. There are 45 species in the fusca group worldwide, 21 species in North America north of Mexico, and at least 8 species in Minnesota. These species were formerly in the subgenus Serviformica. That subgenus is not valid because it does not contain all of the descendants of one common ancestor and no others (monophyletic). It is not used in North America, where it is considered a junior synonym of Formica, but it is still used in Europe.


Most fusca-group field ants are found in grasslands and open woodlands. Some occur in closed canopy forests, in bogs, or in fens.

Fusca-group field ants are often the unwitting hosts of slave makers, including Amazon ants (Polyergus spp.) and slave-raider field ants (Formica sanguinea group), or of temporary social parasites in the rufa-group wood ants (Formica rufa group).


All fusca-group field ants have one or two offset teeth on the jaws (mandibles) at the base, the part closest to the head. Most are uniformly dark colored, black or dark brown. Some are reddish or yellowish on the front part of the body (mesosoma), sometimes also on the head around the mouthparts.


Distribution Map



24, 27, 29, 30, 82.



Hymenoptera (ants, bees, wasps, and sawflies)  


Apocrita (narrow-waisted wasps, ants, and bees)  


Aculeata (ants, bees, and stinging wasps)  


Formicoidea (ants)  


Formicidae (ants)  




Formicini (wood, mound, field ants, and allies)  


Formica (wood, mound, and field ants)  

Subordinate Taxa


ant (Formica albipennis)

ant (Formica browni)

ant (Formica candida)

ant (Formica cinereofusca)

ant (Formica foreliana)

ant (Formica gerardi)

ant (Formica glauca)

ant (Formica gnava)

ant (Formica hayashi)

ant (Formica kozlovi)

ant (Formica lemani)

ant (Formica lepida)

ant (Formica longipilosa)

ant (Formica microphthalma)

ant (Formica moki)

ant (Formica occulta)

ant (Formica pachucana)

ant (Formica propatula)

ant (Formica pulla)

ant (Formica retecta)

ant (Formica sibylla)

ant (Formica subcyanea)

ant (Formica subelongata)

ant (Formica yoshiokae)

black bog ant (Formica picea)

bright mound ant (Formica neoclara)

Canada mound ant (Formica canadensis)

dry mound ant (Formica xerophila)

Francoeur’s field ant (Formica francoeuri)

gray mound ant (Formica aerata)

Hewitt's mound ant (Formica hewitti)

high mound ant (Formica altipetens)

icy mound ant (Formica glacialis)

impolite mound ant (Formica subpolita)

Japanese wood ant (Formica japonica)

jet black mound ant (Formica gagatoides)

light bronze mound ant (Formica subaenescens)

New World red bearded field ant (Formica neorufibarbis)

overgrown mound ant (Formica accreta)

Pacific field ant (Formica pacifica)

podzol mound ant (Formica podzolica)

prairie mound ant (Formica montana)

silky mound ant (Formica fusca)

silvery field ant (Formica argentea)

somewhat silky mound ant (Formica subsericea)

transmountain mound ant (Formica transmontanis)






Common Names


fusca group

fusca-group field ants












The bulbous part of the abdomen of ants, bees, and wasps. In ants it usually begins at segment three.



In Hymenoptera: the front part of the body, consisting of all three segments of the thorax and the first segment of the abdomen, to which the wings are attached.






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Alfredo Colon

    fusca-group field ant (Formica fusca group)      
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  Alfredo Colon

Location: Woodbury, MN

fusca-group field ant (Formica fusca group)

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Created: 8/6/2023

Last Updated:

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