Found in Canada and the United States (Eastern States): from Texas and Florida in the south of the range to Ontario and Quebec in the north. Found in a variety of environmental conditions: in forests, prairies, pastures, city parks and gardens. Formica pallidefulva is absent in swamps and wet meadows, where it is replaced by species of F. biophilica (in the south of the range) and F. montana , F. glacialis, and others (in the north) [1] [2] .
Morphology
Ants are yellowish-brown, shiny. The length of the workers' head (HL) is 1.16–1.68 mm, the width of the head (HW) is 0.93–1.43, the length of the scape of the antennae (SL) is 1.21—1.90 (the scape is long, curved back over trailing edge of the head), head index (CI) 76–88, scape index (SI) 126–153, total length of workers (TL) 5–6 mm, females 8–10 mm. Unlike similar species, pupae of F. pallidefulva workers often lack an outer cocoon . For the first time this feature was noticed in 1904 by the American Mirmecologist William Morton Wheeler , exploring the populations of F. pallidefulva and Formica incerta in Connecticut , and later in Michigan the entomologist M. Talbot [3] noted, and in Missouri the Mirmecologist J. Treger. In some colonies of F. pallidefulva , cocoons are also absent in male pupae, but female pupae are almost always enclosed in a cocoon [1] .
Anthills
The nests are small, in the soil, in the ground leafy layer, under the bark, under small fallen branches and trunks of trees (less than 10 cm in diameter). Less often build small nesting mounds [1] .
Biology
Small families (several hundred individuals). Winged sex specimens (females and males) occur from April (Florida, USA) to July (Canada) [1] . They feed on insects, floral nectar and the paddy that has fallen on the leaves (but do not plant or protect aphids). The wasp of Aphilanthops frigidus hunts winged males and females of F. pallidefulva [4] . On the lawns and in the gardens of St. Louis ( Missouri ), F. pallidefulva from all local ants is one of the most sensitive to the invasive ant Tetramorium tsushimae introduced into these places [5] . However, throughout many places in the southeastern United States, F. pallidefulva ants often coexist with low density populations of fire ants, Solenopsis invicta Buren , Solenopsis richteri Forel, and populations of hybrid Solenopsis richteri × invicta [1] [2] .
Formica pallidefulva are used as slaves by ants “ slave owners ” of the genus Polyergus ( Polyergus montivagus ) and Formica pergandei (subgenus Raptiformica ). These ants raid the nests of F. pallidefulva and capture pupae there, transferring them to their anthills to grow their “slaves” from them. However, such a type of slave owners as Formica rubicunda Emery , uses F. pallidefulva only as victims, and uses another species for slavery ( Formica subsericea ) [1] [2] [6] .
Serves as a host for the ectoparasite fungus Laboulbenia formicarum ( Labulbeniomycetes ) [7] .
The species was first described in 1802 by the French entomologist Pierre Andre Latreille ( PA Latreille ) under the original name Formica pallide-fulva Latreille , 1802 [8] . Previously belonged to the subgenus Neoformica , which was considered a typical taxon [9] . Included in the species group Formica pallidefulva group, endemic to the Nearctic. It differs from related species ( Formica dolosa , Formica archboldi , Formica incerta , Formica biophilica ) by the absence of distant hairs on the dorsal part of the chest. Formica pallidefulva is considered synonymous with the taxon Formica schaufussi Mayr, 1866 [10] , which was previously considered either a separate species or its subspecies [11] [12] . In 1950, F. schaufussi was restored to an independent species status [13] , and in 2007 reduced to synonyms with F. pallidefulva during the audit of the species group [1] .
The specific name pallidefulva (“pale reddish yellow”) was suggested by Pierre Andre Latreille and created from the Latin adjectives pallidus (“pale”) and fulvus (“dark yellow”, “reddish yellow”). It accurately describes the southern, lighter populations of this species. The northeastern, mid-western and western mountain populations of this species, however, have a darker, black-coffee-brown color, but even in these places, many individuals and whole families have a two-color color, and some may have a color closer to that of southern populations [1] .
