March, 1919] A Key to Wisconsin Ants 287 



F. truncicola integroides Emery. 



The workers of this species pile large quantities of vegetable 

 debris about stumps and logs and make their nests in the 

 stumps and bogs. 



The writers have not seen specimens of this ant from 

 Wisconsin. 



Fusca Group. 



1. Gula with erect hairs. Top of head much darker than the other portions of 



the head cinerea cinerea var. neocinerea. Wheeler. 



Gula without erect hairs. Pubescence on the gaster dense and silky 



fusca var. subsericea Say. 



F. cinerea cinerea var. neocinerea Whir. 



The workers build flattened mounds in the meadows and 

 bogs of the Northwestern States. 



The Junior writer has observed this species attending 

 Pubilia concava on Helianthus sp. It has been observed by the 

 Senior writer to attend A. pomi on apple. 



F. fusca var. subsericea Say. 



This beautiful shining species is one of the most abundant 

 ants in North America. It is very widely distributed through- 

 out the Eastern States. 



The workers are cowardly ants and are made slaves of by 

 ants of the groups sanguinea, riifa and exsecta. Although they 

 feed on insects to a large extent, the workers are also given to 

 attending aphids. 



Nests are built under stones or in low flat mounds in sunny 

 places. Their nests often disfigure beautiful lawns in the 

 Northern States. 



F. subsericea has been observed to attend the following 

 aphids: Chaitophoriis populicola on poplar, C. negundinis on 

 box elder, C. nigrae on Salix fragilis and the membracid, Pubilia. 

 concava on Helianthus sp. 



Subgenus Neoformica. 



1. Erect hairs present on the gula and petiole 2. 



Erect hairs absent on the gula and petiole 3. 



2. Hairs on the gula and petiole numerous and conspicuous 



■ pallide-fulva schaufussi Mayr. 



Hairs on the gula and petiole few, often lacking on one or the other; head, 

 thorax and gaster darker paliide-fulva schaufussi var. incerta Mayr. 



3. Head and thorax brown or reddish brown, gaster shining '. . 



pallide-fulva nitidiventris Emery. 



Head and thorax darker, body often less shining 



pallide-fulva nitidiventris var. fuscata Emerj^ 



