444 ANTS. 



by her own workers or by the intrusive queen. Observation^ on arti- 

 ficial colonies show that the consocians queen treats the ho>t (jueen 

 with indifference, even after she has been confined in the same nest v 

 for over a year, or as if she were one of the workers. Moreover, the 

 inccrta queen displays no inclination to forsake her colony, and no 

 hostilities develop between her and her own workers. I deem it prob- 

 able, therefore, that the parasite instinctively seeks out some impov- 

 erished or queenless colony of the host species. We shall see, however, 

 that this custom is by no means universal among the temporary parasites. 



Other North American Formica of the rufa group known to have 

 diminutive females as small as those of consocians or even smaller are: 

 inicrogyna (Fig. 262), rasilis, nevadensis, impc.va, ncpticula and dako- 

 tensis. As the nesting habit of these is very similar to that of con- 

 socians, and as I have found in Colorado two small mixed nests of 

 dakotcnsis and incerta, I believe that there is little doubt that all these 

 species are temporary social parasites. 



2. Macrogynous Formicae of the Rufa Group. The forms included 

 here are the typical European rufa, with its subspecies, pratcnsis and 

 truncicola, and in America the subspecies obscuriventris, obscurif>cs 

 and Integra, with several varieties, and the species ciliata, crinita, orcas, 

 cotnata and spccnlaris. In several of these forms the stature of 

 the female is somewhat diminished and in ciliata (Fig. 263), crinita, 

 etc., her color, pilosity or sculpturing are aberrant. Small mixed 

 colonies of F. truncicola and fusca have been known for some 

 years. Forel (1874) described one which he found near Loco, 

 Switzerland ; one was found by Zur Strassen in Saxony, and Was- 

 mann (i9Oi-'o2, 1905 d ) has recently found three others in Luxem- 

 burg. These mixed colonies were originally regarded as accidental 

 or abnormal occurrences, but my observations (1904/2, 1906^) indi- 

 cated very clearly that they are merely incipient and transitory stages 

 in the normal life of the truncicola colony and that the queen of 

 this species is a temporary parasite. After observing two of the 

 mixed colonies in artificial nests Wasmann reached the same con- 

 clusion. Recently (1908) Viehmeyer has shown that truncicola females 

 are readily adopted by fusca workers. Now as the North American 

 intcgra and its varieties, Jucmorrhoidalis and coloraclcnsis. closely 

 resemble the European truncicola in structure and nesting habit, and 

 as I have succeeded in causing a female Integra to be adopted by work- 

 ers of subscricea, there can be little doubt that the huge formicaries of 

 all these rufa forms have their beginnings in temporary parasitism. 

 Finally, the species with rich red or yellow, very glabrous or unusually 



