ADOPTION OF QUEENS BY ALIEN SPECIES. 305 



Aug. 20 8.00 A.M. The same. 

 2.00 P.M. The same. 



Aug. 21 10.30 A.M. The same. The Polyergus queen kept aloof from the in- 

 cerlas all the time until August 24. When I examined the nest at i.OO 

 o'clock on that day the Polyergus 'queen was running around in the nest 

 but avoiding the incertas and they seemed afraid to attack her. About an 

 hour later, however, I found the incerta queen dead and the Polyergus 

 queen standing near her. I removed the dead queen and examined her. 

 I found four cases where her thorax had been punctured by the sharp man- 

 dibles of the Polyergus queen. From that time on the incerta workers not 

 only did not attack the Polyergus queen but they ceased to avoid her, and 

 and on the following day I found one of the workers licking her. Since then 

 they have treated her as they treated their own queen before. There are 

 8 workers in the nest now. 



Besides the experiments with the above mentioned ants I 

 tried a few adoption experiments with queens of F. nepticula, 

 F. sanguined var. rubicunda, and one with a queen of F. difficilis 

 var. consocians. 



The queens of F. nepticula were tried with small colonies of 

 F. inserta, F. fusca var. subcenescens and F. subpolita var. neo- 

 gagates. The two queens that I tried with incerta and subce- 

 nescens gave negative results. The workers attacked the queens 

 fiercely in each case. The active little queen defended herself, 

 however, by seizing them with her mandibles. The movements 

 made the first few minutes were so rapid that the eye could 

 scarcely follow them. In an hour or so, however, the queen 

 was killed in each nest. The behavior was the same when I 

 placed a queen in with a small colony of F. subpolita, but the 

 subpolita workers being smaller than those of the other two species 

 were not able to kill the queen so quickly, and after a fierce 

 struggle of a few minutes she escaped from them. Although she 

 was attacked again from time to time the attacks were not so 

 fierce and several times I saw workers licking her; not only 

 that, but her behavior then became more like what Wheeler has 

 described for the queens of F. consocians when introduced into 

 a colony of F. incerta, more insinuating and conciliatory, and 

 twice I found the nepticula queen feeding a subpolita worker. 

 Although the two queens which I tried with this subpolita colony 

 were both finally killed I think the behavior both on the part of 

 the queen and the workers tends to confirm the conclusions 

 reached by Wheeler in 1906, that F. nepticula is a temporary 

 parasite and that its probable host is F. subpolita. 



