ADOPTION OF QUEENS BY ALIEN SPECIES. 293 



B. 22d. 



August 18. I placed an obscuriventris queen in a Petri dish with eight workers and 

 some pupae of F. subsericea. The workers at first attacked her and continued 

 doing so at intervals until noon the next day. After that they did not 

 attack her, but tolerated her presence in the nest and she remained standing 

 by herself until noon August 23. After that she stayed with the workers 

 all the time and was treated as their own queen. 



B. 220. 



August 19. I placed an obscurivenlris queen in a Petri dish with eight workers and 

 twelve pupae of F. subsericea. She was attacked at first just as the others 

 were and the workers remained hostile until about the middle of the following 

 day when they became indifferent to her presence and by August 25 they 

 adopted her and treated her as their own queen. She had received an injury 

 however in the first attacks from which she did not recover and by the 

 morning of August 27 was dead. There were then six workers in the nest and 

 one of them seemed weak. I removed the dead queen and placed in another. 

 I did not see her attacked after the first day and by a day or two later she 

 was fully adopted by the five workers, the other one having died. 



B. 22d. 



August 24. I placed an obscuriventris queen in a nest containing about fifty 

 workers, one male and many naked pupae of F. subsericea. She was vigor- 

 ously attacked, but within five minutes after she was placed in, while four 

 workers were holding her, two others were diligently licking her thorax and 

 abdomen. There were too many hostile workers in the nest however and 

 by the following morning she had been killed and beheaded. 



B. 226. 



August 29 4.00 P.M. I placed an obscuriventris queen in a Petri dish with 

 ten workers and eight pupae of F. subsericea. She was attacked by the 

 workers that afternoon, but on the following morning was standing by her- 

 self on the opposite side of the dish from where the subsericea were with 

 their pupae, and remained thus for two days. On the third day I disturbed 

 the nest a little, and she moved over and mingled with the workers. They 

 did not attack her and from then on, she stayed with them most of the time 

 and is now, September 10, fully adopted. 



It will be seen in the above experiments that of the 8 queens 

 of F. obscuriventris tried with workers of F. subsericea, 5 were 

 adopted, that these 5 were with colonies of from 8 to 12 workers 

 and that those that were not adopted were with colonies of from 

 2 5 to 75 workers. The ease with which these queens are adopted 

 in small colonies of subsericea, the decided tendency on the part 

 of many of the workers, even in the large colonies, to begin licking 

 and caressing the queens almost from the first, the inquilinous 

 tendency shown in the behavior of the queens themselves and 

 especially the finding of the mixed colony mentioned in the note 



