326 O. E. PLATH. 



New England species of Bremus. During the following spring and 

 summer, about fifty queens belonging to eleven 1 of the thirteen 

 New England species listed by Franklin ('12/13, pp. 190, 191) 

 were captured in the Arnold Arboretum, within the city limits of 

 Boston. After being confined for various periods of time, at 

 least one queen of each of these species became broody and ovi- 

 posited, but self-supporting colonies were only produced by six. 2 

 The names of these six species, and the number of colonies ob- 

 tained from each, are listed in the accompanying table: 



TABLE I. 



Number of 

 Species. Colonies. 



1. Bremns bimaculatus Cresson 2 



2. Bremus impatiens Cresson i 



3. Bremus per plexus Cresson . . . . i 



4. Bremus separalus Cresson 2 



5. Bremus ternarius Say I 



6. Bremus ragans Smith . 2 



Before discussing the methods which were used in these breed- 

 ing experiments, it seems desirable to describe briefly those em- 

 ployed by the earlier workers. Hoffer ('82) supplied his queens 

 with nesting material and plenty of fresh flowers. Each queen 

 was probably confined in a separate box. At first, Sladen ('12) 

 also confined each queen separately, giving her an artificial nest 

 and a liberal supply of honey and pollen, but he was unable to 

 get a colony started in this way. He then placed two queens 

 (of the same species) in each box, and this method yielded better 

 results. However, Sladen (p. 131) found that one of the queens 

 always killed her companion about the time the eggs were laid, 

 and that the victorious queen invariably deserted the nest, unless 

 she was supplied with one or more workers. In order to avoid this 

 killing of queens, Sladen (p. 132) modified the experiment by 

 confining one queen with one or more workers in each box. This 

 also proved successful, even when the workers were of a different 

 species. 



1 Bremus affinis, bimaculatus, borealis, fervidus, impatiens, pennsylvanicus , per- 

 plexus, separatus, ternarius, terricola, and vagans. . 



"On June 13, several of these incipient bumblebee colonies were exhibited at 

 a meeting of the Cambridge Entomological Club- 



