34O O. E. PLATH. 



For several days, everything went well, but on August 10, it was 

 noticed that thefervidus workers were daubing the pennsylvanicus 

 queen and worker with honey, a habit which has been referred 

 to before. On the next day, the pennsylvanicus worker failed to 

 return, but the queen, although her pile was constantly soaked with 

 honey, lingered about the nest until August 21, when she disap- 

 peared. A few days later, several fervidus males hatched in this 

 colony, but no adults of Bremus pennsylvanicus were obtained 

 from any of these mixed colonies. 



The nesting habits of Bremus pennsylvanicus have been de- 

 scribed by Franklin ('12/13) Howard ('18), and Prison ('16, '17, 

 '18, '21). Judging from the data published by these authors, 

 the nests are usually situated on the surface of the ground, but 

 occasionally also in the ground, or in birds' nests. The largest 

 nest taken by Franklin (p. 405) contained I queen, 23 males, 53 

 workers, and 78 cells with larvae in them, of which 18 were queen 

 cells. 



In the vicinity of Boston, Bremus pennsylvanicus is compara- 

 tively rare. The queens are the last to appear in spring, the first 

 one in 1922 being seen on May 29, and the first worker on July 22. 

 Most nests are probably started in June. A number of males of 

 this species were taken in September, and therefore the colonies, 

 like those of Bremus fervidus, probably do not break up until the 

 latter part of September or the beginning of October. 



According to Mr. T. H. Prison ('17, '18) and Mr. Court W. 

 Ranslow (cf. Howard, '18), the workers of Bremus pennsylvanicus 

 are rather vicious. After they had oviposited, this was also true 

 of the pennsylvanicus queens used in my breeding experiments. 

 On several occasions, they seized my forceps, tried to sting them, 

 and clung to them so tenaciously that they could be lifted out of 

 the nest-box. 



While these experiments were in progress, a number of other 

 observations were made which will be presented in another paper. 



LITERATURE CITED. 

 Dahlbom, G. 



'32 Bombi Scandinaviae Monographice Tractati et Iconibus Illustrati. Londini 



Gothorum, Typis Berlingianis. 

 Franklin, H. J. 



'12/13 The Bombidae of the New World. Trans. Amer. Ent. Soc., Vol. 38, pp. 

 177-486, Vol. 39, pp. 73-200, 22 pis. 



