1922] Notes on Nesting Habits of North American Bumblebees 199 



colony over to me for observation. Of these 14 nests, 1 was 

 situated 2 ft. above ground, in a stone wall, 4 were surface nests, 

 and the remaining 9 were subterranean. These latter were from 

 § to 1 ft. below the surface of the ground and had tunnels vary- 

 ing from i to 2 ft. in length. As in the case of Bremus impatiens, 

 several of the nests taken during the early part of the summer 

 contained one or more dead fervidus queens besides the one 

 living. 



Franklin (1912/13, I, p. 393) states that the nests of Bremus 

 fervidus never contain a large number of bees, the largest nest 

 taken by him consisting of 47 individuals, of which 37 were 

 workers. However this is not always the case. Of the 13 nests 

 which I took, 3 consisted of from 100 to 125 workers each, and 

 this despite the fact that one of them was taken comparatively 

 early in the season (July 18, 1922). Each one of these 3 colonies 

 later produced more workers and more than a hundred males and 

 young queens. 



Of the 14 nests, one contained 22 large, dipterous larvse 

 which, judging by Sladen's (1912, p. 74) figure, were probably 

 those of Volucella. Attempts to rear the larvae proved un- 

 successful. 



When the first large Bremus fervidus nest was discovered 

 during the summer of 1921, I at first thought I was dealing with 

 a surface nest, for a large quantity of nesting material which con- 

 tained about a dozen workers, covered the opening of the tunnel. 

 This was also the case with 2 populous, subterranean nests of 

 this species which I took during the summer of 1922. In Europe, 

 Hoffer (1882/83, II, pp. 35, 36), Harter (1890, p. 74), and 

 Bachmann (1915, p. 76), each found a similar "Vornest" or 

 ''Scheinnest" in connection with the nests of Bremus pomorum. 

 The only plausible explanation for these "pseudo-nests" seems 

 to be that more nesting material is gathered by the colony than 

 the nest cavity can hold. 



In the vicinity of Boston, the queens of Bremus fervidus 

 appear in large numbers during the latter half of May. In 1922 

 the first one was seen on May 7th. Most nests are probably 

 started between the middle of Mav and the middle of June. 



