76 O. E. PLATH. 



XX. THE POSITION OF THE NEST AND HIBERNATION. 



Wagner (p. 7) states that it depends upon the fall weather 

 when bumblebees begin to hibernate, and that queens reared in 

 well-protected nests (e.g. those in the ground or in hay stacks) 

 take up their winter quarters later than those reared in surface 

 nests. These two statements are likewise incorrect. In Europe, 

 the queens of Bremus pratorum, a species which frequently nests 

 in the ground (cf. Armbruster, 1914, p. 686), begin to hibernate 

 in July (cf. Sladen, 1912, p. 12), while those of such surface- 

 nesting species as agrontmand muscorum do not begin to hibernate 

 until at least a month later. The same thing holds true for 

 some of our American species. Here in the vicinity of Boston, 

 the nests of Bremus bimaculatus and Bremus terricola are almost 

 always subterranean, and yet the majority of the queens of 

 these two species take up their winter quarters in July, while 

 those of Bremus fervidus and Bremus vagans, species which 

 usually nest on the surface of the ground, do not begin to hiber- 

 nate until the latter part of August. These facts indicate that 

 the beginning of hibernation depends on the species rather than 

 on the weather and the position of the nest. 



LITERATURE CITED. 

 Armbruster, L. 



'14 Probleme des Hummelstaates. Biol. Centralbl., Vol. 34, pp. 685-707, 

 fig. 5, pi. 2. 



Bachmann, M. 



'15 Biolgische Beobachtungen an Hummeln. Mitteil. Miinch. Ent. Gesellsch., 



Vol. 6, pp. 71-112. 

 Buttel-Reepen, H. v. 



'03 Die stammesgeschichtliche Entstehung des Bienenstaates, sowie Beitrage 

 zur Lebensweise der solitaren und sozialen Bienen. (Hummeln, 

 Meliponen, etc.) Georg Thieme, Leipzig. 

 Coville, F. V. 



"90 Notes on Bumble-Bees. Proc. Ent. Soc. Washington, Vol. i, pp. 197-203. 

 Dahlbom, G. 



'32 Bombi Scandinaviae Monographice Tractati et Iconibus Illustrati. Londini 



Gothorum, Typis Berlingianis. 

 Franklin, H. J. 



'i2/'i3 The Bombidae of the New World. Trans. Amer. Ent. Soc., Vol. 38, 



pp. 177-486, Vol. 39, pp. 73-200, pis. 1-22. 

 Friese, H. und Wagner, F. v. 



'04 Ueber die Hummeln als Zeugen natiirlicher Formenbildung. Zool. Jahrb., 



Supplement, Vol. 7, pp. 551-570, pis. 29-30. 



'10 Zoologische Studien an Hummeln. I. Die Hummeln der deutschen Fauna. 

 Zool. Jahrb., Abt. Syst., Vol. 29, pp. 1-104, P'S. 1-7, 20 figs. 



