PSYCHE 



VOL. XXIX. OCTOBER-DECEMBER 1922 Nos. 5-6 



NOTES ON THE NESTING HABITS OF SEVERAL NORTH 

 AMERICAN BUMBLEBEES. ' 



By 0. E. Plath. 



Massachusetts Institiite of Technolog^^ Cambridge, Mass. 



In a comprehensive paper on the bumblebees of Central 

 Europe, Friese and Wagner (1910, p. 69) make the following 

 statement: ''Insbesondere lasst die Kenntniss der Nester noch 

 allzuviel zu wiinschen iibrig, was um so empfindlicher ins Ge- 

 wicht fallt, als gerade von dieser Seite her die vielleicht wertvoll- 

 sten Aufschllisse zu erwarten stehen, weil alien Folgerungen, die 

 lediglich auf einem durch Fang der frei fiiegenden Tiere gewon- 

 nenen Materiale basieren, notwendigerweise eine gewisse 

 Unsicherheit anhaften muss." The truth of this statement has 

 been amply proved by the work of Drewsen and Schiodte (1838), 

 Smith (1876), Schmiedeknecht (1878), Hoffer (1881, 1882/83, 

 1885, 1888), Coville (1890), Sladen (1899, 1912, 1915), and 

 Frison (1916, 1917, 1918, 1921). 



What Friese and Wagner (p. 69) have to say concerning 

 the Central European bumblebees, is even more true of our 

 American species. Of the 86 New World species of Bremus 

 (Bombus) listed by Frankhn (1912/13, 1914) and Frison (1921a), 

 the nesting habits of only 17 have thus far been recorded,^ but 

 some of these data are so incomplete that they have little or no 

 value. It is the object of this paper to add another species 

 {Bremus ocddentaUs Greene) to those enumerated below and 

 to supplement our knowledge concerning the nesting habits of 



iContribution from the Entomological Laboratory of the Bussey Institution, Harvard 

 University, No. 211. 



2Those of Bremus a/finis, auricomus, bimaculatus, borealis, cayennensis, emelice {Ihor- 

 acicus), fervidus, jlavifr'ons, impalicns, pennsylvanicus, per plexus, rufocinctus, separalus, 

 ternarius, terricola, and vagans\hv Putman (1865), Coville (1890), Hudson (1892), von Ihering 

 1903), Franklin (1912/13), Howard (1918), and Frison (1916, 1917, 1918. 1921). 



