NOTES ON BOMBIDAE, AND ON THE LIFE HISTORY 

 OF BOMBUS AURICOMUS ROBT. 



Theodore H. Prison, Champaign, Illinois. 



Up to the present, little work has been done on the life- 

 history of our American Bombidce. Mr. F. W. L. Sladen, in 

 his admirable book, "The Humble-bee," has given us, however, 

 the principal facts in the life-history of the common English 

 Bombidce, besides many other observations of importance and 

 interest. 



There are several reasons to account for the dearth of lit- 

 erature on the subject of the life-history of bumblebees. Unlike 

 the honey bee, all the individuals of Bombus, with the exception 

 of the new queens, die in fall. The new queens hibernate 

 throughout the winter in various situations, and issue forth in 

 spring, to start new colonies. In order to obtain a good, clear, 

 and accurate account of the life-history of Bombus, constant 

 observations must be made, from a very early date in the 

 history of the colony. 



In spring, the nests of Bombus are less likely to be found than 

 later in the season. This is mainly due to the fact that the 

 nests are then smaller, and contain fewer bumblebees to attract 

 attention. Many of the nests of Bombus, mentioned in the 

 literature, were found and opened in late summer or fall. The 

 opening of a nest in the late summer or fall permits only of 

 observations regarding the size of the colony, the number of 

 bumblebees of each caste present, the number of eggs, larvae, 

 pupae, arrangement of the comb, and various other miscella- 

 neous notes. The attempt to transfer a nest in spring or early 

 summer from the field to an observation box, and to carry on a 

 series of observations, is very apt to cause the queen to abandon 

 her nest. In April, 1910, I found many Bombus queens of various 

 species, occupying old, deserted nests of field mice. These 

 nests were in an old pasture on the surface of the ground. No 

 adults had as yet emerged in any of the nests examined, the 

 nests containing eggs or small larvae, or both. Not one of these 

 nests was transferred to an observation box with success; the 

 queen either deserting the nest after several days, or if confined, 



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