LIFE-HISTORY OF BOMBUS 



elusion that the original queen tolerates the intruder 

 only so long as the latter has no eggs to lay, the 

 two mothers being unable to endure one another's 

 presence. 



Each queen that attaches herself to the nest of 

 another means one less colony started, and it is 

 hard to see of what advantage this habit can be to 

 the species except the survival of the best fighters. 

 One would suppose that the attachment of one or 

 more queens to a nest might be a safeguard against 

 the perishing of the young, should their mother get 

 lost, but my observations show that the satellite is 

 not sufficiently settled in life to assume the care of 

 the brood until she is about to lay eggs. It is, in 

 fact, the imminence of motherhood that makes her 

 look after the brood, although success in a duel 

 rouses her to do so. 



I have discovered one very interesting exception 

 to the rule that only the queens of the same species 

 prey upon one another. 



On June 15, 1894, I found a nest containing a 

 terrestris queen with ten workers, all of which were 

 of the closely allied species lucorum, and a dead 

 lucorum queen, evidently the mother of the workers. 

 On the same day I found another nest containing 

 about twenty workers, all lucorum, with a terrestris 

 queen and the decaying remains of two lucorum 

 queens. These, and several similar cases met with 

 in later years, leave no doubt that the terrestris 

 queens frequently enter the lucorum nests, kill the 

 lucorum queens, and get the lucorum workers to 



