NO. 2 RECOGNITION AMONG INSECTS McINDOO 5 



7. The hive odor (exhalation odor, colony odor). The hive odor is 

 composed normally by a mixture of the preceding odors, or of some of them. 

 Single bees, therefore, besides their individual odors, possess the family 

 odor and especially the common adhering hive odor, which forms the 

 dominant factor in the various actions tovvrard hive mates and hive strangers 

 — that is, in mutual recognition between bees. 



Von Buttel-Reepen furthermore describes an abnormal hive odor 

 which is caused by abnormal conditions among the occupants of the 

 hive, and abnormal odors which are generated by disease (dysentery, 

 foul brood, etc.). 



To support the preceding views, von Buttel-Reepen gives no proofs 

 other than his experiences as a bee-keeper, which are far from being 

 conclusive, and the present writer, who has experienced much diffi- 

 culty trying to prove his views experimentally, has had only partial 

 success. 



To know the part that odors play in the behavior of bees will be 

 of considerable importance to bee-keepers, because the introduction 

 of queens, uniting, and various other manipulations may be per- 

 formed more successfully. 



I. ODORS EMITTED THAT MAY BE PERCEIVED BY A PERSON 



From April to October, 191 3, the writer devoted practically all 

 his time to a study of the odors produced by the honey-bee, and 

 not being satisfied with some of the results obtained, several of the 

 experiments were repeated the following summer. When this study 

 was first begun, only the more pronounced odors — the hive or bee 

 odor, brood odor, honey odor, and wax odor — could be distinguished 

 by the writer, but before the close of the first summer he was able to 

 distinguish the three castes of bees merely by smelling them. The 

 details are as follows : 



Old workers constantly give off the characteristic bee odor; and 

 when seized, they emit another distinct odor which comes from the 

 poison ejected through the sting. No difference between the odor 

 of a guard and that of a fanner could be distinguished ; the odor from 

 each closely resembles the hive odor, that is, the odor which comes 

 out of a hive when the hive cover is removed. A worker carrying 

 pollen gives off besides the bee odor another odor whjch comes from 

 the pollen. 



The younger the workers the less pronounced is the bee odor 

 emitted. To the human nose the odor emitted by nurse bees and wax 

 generators is much less pronounced than is the odor from old workers. 



