1901 



GLEANINGS IN BEE CULTURE. 



639 



ASCENT-PRODUCING ORGAN IN THE ABDOMEN 

 OF THE BEE. 



The Scent Produced Forms a Means of Communica- 

 tion between the Members of a Swarm or 

 Colony. 



BY F. W Iv SLADEN. 



The following is a buuimary of an article on 

 the above subject, contributed to the British 

 Bee Journal : 



Last July, through the apparent absence of 

 definite evidence that bees are able to hear 

 ordinary sounds, I was led to investigate the 

 phenomenon known as the "joyful hum" 

 among bees. In "The Bee-keeper's Guide- 

 book," 16th edition, page 26, we read, "The 

 joyful hum of the bees as they enter the hive 

 will entice others to follow." I asked myself 

 the question, " Is it entirely the hum that at- 

 tracts the bees, or is there any thing else that 

 exerts the influence?" It was in endeavor- 

 ing to answer this question that I was led to 

 make certain observations, and to form a the- 

 ory which I have been unable to find stated in 

 any work on bees, and of which the following 

 is a short account : 



If a comb be lifted out of a hive, and the 

 bees on it be shaken off on to the alighting- 

 board, many of the bees will not at once rush 

 into the entrance, but they will pause at the 

 portal, and commence humming, evidently 

 for the purpose of attracting their mates. 

 When humming in this way the bee adopts a 

 certain peculiar attitude. She stands with her 

 head turned toward the entrance. She ele- 

 vates her abdomen, and uncovers a narrow 

 white membrane situated at the base of the 

 6th dorsal segment, which, when at rest, is 

 entirely hidden, and covered by the 5th seg- 

 ment. As this membrane is near the ex- 

 tremity of the abdomen it seems but reason- 

 able to suppose that the abdomen is especially 

 elevated to give prominence to it. The " joy- 

 ful hum," whether it is made, first, under the 

 above circumstances; or, second, when a swarm 

 is being hived ; or, third, when a queen is ac- 

 companied by a few workers in a cage ; or, 

 fourth, when a young or tired bee discovers, 

 after more or less difficulty, the entrance of 

 her hive, is always accompanied with the pro- 

 trusion of the above-mentioned membrane ; 

 and it then has the effect of attracting other 

 bees ; and when a number of bees hum in this 

 way, as when a swarm is being hived, their 

 attractive effect on other bees is very marked. 

 On the other hand, when fanning is done 

 merely for the purpose of ventilation, as at 

 the mouth of the hive in very hot weather, 

 the above-mentioned membrane is not, or, at 

 most, is scarcely exposed, and no attractive 

 effect seems to be intended or is observable. 



After making the above observation it seem- 

 ed to me clear that the membrane in question 

 had a great deal to do with the attractive ef- 

 fect produced during the "joyful hum;" 

 and, calling to mind the extremely meager 

 evidence we have that supports the theory 

 that the sense of hearing, as we understand it, 

 is developed in either ants or bees, and, on the 

 other hand, the strong evidence we have in 



favor of the high development of the sense of 

 smell in these insects (both points being con- 

 firmed, in the case of bumblebees, by recent 

 experiments of mine), I was led to form the 

 theory that the membrane above mentioned 

 (A, below) contains scent-glands, and that 

 these produce a certain scent which, when t?he 

 membrane is exposed, forms an important 

 means of communication, by attraction, be- 

 tween the individuals of a colony or swarm. 

 The fanning of the wings during humming 

 would help to distribute this scent. 



To endeavor to prove my theory, when hiv- 

 ing a swarm last July I put my nose close 

 down over the mass of humming bees that 

 were spread out on the hiving-board, to try to 

 detect the suspected scent. I certainly smell- 

 ed a curious, somewhat pungent odor, resem- 



Tip of distended abdomen of worker honey-bee seen 

 from above, slightly enlarged. 

 4D, sp, 6D. -)th, .")ih, and (jth dorsal segments. 

 61', tiih ventral segment. 



A, NassonofT's organ. 



B, long hollow depression on the outer margin of 

 the same. 



bling slightly the scent of formic acid that is 

 produced when a nest of Formica rufa (the 

 common European wood ant) is disturbed ; 

 and, though I was not able at the time to 

 prove it, 1 strongly suspected that it was the 

 scent produced by the above organ. A sweet 

 " seaweedy " scent, which I recognized to be 

 of the same nature, was produced by a few 

 bees accompanying a caged queen a few days 

 later. 



I then endeavored to cut off communication 

 in a line of humming bees by dividing it into 

 two parts by the interposition of a thin canvas 

 screen charged with various kinds of scent, 

 which I hoped would nullify the effect of the 

 bees' scent, while allowing a free passage 

 through it for the sounds they produced. If 

 I could do this I thought it would, to a great 

 extent, prove that " humming " bees commu- 

 nicate by the scent they produce, and not by 

 their sound. This experiment had no definite 

 result. 



