August, 1909. 



American Hee Journal 



A Study of the Eyes of Bees 



BV C. P. DADANT. 



The discussion of the question of dis- 

 tances traveled by bees in search of 

 honey has raised the question of eye- 

 sight in bees. On this point, as in many 

 others, there seems to be some difference 

 of opinion. 



As my readers are aware, the honey- 

 bee is provided with 5 eyes, 2 very large 

 compound eyes, placed on each side of 

 the head and three small eyes called 

 scientifically "ocelli," arranged in a tri- 

 angular position at the top of the head. 



There is uniformity of opinions to the 

 purpose of the small eyes. The honey- 

 bee needs to see in the fields at con- 

 siderable distance, but it needs also to 

 see in the hive at a very close range, and 

 entirely in the dark. The ocelli seem 

 fitted for that purpose. Thos. W. Cow- 

 an, in his anatomical description of the 

 honey-bee, quotes Miiller, a German, as 

 remarking that, "from their structure, 

 their power of vision was confined to 

 the perception of very near objects." 

 Lowne, an English entomologist quoted 

 by the same author, says that the func- 

 tion of the ocelli is the perception of the 

 intensity and direction of the light 

 rather than vision in the ordinary ac- 

 ceptation of the term. They conclude 

 that the ocelli are useful in dark places 

 and for near vision. Bees certainly can- 

 not see a distance, in the dark, and the 

 use of the eyes must be confined to a 

 reach of less than 2 inches when inside 

 of the hive. .Ml apiarists who have 

 tried handling bees in the dark know 

 how they fly at random and crawl about 

 over or through one's clothes. But the 

 least motion, within a couple of inches 

 near the entrance in a dark night will 

 draw their attention and cause them to 

 fly at the intruder in defense of their 

 home. They will even resist intrusion 

 more promptly at night than in the day- 

 time, probably because during the day 

 they can better discern the actions of 

 persons at a distance and more readily 

 realize whether danger is at hand. 

 Bees do not take offence at slow mo- 

 tions, and this is plausible. We will 

 ourselves beware of a nervous horse and 

 avoid his heels more carefully than 

 those of a peaceable animal. The bees 

 seem to have as much tact in recogniz- 

 ing nervous persons as the most intelli- 

 gent of our domestic animals, and even 

 more than human beings possess. 



Cheshire appears to have a like opin- 

 ion concerning the ocelli of the bee, say- 

 ing that they are very convex and are 

 adapted to short-distance vision. The 

 French entomologist, Girard, expresses 

 himself in almost the same words, say- 

 ing that the ocellus presents a very con- 

 vex cornea in connection with a micro- 

 scopical function at very short range. 

 One writer, however, Rauschenfels, in 

 his explanation of the excellent micro- 

 scopic studies of Count Gactano Barbo, 

 engraved by Clerici in the '"o's, says 

 that the ocelli may serve to see at great 

 distances. 



The compound eyes are formed of a 

 great number of facets. Cowan says 

 from 3S00 to 5000 in the worker, and 

 many more in the drone. Cheshire, 

 whose authority seems to be accepted 



even by foreign scientists, places the 

 number of facets in each compound eye 

 of the worker-bee at about 6300, which 

 would give that insect 12,600 different 

 e}"es, turned to almost all points of the 

 compass. Most of the writers spend a 

 great deal of time arguing whether the 

 bee does not have a multiple reproduc- 

 tion of the objects seen, similar to what 

 we see when we look through a prism. 

 It seems to me that it is only necessary 

 to think of our own eyes, two in num- 

 ber, yet not giving us a double sight of 

 objects, to understand that the numer- 

 ous eyes of the bee give her only a sin- 

 gle view of objects seen; but the field 

 of vision given by so many eyes is great- 

 ly enlarged over our own. By closing 

 one eye we immediately perceive how 

 much reduced becomes our field of vis- 

 ion and we thus realize how much more 

 and how much better we could see in 

 all directions, if we were possessed of 

 compound eyes, returning all their com- 

 bined impressions to one nerve center. 



That the compound eyes are of use 

 to see at a distance is doubted only by 

 one scientist, whom I mentioned in a 

 previous article. Mr. Bonnier, a Pro- 

 fessor at the Sorbonne, denies the sight 

 of bees at long distances and claims 

 that they can find their home, if they 

 are blinded with a preparation of dark- 

 ened collodion. Yet he acknowledges — 

 nay, he teaches — that which the merest 

 novice in apiculture knows, that the 

 young bee, at her first flight, carefully 

 scans the surroundings of her hive be- 

 fore taking her departure for the field. 

 The first flight of the young bees is an 

 iiUeresting sight, for they circle over 

 and over again around the entrance, en- 

 larging the circles as they go until they 

 are lost sight of. 



How far can the bees see? Some one 

 calls my attention to the fact that Lowne 

 has calculated from the angle formed by 

 the lenses of the compound eye that at 

 a distance of 20 feet, bees can distin- 

 guish objects from one-half to one inch 

 in diameter. But can they see a field of 

 clover 2 miles away, if the configura- 

 tion of the country is such as to permit 

 them such a range? This is a point that 

 1 would like to see settled. Personally, 

 I doubt it very much, even though I see 

 it supported in an editorial in Gleanings 

 for July 1st. The editor, E. R. Root, 

 seems to agree with me as to the range 

 of hce-pasturc — he puts the limit at a 

 mile and a half for ordinary range, but 

 tliinks tliat in a hilly country bees will 

 fly farther because they can see farther. 

 I am enclined to think that their olfac- 

 tory organs are even more acute than 

 their sight and it seems to me that, when 

 they go to greater distances than above 

 mentioned, it is with the guidance of the 

 nrlor of large fields of strong-smelling 

 blossoms, such as buckwheat or bass- 

 wood. 



Tn spite of their marvelous eyes, bees 

 make errors in location. Many young 

 bees, after the first flight, return to the 

 wrong hive, if they happen to be loca- 

 ted where many hives of like form and 

 size are closely gathered. These errors 

 of the young bees can be most easily 

 detected when a new race is introduced 

 ill the apiary. A few yellow Italians are 

 rendilv traced to the hive of common 



bees wliich they may have entered by 

 mistake. If the season is favorable, as 

 they do not come as robbers, they are 

 often very peaceably welcomed by their 

 neighbors. 



The eyes of the drone are very much 

 larger than those of either workers or 

 queens. They appear to occupy the en- 

 tire side of the head, and join together 

 at the top, so tliat the ocelli are in front 

 of them instead of between them. Why 

 such powerful sight — 26,000 facets in the 

 eyes of a single insect? Because the 

 drones spend their time of flight seek- 

 ing for a mate. The queen must be 

 found and met, in the air, on the wing. 



Even if we were to grant to the bee a 

 "sense of direction," such as is claimed 

 for them by Bonnier, which would en- 

 able them to find their home from a 

 point not previously visited by them, 

 and which would be a sort of instinct, 

 we would still have to recognize that 

 their eyes must be powerful to enable 

 them to find the hole in a tree in the 

 heart of the forest, when seeking for a 

 new abode for the swarm. That the 

 bees should find the key-hole of the 

 honey-house, to carry away the honey, 

 may be explained by their organs of 

 smell recognizing the presence of their 

 product in that honey-house, but the 

 liollow tree has no smell that can at- 

 tract them. Can we deny the existence 

 in tliem of even more acute senses than 

 our own? 



Hamilton, 111. 



Management of Swarms 



BY EDWIN BEVINS. 



This is July 17. Swarming began in 

 this yard in the last days of June, and 

 has been going on daily ever since. 

 Some days I had the satisfactiofi of see- 

 ing 2 or 3 swarms cluster together. 

 Saved work. I used some repressive 

 measures to delay and prevent swarm- 

 ing, but repressive measures this year 

 do not repress much. The colonies from 

 whicli swarms issued were treated in a 

 variety of ways. One was divided into 

 3- frame nuclei, each nucleus having a 

 comb with one or more sealed queen- 

 cells. Many others had a 3- frame nu- 

 cleus taken from them and the other 

 combs used to help colonies not quite 

 strong enough for work in supers. A 

 few were allowed to recuperate on the 

 old stand. In the beginning I did not 

 want any increase at all, and when I 

 looked around a few days ago and saw 

 a lot of hives from which swarms had 

 pone, and a lot of supers on them in 

 which no storing was being done right 

 in the midst of a honey-flow, I felt like 

 saying with Tennyson, 



"I would that my tongue could utter 

 The thouRhts that arise in me" 



— without swearing. I had read and 

 pondered a good many of the ways ad- 

 vised for the prevention of increase, but 

 was not satisfied with any of them, but 

 the matter was getting serious. The 

 hopes for early section honey to sell 

 were going glimmering. A few days 

 ago I prepared a hive for the next 

 swarm with a set of empty combs and 

 about the time it was ready a big swarm 

 was clustered readv for it. As soon as 



