THE ORGANIZATION OF INSECT SOCIETIES 



433 



other, and the parts in turn determine the 

 activities of the whole. 



The experiments of von Frisch (1942, 

 1943, 1946) illustrate many aspects of be- 

 havior integration of honeybees, and also 

 demonstrate the role of conditioned or 

 learned behavior in association with various 

 chemical, tactual, and visual responses. By 

 placing sugar-water in dishes on various 

 colors and shades of cards, von Frisch 

 trained worker bees to come to certain 

 colors. He was thus able to determine 

 their visual response and sensitivity. The 

 workers are color-blind for scarlet red, re- 

 acting to this color (above 650 i^h) as they 

 do to black. The bees react to ultraviolet 

 light (down to 300 m-h). By switching 

 colored cards during the approach of the 

 bee to the food, while the bee is feeding, 

 and while the bee is leaving, it was deter- 

 mined that the bee returns to the color as- 

 sociated with the food at the time of ap- 

 proach, and not to the colors placed under 

 the food at the time of feeding or leaving. 

 A "scout" bee that locates a food supply 

 returns to the nest and performs a dance 

 on the honeycomb in the presence of other 

 workers. The dance consists of motion in 

 small circles with short steps. It may last 

 a minute or longer and may be repeated in 

 diflFerent places on the comb. Other bees, 

 pushed by the dancer, are excited and may 

 be seen touching the abdomen of the danc- 

 ing bee with their antennae. Soon a group 

 of bees is stimulated to follow the dancer 

 to the food source and its associated color. 

 When the group returns to the hive with 

 filled crops, each bee in turn may perform 

 a dance and stimulate other bees to follow 

 it back to the food source. 



Bees may also be trained to respond to 

 certain odors. The scout bees impart the 

 odor associated with the food to other bees 

 in the hive. This is probably the explana- 

 tion of the tendency of bees to visit one 

 kind of flower for a definite period. Were it 

 not for this temporary specialized behavior, 

 bees would not be the efficient pollinizing 

 agents that they are and flowers would 

 probably not have evolved the remarkable 

 adaptations for pollination by such insects 

 (pp. 248 and 250). During the food dance, 

 von Frisch transferred pollen from Cam- 

 panula to Rosa and found that the bees 

 trained on Campanula returned to the Rosa, 

 thus showing that the scent of the pollen 



took precedence over the scent of the 

 flower. 



The scout bee is able to communicate the 

 direction and distance of food to other 

 workers by means of its food dance on the 

 comb. If the food is 50 meters or less from 

 the hive, the scout performs a turning 

 dance. If the distance is between 50 and 

 100 meters, the dance includes a short 

 straight run between the turns. The ab- 

 domen is wagged during this straight run. 

 At distances greater than 100 meters, the 

 number of straight runs decreases per unit 

 of time, while the wagging motions in- 

 crease. If the food is toward the sun, the 

 straight run is vertically upward on the 

 comb. A downward run indicates direction 

 away from the sun. A deviation of 10 de- 

 grees to the right of the vertical indicates 

 food 10 degrees to the right of the sun. 

 Any angle to the right or left of the vertical 

 corresponds to the angle to the right or 

 left of the sun. If the comb is on its side, 

 the straight run of the dance is in the di- 

 rection of the food. Direction and distance 

 are thus communicated to other workers by 

 the scout bees (Schmieder, 1947). 



Bees with partially filled crops or pollen 

 baskets do not perform dances, so that the 

 number of bees visiting any source of food 

 is in proportion to the abundance of the 

 food. Flying bees are also attracted to 

 rich sources of food by the emission of scent 

 by the bees that have found the food. The 

 dorsal scent gland is in a fold between the 

 fifth and sixth abdominal segments, which 

 are stretched out in the presence of abun- 

 dant food. 



It is often difficult to separate the 

 chemical and tactile sense involved in a 

 particular behavior pattern among the social 

 insects. Possibly both types of sensory 

 reponse are associated in the commonly ob- 

 serv'ed mutual antennal tapping among 

 ants. As already pointed out (p. 430), both 

 chemical and tactile senses are included 

 under the concept of trophallaxis. 



The sexual attraction between male and 

 female termites (Reticulifermes) after the 

 colonizing flight surely involves both olfac- 

 tory and tactile response, but the two 

 responses are separable (Emerson, 1933). 

 The male is attracted to the female bv an 

 odor emitted from her raised abdomen. 

 Once the male has touched the female, she 

 lowers her abdomen and moves oflF with the 



