14 smithsonian miscellaneous collections vol. 65 



4. Experiments in Feeding Bees Foods Containing Bitter 



Substances 



Two lots of 25 grams of cane-sugar candy each were thoroughly 

 mixed, one with 500 milligrams of finely pulverized quinine sulphate 

 and the other with a like quantity of strychnine sulphate. Each 

 mixture was then divided into five equal parts. To the writer the 

 odor from each mixture was exactly like that from pure cane-sugar 

 candy, although the human nose is able to detect a faint odor emitted 

 from a large quantity of either quinine or strychnine. Strychnine is 

 regarded as the bitterest of all substances. To the writer both of these 

 mixtures were extremely bitter. Equal amounts of pure cane-sugar 

 candy and of these other two foods were fed to fresh bees in the 

 usual manner. Five minutes after introducing the foods, the first 

 count was taken and thereafter every 15 minutes. As an average for 

 the 100 bees for five counts, 47.4 per cent were observed eating pure 

 cane-sugar candy, 5.8 per cent eating candy containing quinine, and 4 

 per cent eating candy containing strychnine, making a total average 

 of 57.8 per cent eating at any one count. 



These experiments were repeated by feeding fresh bees only the 

 candies containing quinine and strychnine. As an average for the 

 100 bees for five counts, 39.4 per cent were seen eating candy con- 

 taining quinine and 4 per cent eating candy containing strychnine, 

 making a total average of 43.4 per cent eating at any one count. An 

 hour after introducing the foods, the bees began to die. 



Twenty-five grams of cane-sugar candy were mixed with 500 milli- 

 grams of liquid picric acid, and then the mixture was divided into five 

 equal parts. This food was almost as bitter as quinine and emitted 

 a faint odor, different from that of pure cane-sugar candy. The 

 preceding experiments were repeated by feeding fresh bees this 

 mixture, candy containing quinine and pure cane-sugar candy. As an 

 average for the 100 bees for five counts, 19.2 per cent were seen eating 

 pure cane-sugar candy, 34.4 per cent eating candy containing picric 

 acid and 2.2 per cent eating candy containing quinine, making a total 

 average of 55.8 per cent eating at any one count. 



The preceding was repeated by using the same amount of powdered 

 picric acid instead of the liquid picric acid and by discarding the candy 

 containing quinine. As an average for the 100 bees for five counts, 

 45 per cent were observed eating pure cane-sugar candy and 1 per 

 cent eating candy containing picric acid, making a total average of 46 

 per cent eating at any one count. 



