THE POISONING OF BEES BY ORCHARD SPRAYS 77 



When the bees were killed by lime-sulfur, somewhat dififerent symptoms 

 were noted. The actions of the bees were less violent, and they showed a 

 tendency to be inactive and sluggish. 



Bees poisoned by nicotine-sulfate reacted in much the same manner as 

 noted following a contact application of nicotine spray. There was very 

 little violent action. The bees quickly lost control of their limbs and be- 

 came incapable of any motion except to feebly move legs or antennae. 



Mortality in a nucleus colony under controlled conditions. 



Feeding tests had shown that, while the combination of lead arsenate, 

 lime-sulfur, and nicotine sulfate at strengths used for orchard spraying 

 was distinctly repellent to the bees, it proved to be very toxic even when 

 taken in small amounts, and its killing action was very rapid. To deter- 

 mine the reaction of bees toward blossoms sprayed with the combination, 

 a three-frame nucleus with eggs, brood, and some stores was placed in a 

 section of tightly screened greenhouse. A thin coating of whitewash on 

 the glass diffused the sunlight somewhat and also reduced abnormal activ- 

 ity of the bees. The colony was kept well supplied with fresh blossoms 

 and allowed several days to become accustomed to tiie surroundings, and 

 the normal daily mortality determined. 



Bloom sprayed with the regular combination was then introduced and 

 allowed to remain for two days. It was then withdrawn and fresh un- 

 sprayed blossoms supplied the bees during the rest of the experiment. The 

 following indicates the daily mortality. 



Total 2662 



* Days sprayed Ijlossoiiis were offered the bees. 



The bees were strongly repelled by the spray and would not even alight 

 on the blossoms until it had dried. During the next day and until the 

 sprayed blossoms were withdrawn, the bees were visiting them in numbers, 

 although they never worked them as freely as they did unsprayed bloom. 

 The rapid rise in mortality following exposure to the sprayed flowers in- 

 dicated that bees, altliough apparently reluctant to work sprayed bloom, 

 nevertheless would do so if no unsprayed blossoms were available. It also 

 pointed out how toxic the spray is to bees, once they feed upon it. Upon 

 the sprayed blossoms the bees naturally obtain the poison greatly diluted, 

 and consequently the toxic effects were noted over a longer period than in 

 the feeding tests above. 



