THE POISONING OF BEES BY ORCHARD SPRAYS 75 



The spray mixture witlioul nicotine sulfate proved sligiitly distasteful to 

 tiie bees. Wiien botli lime-sulfur and nicotine sulfate were left out of the 

 spray and lead arsenate alone was offered the bees, they showed no reluc- 

 tance toward feeding, but clustered about the feeder in large numbers and 

 consumed a liberal amount of the licpiid. 



Within twelve hours after the first liberal feeding, bees began to die in 

 large numbers. The peak of mortality occurred within forty-eight hours, 

 and the colony was completely exterminated in nine to ten days. Except 

 when fed the poison mixture, the bees were kept su])plied with dilute lioney 

 during the run of the experiment. 



The record of daily mortality during the experiment is as follows: 



Date Dead Bees Date Dead Bees 



Dec. 30 1 Jan. 7 140 



31 2 8 220 



Jan. 1 2 9 85 



2 1 10 99 



3* 7 11 62 



4** 17 12 31 



5*** 199 13 7 



6 318 14 2 



Total 1183 



* Pate when honey-spray combination was offered. 

 ** Date when lead arsenatehoney niixttire was offered ( Vi oz.). 

 *** Date when lead arsenatehoney mixture was offered (% oz.). 



From the above it can be noted that in forty-eight hours after the first 

 feeding of the lead arsenate-honey mixttire, approximately 50 per cent of 

 the colon}' was dead. The extended period of high mortality indicates that 

 some of the bees evidently fed upon the poison very sparingly or not at all. 

 During the latter part of the exjieriment, the normal mortality would be 

 expected to be somewhat higher, due to the long period of confinement. 



Relative to.virity of the (liferent materials. 



To determine how toxic each material of the combined sprays was to the 

 bees, nine lots of bees were confined in cages and offered a mixture of 

 honey, and the different insecticides used alone and in combination. One 

 lot was given water alone to serve as a check, and another dilute honey 

 to show normal length of life. 



Bees naturally fed at once on the water and dilute honey mixture. Lead 

 arsenate did not appear to be at all repellant to them. When it was com- 

 bined with lime-sulfur, bees fed readily on it. The combination' of all 

 three materials, however, appeared to be very repellent, and the bees did 

 not begin to feed upon it until after two or three hours. The mixture of 

 lime-siilfur and lioney was taken quite readily; of lime-sulfur and nicotine 

 sulfate was not touched for several hours; while that of nicotine sulfate 

 and honey was very repellent to the bees. They showed a marked aversion 

 toward all combinations containing nicotine sulfate, and for a long time 

 would not feed upon them at all, and even then only sparingly. 



The materials used, dilutions, and reactions of the bees were as follows: 



