EXPERIMENT STATION BULLETINS. 



301 



BEES AS FEETILIZEES 



Spraying fruit trees in early spring to prevent the ravages of various 

 insects, is becoming very common. Spraying trees while in bloom is 

 likely to poison the nectar and destroy the honey bee. This has been 

 done in several cases. Not only have the mature bees been poisoned, but 

 the brood has also been destroyed. The fact that doubt has been 

 expressed in reference to such poisoning, and the fact that even legislatures 

 have expressed disbelief in the value of bees to horticulturists, led to the 

 following experiments. 



Bees in cages were given foliage sprayed with sweetened water, and in 

 other precisely similar cages, the same sweetened water in which London 

 purple had been mixed in the proportion of one pound to two hundred 

 gallons of water. The bees in the first cages were in no wise affected, 

 while the others were all dead in thirty-six hours and in many cases in 

 twenty-four hours. Thus we have positive proof, both in the field and 

 from laboratory experiments, that bees are very susceptible to the 

 poisonous effects of the arsenities, and that to spray fruit trees while in 

 bloom always endangers the lives of all bees that visit the flowers. In the 

 other experiments we desired to learn how important bees were in the 

 work of fertilization and cross-fertilization of plants. Trees examined in 

 May while in bloom showed twenty bees to one of other kinds of insect. 

 On a rather cold day, such as is likely to occur in time of fruit bloom, 

 hundreds of honey bees were found at work on the apple bloom, while 

 almost no other insects were to be seen. 



In the following experiments the same number of blossoms were counted 

 on each of two adjacent branches on various trees, shrubs and plants. In 

 each case one lot was marked by a tag giving the date of the experiment, 

 while the other was surrounded by cheese-cloth just before the blossoms 

 opened, thus precluding the visits of all insects from this lot except such 

 very small insects as thrips, jassids, etc., which were so small that they 

 would escape notice. After the blossoms withered the covers were 

 removed, and two weeks later examination was made to note the results. 

 The following table gives the results of the experiment: 



Variety. 



Apple 



Crab Apple 



Apple 



Pear 



Cherry 



Strawberries .. 

 it 



Raspberries 



Clover ired).._ 

 (white). 



Unsatisfactory, 



In the case of the strawberries, boxes covered with cheese-cloth were set 

 over the plants. As these set on the ground, of course insects may have 

 come up from the earth. Thus a few insects may have gained access to 

 the flowers, as the plants were necessarily covered for about a month. 



