﻿EFFECTS ON HONEYBEES OP SPEAYING FEUIT TEEES S 



prospect of doing more work along this general line, it is considered 

 expedient to publish the result of the other, earlier work. 



It is now generally admitted that in using arsenicals as a control 

 for the codling moth the best results are in nearly all cases obtained 

 by applying the first spray after most of the petals have fallen, 

 although in commercial orchards where hundreds of acres of trees 

 must be sprayed within a limited time it is necessary to begin spray- 

 ing early in order to finish the work before the calyx cups close. 

 Furthermore, in regions where the trees bloom irregularly, causing 

 a long bloom.ing period for an entire orchard, the trees sprayed vary 

 from those in full bloom to those from which all the petals have 

 fallen. 



Many reports from beekeepers concerning the effect on the honey- 

 bee of spraying trees in full bloom have been published, but only a 

 few systematic investigations have actually been carried on to deter- 

 mine whether or not the practice is injurious to bees. Some bee- 

 keepers believe that the honeybee is damaged slightly, even when 

 the trees are sprayed at the customary time, after at least 90 per 

 cent of the petals have dropped. ISTo careful observations have been 

 reported on this phase of the subject. 



In the hope of reaching definite ansAvers to some of these ques- 

 tions, so long debated, the writers planned and conducted the research 

 here reported. Investigations, extending from 1914 to 1917, were 

 made along three lines : (1) The effect on honeybees of spraying fruit 

 trees in full bloom; (2) the effect on honeybees of spraying the 

 trees at the customary time, after most of the petals have fallen; 

 and (3) a determination of the minimum amount of arsenic required 

 to kill bees in confinement. 



EFFECT ON HONEYBEES OF SPRAYING FRUIT TREES IN FULL 



BLOOM 



PRELIMINARY EXPERIMENTS, WINCHESTER, VA., 1914 



Three small, more or less isolated orchards in full bloom, lying 

 southeast of Winchester, Va., were selected in 1914 for the prelimi- 

 nary experiments. Three strong colonies of bees were installed in 

 each orchard. Twenty-five trees in the first orchard were sprayed 

 with a mixture of 5 ounces of Paris green, 1 gallon of limewater, 

 and 49 gallons of water ; 2.5 trees in the second orchard were sprayed 

 Avith a mixture of 3 pounds of paste lead arsenate, 1 gallon of lime- 

 water and 49 galk)ns of water; and 25 trees in the tliird were sprayed 

 with a rnixtiu'c of" 3 pounds of paste lead ai"senate, 1.5 gallons of lime- 

 -iilphiir and enough water to make 50 gallons in all. 



As a result of these preliminary experiments the following points 

 were ascertained: (1) Bees work e((iiaily as well on trees sj)rayed in 

 full bloom as on unsprayed ones; (2) they do not fly away from the 

 sprayed orchard very much if the orchard is Avell isolated; (3) they 

 are slightly affected when a small oi'chard is sprayed in full bloom; 

 this conclusion is supported }>y observations and by the analyses of 

 the samples collected ; and (4) of the three mixtures nsimedi, the lime- 

 sulphur spray mixture is most siltisfactory for exj>erimental jxii-poses, 

 Ixicause tin; liiMe-sul]jlinr in it sei'\es well as ii. stain, so thiit the mix- 

 ture can be easily seen on the foliage and bloss(mis. Its presence 



