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rWL EFFECTS OF A PHENYL i:sRCURY^>- CO.-IPCUMD OK HONEYBEES 



Beekeepers have had to be on the alert for years to avoid losses of oees 

 tnrough improper applications of sprays or dusts. In some states there are laws 

 prohibiting the applicatirn during bloom of substances harmful to bees. Various 

 writers as Eckert 1935^ 19hU, Knowlton 19UU and Shaw 19I4I and 19UU have presentea 

 data showing the effects of pesticides on bees. 



Two types of applications have been permitted during bloom. Certain fruit 

 tninning sprays have been shovm to have no effects on bees. Sulfur applications 

 have also been allowed. Shaw i9l4.it has shovm that the toxicity of sulfur to bees is 

 not as serious as many other pesticides. 



During this past springy considerable anxiety was expressed in Massachusetts 

 relative to the use of phenyl mercury compounds during bloom. Such compounds have 

 good apple scab control properties. Y\fith the unusually high rainfall, many growers 

 planned to use phenyl mercuries during bloom. Their use had been included in the 

 spray schedule even though no work had been done to determine the toxicity of these 

 materials to bees. Another important point to determine was the possible repellant 

 action of the fungicide to pollinating insects. 



In order to obtain information as to the possible danger of these chemicals to 

 bees some preliminary tests were conducted at the University of Massachusetts. In 

 these tests, bees were shaken from brood frames into sleeve cages. These were then 

 taken to the college orchard. Through the cooperation of the Pomology Department, 

 the services of a sprayer and crew were made available. A phenyl mercury compound 

 (Puratized) was used at the rate of 1 pint of this material in 100 gallons of water. 

 The first cage was fastened to a branch of apple blossoms and leaves. Then the tree 

 was sprayed. This was felt to constitute a severe test of the possible contact 

 action of the chemical. After the spray had dried, a second cage was fastened to a 

 branch bearing treated foliage and blossoms. The bees were exposed to any possible 

 residual action of the material for 20 minutes and then the cage was removed. The 

 third sleeve cage constituted the check. Following treatment, the cages and bees 

 were taken to the laboratory. Food was supplied and daily counts of the mortality 

 was recorded. 



The data on the next page indicate that no or only slight danger to bees 

 resulted from their contact virith the phenyl mercury compound vrhich was tested, 

 ii'oreover, it vras evident from the observation of the behavior of bees in visiting 

 treated blossoms that no repellant action occurred. 



In order to secure more complete information, a second lot of experiments was 

 planned. The bees rrere placed in sleeve cages as already explained, One lot was 

 exposed to possible contact action and a second to residual action. Concentrations 

 of phenyl mercury at the rates of 1 pint, 2 pints and h pints per 100 gallons vrere 

 applied. These concentrations are expressed in the accompanying tables as X, 2X and 

 UX. Following the treatments, the bees were taken to the laboratory and given food. 

 Daily observations of the mortality of the bees were made for a period of ten days. 

 At the end of this period, living bees were killed \vith cyanide to determine the 

 total number in each of the cages. The data obtained are presented in Tables ll and 

 III, 



>- "Puratized" was the phenyl mercury tested. 



