40 CIRCULAR 867, U. S. DEPARTMENT OF AGRICULTURE 



Nectar from the honey stomach of bees visiting dinitro-sprayed 

 blossoms was collected by Goble 4 and upon analysis found to be com- 

 pletely free of dinitro material. This would seem to indicate that the 

 nectaries were protected from the spray, and there was little chance 

 of damage to brood or young adult bees in the hive from nectar 

 collected from sprayed orchards. 



When building up food reserves in the hive, bees gather and store 

 pollen on which such poisons as arsenates have settled. Arsenate 

 contamination of stored food is known to be very destructive to the 

 brood. In the orchard observations made by Dyce (9), no bees were 

 found collecting pollen from dinitro-sprayed bloom. These sprays 

 kill all pollen immediately upon contact, and green or unripe anthers 

 shrivel and dry up before shedding pollen. Such pollen is apparentlv 

 unattractive to bees or difficult for them to collect. Goble 4 induced 

 caged bees to collect pollen from a small bouquet of dinitro-sprayed 

 apple flowers placed in the enclosure after the spray dried. The 

 pollen pellets were removed from the bees and analyzed. Only an 

 insignificant trace of dinitro was found, about 0.002 p.p.m. 



To make further observations on the colony under orchard condi- 

 tions, Goble and Patton (15) placed two hives of bees in a block of 

 trees that were to be thinned with a dinitro spray. The complete 

 brood was mapped on cellophane prior to the spraying and again 4 

 days after the application. Careful comparison of these outlines 

 showed that no damage was done in this instance. 



Dyce (9) collected bees from blossoms that had recently received 

 dinitro sprays, and their mortality was compared with bees collected 

 from unsprayed dandelions and other floral sources. The collected 

 bees were placed in wire cloth cages and fed sugar sirup. No signifi- 

 cant difference in the death rate was recorded among the bees exposed 

 and those not exposed to the dinitro-sprayed bloom. 



Writing on the subject of "Bees and Pollination Problems/' 

 Webster, Teleford, and Menke (43) state. "While blossom-thinning 

 sprays are used to an ever-increasing extent in the Pacific Northwest, 

 there have been no reports of widespread losses to bees brought into 

 orchards during fruit bloom." 



Following several years of careful orchard observations by apicul- 

 turists in the State of New York during which no significant loss of 

 bees could be attributed to dinitro thinning sprays, beekeepers and 

 fruit growers mutually agreed to a modification of the existing New 

 York State law to permit the use of dinitro sprays during the blossom- 

 ing period. This new regulation, administered by the State Com- 

 missioner of Agriculture and Markets, became effective in April 1948. 



While no loss of bees has so far been observed in colonies located 

 in orchards where these thinning sprays have been used, laboratory 

 tests indicate that it would be unsafe to assume that losses never 

 occur. Conceivably, very dry weather during the bloom should 

 result in the most favorable conditions for possible damage. Under 

 such circumstances bees collect water during the early morning from 



4 Goble, G. J. the mode of toxic action of dinitro compounds on the 

 honeybee (aphis mellifica linn.). 1945 [Thesis on file in the Everett 

 Franklin Phillips Beekeeping- Library, Cornell University. Ithaca, X. Y.] 



