3F 
 53a 
 
 PS5 
 R34 
 
CORNELL UNIVERSITY LIBRARY 
 
PURDUE UNIVERSITY 
 
 Agricultural Experiment Station 
 
 Buli,e;tin No. 247 
 July, 1920 
 
 BEES AND THEIR RELATION TO ARSENICAL 
 SPRAYS AT BLOSSOMING TIME 
 
 Published by the Station ; 
 LAFAYETTE, INDIANA 
 / U. S. A. 
 
I« 
 
 Cornell University 
 Library 
 
 The original of tiiis book is in 
 the Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924062872340 
 
BEES AND THEIR RELATION TO ARSENICAL 
 SPRAYS AT BLOSSOMING TIME 
 
 W. Ay Price 
 
 INTRODUCTION 
 
 Fruit-growers who apply lead arsenate or other arsenical sprays to 
 trees in full bloom have long been accused by beekeepers of causing a tre- 
 mendous death rate of bees from poisoning. Beekeepers and entomolo- 
 gists have noticed the large number of dead bees around sprayed trees and 
 about the hive. Even when they made allowance for death from old age, 
 disease, and other causes, the mortality was abnormally high. Fruit- 
 growers have not been willing to assume responsibility for this excessive 
 death rate, and up to the present time very little in the way of exact data^ 
 has been submitted to support either side of the question. The experi- 
 ments recorded here are an attempt to contribute definite evidence on the 
 subject. 
 
 The foregoing discussion may bring at least two questions to the mind 
 of the reader. Why is a spray applied when apple trees are in full bloom ? 
 Could it not be applied later with just as good results? Pathologists tell 
 us that spraying is necessary to control scab just before the blossoms open 
 and again after the petals fall. The effective period for applying the first 
 spray is only -three days in extent, and for tlje second spray about five days. 
 
 An arsenical is also applied in the first spray to control curculio, and 
 in the second spray for codling moth. The spray for codling moth must 
 be applied before the calyx lobes close, which is from a week to ten days 
 after the blossoms fall. If growers could only adhere strictly to the well- 
 defined time limits mentioned for each of these sprays, the- discussion re- 
 garding bee-poisoning would have to end, for it is a well known fact that 
 bees do not visit trees to any large extent before the blossoms open, or 
 after the petals have fallen. But fruit-growers have a practical difficulty 
 to meet in this connection. They must buy enough high-priced spraying 
 equipment to spray large acreages within the short spaces of time pre- 
 viously mentioned. None of the other sprays during the season is so 
 limited in the effective time ior application. 
 
 When rainy weather or lack of capital for equipment forces the or- 
 chardist to begin spraying while trees are in bloom, the beekeeper naturally 
 becomes concerned about having his bees feed upon poisoned blossoms. 
 And if we assume that such feeding causes the wholesale poisoning of bees, 
 the orchard owner not only causes serious loss to a neighboring beekeeper 
 but he kills the only agent which is effective in fertilizing his fruit blos- 
 soms and thus increasing the set and yield of fruit. 
 
 During the course of a clear, warm day in blossoming season a bee 
 usually makes several trips to the blossoms to gather nectar. If spray 
 material has previously been applied to the blossoms, the assumption is that 
 because of the feeding habit of the bee, it can scarcely avoid gathering 
 poison with the nectar. 
 
 1 Detection of Arsenic in Bees, by B. B. Holland, Journal of Economic Entomology, 
 Vo-l. 9, No. 3. ' 
 
 Spraying with Arsenites vs. Bees, by F. M. Webster, Bui. No. 68, Ohio Agricultural 
 Experiment Station. 
 
It was the object of this experiment to determine definitely whether 
 bees absorbed poison into their systems in this manner, and if so, whether 
 such doses were sufficiently large to be fatal. 
 
 The work was carried on in cooperation with the Department of 
 Horticulture of Purdue University, and the analysis and feeding phase 
 of the work was generally supervised by Mr. H. A. Noyes, Research 
 Chemist, then of that department. 
 
 FIELD OPERATIONS 
 
 Apple trees were caged with screen and cheese-cloth (See Fig. i). 
 When the trees were in full bloom lime-sulphur testing one degree Baume 
 
 Fig. 1. Tree surrounded by a cage having window screen on the top and sides and 
 cheese-cloth on the bottom. A colony of bees is shown near the trunk of the tree. 
 
 and one pound powdered arsenate of lead to 50 gallons of water was 
 applied. Bee colonies were then moved into the cages and observations 
 made on them. Also trees in full bloom in the open were sprayed, while 
 others were left unsprayed. Observations were made on both. Dead 
 bees were gathered from the cages, counted, and analyzed for arsenic. 
 
 LABORATORY WORK 
 
 These experiments naturally divided themselves into three divisions : 
 (i) the ascertaining of the amount of soluble arsenic it took to kill a bee; 
 (2) whether a bee working upon a mixture of insoluble arsenic and syrup 
 would take up the arsenic particles: and (3) whether bees that were found 
 dead near the experimental trees contained arsenic internally that ac- 
 counted for their death. 
 
Fig:. 2. Bee cage used in the laboratory. 
 
 The syrup was a 40 per cent solution of cane 
 sugar. To this was added soluble arsenic, sufficient 
 to give .000581 gram to each gram of syrup. "^ 
 A drop of this was placed on a piece of wax founda- 
 tion, and the whole weighed to one-tenth of a milli- 
 gram. This was immediately taken from the balance 
 and slipped under the cage containing the bees. Very 
 soon (almost instantly) a bee would find it and be- 
 gin feeding. The cage was then raised a bit from 
 the board and placed to one side leaving the bee on 
 the foundation in the open. A glass funnel was 
 then placed over the individual (See Fig. 4) and 
 
 In determining the fatal dose of 
 arsenic we proceeded about as fol- 
 lows : Flying bees were taken in front 
 of the hive by first drumming to 
 cause them to fly densely at that 
 place, then while so swarming, a 
 wire cage (See Fig. 2) was dropped 
 over them on to a smooth wide 
 board, thus trapping them. The 
 cages were then moved into the lab- 
 oratory and placed in a dark closet 
 over night; the bees were fed the 
 next morning. When treated in this 
 way they are easily handled, 
 and feed readily when given the 
 syrup. 
 
 1 Examination of dead bees to determine the presence or 
 absence of arsenic was made by the Gutzeit method. Briefly, 
 the laboratory procedure was as follows: 
 
 One bee that had been treated with sodium hydroxide and 
 nitric acid for the removal of arsenic on the surface of the body 
 was placed in a 'test-tube; a little water, an equal amount of 
 hydrochloric acid, and some potassium chlorate were added, and 
 the test-tube placed in a steam bath. Chlorine was evolved, 
 which breaks down the tissue of the body, thus liberating the 
 arsenic. The contents of the test-tube were then evaporated to 
 near dryness to drive off the free chlorine. The residue was 
 then examined in the apparatus shown in Fig.^ 3, w^hich consists 
 of an eight-ounce bottle (d) and three small tubes and stoppers. 
 In the tube just above the bottle (c) a folded filter paper was 
 placed which had been saturated with lead acetate and dried. 
 The tube above this (b) contained a mass of glass wool sat- 
 urated with lead acetate. The last tube (a) contained a small 
 strip of filter paper which had been saturated with mercuric 
 chloride and dried. 
 
 The contents of the test-tube were now placed in the eight- 
 ounce bottle. To this were added hydrochloritj acid, stannous 
 chloride, ammonium ferric alum, water, and zinc' The zinc and 
 acid cause an evolution of gas, hydrogen sulphid, arsine, etc. 
 The sulphides were caught by the lead acetate, and the arsine 
 was passed on to the sensitized mercuric chloride paper, , When 
 arsine is present, the paper turns yellow; if absent, no change 
 is apparent. Figure 5 shows some tests of bees in the control 
 feeding work when the amount of arsenic taken was known. 
 
 Considerable experience by the operator is necessary before 
 reliable results can be obtained. For this work everything was 
 standardized and unusual pains taken to secure accuracy. All 
 materials used "were frequently tested for arsenic, as this method 
 properly handled is delicate enough to show positive results 
 with much so-called chemically pure acid and zinc. 
 
 Fig. 3. Gutzeit meth- 
 od. D (8-oz. bottle) 
 contains emnlsifled bee 
 and reagents; C con- 
 tains filler paper satu- 
 rated with lead acetate 
 then dried; B contains 
 glass wool saturated 
 with lead acetate; A 
 contains sensitized mer- 
 curic chloride paper. 
 
records kept of the time it lived after feeding and also of the post-mortem 
 examination. As soon as it had finished feeding, the foundation and re- 
 maining syrup were weighed and the amount of syrup- and arsenic com- 
 puted. These records are shown in Table I. 
 
 Tabi,e I. — Showing Grams Syrup Taken, Grams Arsenic Taken, and the 
 
 Number of Minutes Bees Remained Alive After Feeding, 
 
 Also the Post-Mortem Analysis for Arsenic. 
 
 
 
 
 
 Arsenic Anal. 
 
 
 Bee No. 
 
 Gms. Syrup 
 t alien 
 
 dma Arapnifi 
 
 Dead 
 
 
 
 
 taken 
 
 min. later 
 
 # 
 
 
 
 1 
 
 .0638 
 
 .0000371 
 
 150 
 
 * 
 
 
 
 2 
 
 .0244 
 
 .0000142 
 
 110 
 
 * 
 
 
 
 3 
 
 .0173 
 
 .0000100 
 
 175 
 
 * 
 
 
 
 4 
 
 .0085- 
 
 .0000049 
 
 420 
 
 » 
 
 
 
 5 
 
 .0113 
 
 .0000065 
 
 370 
 
 * 
 
 
 
 6 
 
 .0091 
 
 .0000052 
 
 520 
 
 « 
 
 
 
 7 
 
 .0076- 
 
 .0000044 
 
 420 
 
 * 
 
 
 
 8 
 
 .0135 
 
 .0000078 
 
 375 
 
 « 
 
 
 
 9 
 
 .0105 
 
 .0000061 
 
 360 
 
 * 
 
 
 
 10 
 
 .0166 
 
 .0000096 
 
 300 
 
 * 
 
 
 
 11 
 
 .0072 
 
 .0000041 
 
 425 
 
 * 
 
 
 
 12 
 
 .0137 
 
 .0000079 
 
 410 
 
 « 
 
 
 
 13 
 
 .0232 
 
 .0000134 
 
 157 
 
 « 
 
 
 
 14 
 
 .0128 
 
 .0000074 
 
 405 
 
 * 
 
 
 
 15 
 
 .0122 
 
 .0000070 
 
 450 
 
 # 
 
 
 
 
 Arsenic 
 
 in syrup reduced s 
 
 that 1 gm 
 
 . of syrup 
 
 
 
 
 contains .000120 gms. arsenic 
 
 
 
 16 
 
 .0257 
 
 .00000308 
 
 500 
 
 * 
 
 
 
 17 
 
 .0215 
 
 .00000258 
 
 430 
 
 * 
 
 
 
 18 
 
 .0058 
 
 .00000069 
 
 590 
 
 « 
 
 
 
 19 
 
 .0303 
 
 .00000363 
 
 450 
 
 * 
 
 
 
 20 
 
 .0214 
 
 .00000256 
 
 430 
 
 » 
 
 
 
 21 
 
 .0157 
 
 .00000188 
 
 420 
 
 * 
 
 
 
 22 
 
 .0165 
 
 .00000198 
 
 370- 
 
 » 
 
 
 
 23 
 
 .0263 
 
 .00000315 
 
 480 
 
 * 
 
 
 
 24 
 
 .0046 
 
 .00000055 
 
 590 
 
 
 O 
 
 
 25 
 
 .0240 
 
 .00000288 
 
 440 
 
 * 
 
 
 
 26 
 
 .0051 
 
 .00000061 
 
 610 
 
 « 
 
 
 
 27 
 
 .0205 
 
 .00000129 
 
 600 
 
 * 
 
 
 
 28 
 
 .0225 
 
 .00000142 
 
 540 
 
 * 
 
 
 
 29 
 
 .0131 
 
 .00000082 
 
 600 
 
 * 
 
 
 
 30 
 
 .0208 
 
 .00000131 
 
 610 
 
 « 
 
 
 
 31 
 
 .0207 
 
 .00000130 
 
 600 
 
 * 
 
 
 
 32 
 
 .0293 
 
 .00000184 
 
 480 
 
 * 
 
 
 
 33 
 
 .0160 
 
 .00000100 
 
 500 
 
 * 
 
 
 
 34 
 
 .0144 
 
 .00000090 
 
 630 
 
 
 
 
 
 35 
 
 .0120 
 
 .00000075 
 
 670 
 
 « 
 
 
 
 36 
 
 .0329 
 
 .00000207 
 
 660 
 
 » 
 
 
 
 Numbers 16-26 inclusive were fed between 8 40 and 9 :i2 a. m. This 
 gives some idea regarding the rapidity of the feeding process. 
 
 The sign * is used in the table to indicate that the bee gave a positive 
 test for arsenic ; the o sign indicates the opposite reaction. 
 
 It might have been possible to attribute the death of the bees fed with 
 arsenic, considered in Table I, to other causes. For instance, death 
 
might presumably occur as a result of old age, or through injuries received 
 in colliding with the sides of the cage in a desperate attempt to escape. 
 
 Fiff. 4. Part of laboratory apparatus used in the feeding work. 
 
 In order to determine the actual death rate resulting from such 
 causes, 48 bees were placed in a screen cage alongside the poisoned ones, 
 and kept well supplied with unpoisoned syrup (See Fig. 4). None of the 
 bees in this cage died during a period of nearly four days. This was fully 
 three days after all the bees were dead in the cages containing poisoned 
 syrup. At the end of this period, the cage was lifted, and all the bees fed 
 on pure syrup flew away. 
 
 i. 
 
 „ . 7sst& ^>'0/rt S/-it/tJard Aysttrt/e. So/uh'tn 
 
 
 .00000/ a 
 
 f/vs. 
 
 jioeoozo 
 
 .onooote 
 
 
 oooooto 
 
 eooo/io 
 
 OOQOlSO 
 
 oooaxoo 
 
 % 
 
 % 
 
 
 
 
 
 I 
 
 1 
 
 1 
 
 1 
 
 \ '^ 
 
 rse. /tic Tests ^rem y^V/i,;7</../ 7?/»,..« 
 
 
 Slair/( 
 
 /vi'V Bee. 
 
 .ooooooS 
 
 ooooo/x 
 
 
 .ooooea.S' 
 
 ,OOOOOf6 
 
 .oaao/f*. 
 fmt. 
 
 .ooeo%f/ 
 
 fart. 
 
 i 
 
 
 
 
 
 
 
 
 t 
 
 I 
 
 
 
 
 
 
 
 
 it 
 
 i 8 
 
 ' i 
 
 - 
 
 M 
 
 * 
 
 ■» 
 
 ll 
 
 1 
 
 l" 
 
 Fig-. 5. Mercuric cliloride papers sliowing* tests from known amounts of arsenic. Arsenic 
 caused the papers to turn yellow. In the picture it shows dark. 
 
The third syrup (i gm. sol. containing .000063 gra., arsenic — See 
 Table I) was diluted with equal parts of sugar syrup and given ..to seven 
 bees under the cage. A supply was kept near them continuously. This 
 was given them on July 19, 1 130 p. m. At 8 a. m. on July 20 there were 
 four dead and two on their backs ; on July 20, at 2 p. m., there were five 
 dead and two on their backs; at 10:30 p. m. on July 20 all were dead. 
 
 This same syrup (.000063 gms. arsenic per gm. syrup — See Table I) 
 was diluted again. This time three parts of the poisoned syrup was diluted 
 with one part clean syrup. Eleven bees were given the syrup in abundance 
 on July 19, at 2 :i5 p. m. On July 20, at 8 a. m., there were eight dead 
 and one on its back ; at 2 p. m., nine were dead ; and at 10 130 all were dead. 
 
 A third dilution of the .000063 gm. poisoned syrup, was made by 
 adding three parts of clean syrup to one part of the arsenic syrup. This 
 was supplied in the same way as the above to eight bees on July 19, at 
 2 p. m. On July 20, at 2 p. m., one was on its back, all others appeared 
 healthy; at 10:30 p. m., on July 20, one was dead and two on their backs. 
 On July 21, at II :3o a. m., two were dead and three were on their backs; 
 on July 22, at 8 a. m., all were dead. 
 
 Of the 27 bees used as a check on the last three groups, only two 
 died during the period of observation.^ 
 
 In order to see what the efifect of the ordinary commercial arsenate 
 of lead would be, a 40 per cent sugar solution was made containing the 
 equivalent of one pound of powdered arsenate of lead to 50 gallons. It 
 was fed to 26 bees on July 23, at 10:15 a. m. All bees were in one cage, 
 and no individual records were kept. Twenty-five of the 26 died during 
 the night of July 23, and all were dead at 10 a. m. on July 24. A check 
 of 31 carried alongside of this cage showed one dead bee. 
 
 It will be seen from the data given above that the bee is capable of 
 taking into its system at one feeding .063 grams of syrup. This amount 
 of syyup in our first dilution contained .0000371 grams of arsenic, which 
 was the largest dose of poison taken in, these experiments. The bee lived 
 150 minutes after feeding. Another bee with a smaller dose of poison 
 (.0000142 grams) lived no minutes after feeding. The smallest dose 
 administered was .00000055 grams of arsenic, and the bee lived 590 min- 
 utes after feeding. The experiments offer evidence that a very small 
 amount of arsenic is fatal to the bee, and that a bee takes up lead arsenate 
 particles in feeding on a sugar solution having them in suspension. 
 
 It was noticed in the control feeding work that the poisoned bee began 
 to behave abnormally (sick) soon after feeding, usually within 20 to 30 
 minutes. It would drop from the top or side of the cage to the floor 
 buzzing and spinning on its back like a decapitated fly. It seemed unable 
 to right itself and continued to struggle in this way until it finally died. 
 
 1 In all the above experiments arsenic in soluble form was used, because it lent itself 
 to more accurate computation in the small doses given, The commercial arsenate of lead 
 is insoluble in water and nectar, and therefore it was impracticable to use it in these tests. 
 The small particles of arsenate being in suspension or grouped in the liquid prevents equal 
 distribution. A bee feeding on a certain amount of the liquid might take a large amount 
 of the poison particles, whereas another bee taking a like amount of liquid from the same 
 receptacle might take only a small amount of the poison particles. There would thus be 
 no reliable way of computing the amount of arsenic in the doses taken in the control feed- 
 ing experiments. 
 
It may appear from this that the possibility of bees bringing much 
 poisoned honey into the hive is rather remote. Demuth^ has shown that 
 the bee makes on the average about four trips to the field in a day. If 
 this is the case, and if sickness comes in 20 minutes after feeding to a 
 degree that makes it impossible to fly to the hive, it is clear that those 
 unfortunate enough to gather the poisoned material will in most cases bs 
 unable to return to the. hive with their loads. 
 
 Dead and dying bees were found in abundance in the blossoms and 
 flower clusters as well as under the trees in the vicinity of the trees 
 sprayed in the open. This condition was not confined to the sprayed trees 
 alone, but the trees in the immediate vicinity of those sprayed were well 
 littered with dead. In the other end of the orchard, where there were no 
 sprayed trees (See Fig. 8), no dead or dying bees could be found.^ 
 
 Is it not possible that the bees found on and around the unsprayed 
 trees in the vicinity of the sprayed ones secured poison from the sprayed 
 tree, and in further quest for nectar flew to the adjacent trees which had 
 no spray on them, and there became sick and unable to proceed farther ? 
 
 FIELD WORK— First Year 
 
 The first year two trees were caged. Cheese-cloth was used for the 
 four sides, top, and bottom. The trees were of the Jonathan variety and 
 twelve years old. 
 
 On Sunday, May 5, the trees were in full bloom. The next morning, 
 May 6, one of the trees was sprayed with lime sulphur (1° B. or one 
 gallon lime sulphur to 50 gallons of water) and arsenate of lead, one 
 pound to 50 gallons. A colony of bees was moved in and liberated. The 
 other tree was dusted with flowers of sulphur and arsenate of lead (85 
 per cent sulphur and 15 per cent arsenate of lead). A colony of bees was 
 put within its enclosure and liberated. Dead bees were gathered in the 
 cages and data secured as shown in the following table. At the conclusion 
 of this phase of the work (morning of May 10), escape boards were 
 placed on the hives and the bees counted. In the hive in the sprayed lot 
 there were found 3880 living bees, and in the dusted lot there were found 
 4960. This gives a mortality- in the case of the sprayed tree of 13.5 per 
 cent, and in the dusted one 18.6 per cent.* 
 
 1 The following unpublished data are from the writer's notes from one of Demuth's 
 lectures: Experiments were carried on by Geo. E. Demuth, Bureau of Entomology, 
 U. S. D. A., for another purpose which incidentally furnished data concerning the number 
 of trips a bee makes per day in gathering nectar. Six colonies were weighed in the 
 morning and evening each day. The difference in their weights represented tlie amount of 
 nectar gathered that day. Bees ■with and without loads of nectar were weighed and it 
 was found that when nectar was abundant they carried from one-half to two-thirds of 
 their own weight in nectar (four to six m. g.). With this information, knowing the 
 number of bees in the colony and the proportion that go to the fields, it was not difficult 
 to compute the number of trips made each day by each bee. It was found that the 
 average number of trips made was about four; old bees making 2% trips and young ones 
 more than five. These experim.ents were carried on in the midst of large commercial 
 orchards when apple blossoms with much nectar were only four rods away. 
 
 2 This observation was made by Prof. Laurenz Greene, Chief in Horticulture, Purdue 
 Univ. Agr. Exp. Sta. 
 
 3 Twenty-four bees were analyzed that were not treated with sodium hydroxide and 
 nitric acid; 21 of these were strongly positive in the arsenic tests. This indicates the 
 importance of careful treatment with sodium hydroxide, acid, and washing. 
 
10 
 
 Table II. — Showing Time of Gathering and the Number of Dead Bees 
 Taken From the Sprayed and Dusted Trees 
 
 Time ol gathering 
 
 
 No. 
 
 bees 
 
 
 Sprayed 
 
 Dusted 
 
 204 
 
 
 
 240 
 
 175 
 
 
 
 428 
 
 13 
 
 
 
 29 
 
 101 
 
 
 
 279 
 
 11 
 
 
 
 17 
 
 103 
 
 
 
 141 
 
 607 
 
 
 
 1134 
 
 13.5 per cent 
 
 18.6 
 
 per cent 
 
 May 7—8:00 A. M. 
 May 7—7:30 P. M. 
 May 8—8:00 A. M. 
 May 8—3:00 P. M. 
 May 9— 8:00 A. M. 
 May 9—7:00 P. M. 
 
 Mortality 
 
 Table III. — Showing Positive and Negative Tests for Arsenic Obtained 
 
 From the Examination of 210 Bees From the Sprayed Tree. 
 
 Each Bee Is Represented by * or o, the * Indicating a 
 
 Positive Test and the o a Negative Test 
 
 Lot 1 
 
 Lot 2 
 
 Lot 3 
 
 Lot 4 
 
 Lot 1 
 
 Lot 2 
 
 Lot S 
 
 Lot 4 
 
 ♦ 
 
 
 
 ♦ 
 
 
 
 » 
 
 
 
 » 
 
 
 
 * 1 
 
 * 1 
 
 • 1 
 
 # 
 
 
 
 » 
 * 
 
 * 
 * 
 
 * " 
 
 * 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 * 
 
 « 
 
 « 
 
 * 
 * 
 
 * 
 
 * 
 
 * 
 * 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 « 
 
 » 
 » 
 
 * 
 * 
 
 * 
 « 
 
 « 
 * 
 
 * 
 * 
 * 
 * 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 * 
 
 * 
 * 
 
 * 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 * 
 
 * 
 * 
 
 * 
 * 
 
 » 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 « 
 
 * 
 
 * 
 * 
 * 
 
 » 
 » 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 » 
 * 
 
 * 
 * 
 
 * 
 
 » 
 
 * 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 » 
 
 » 
 « 
 
 * 
 * 
 * 
 
 * 
 * 
 
 « 
 * 
 * 
 * 
 
 * 
 
 
 
 
 
 
 
 » 
 
 
 
 
 
 
 
 * 
 
 
 
 * 
 
 
 
 
 
 
 
 » 
 
 
 
 
 
 
 
 
 
 __ 
 
 
 
 * 
 
 25 
 
 25 
 
 50 
 
 29 
 
 24 
 53 
 
 30 
 
 22 
 52 
 
 29 
 
 25 
 54 
 
II 
 
 This mortality cannot be attributed entirely to poisoning. It is rea- 
 sonable to assume that part of these were killed mechanically or died of 
 other causes. To determine which of the dead were poisoned, chemical 
 analyses were made. After the bees were collected from the cages they 
 were taken to the laboratory and treated with one-tenth normal sodium 
 hydroxide, heated to boiling; then enough nitric acid was added to make 
 the solution acid, and this boiled two minutes, washed five times with 
 distilled water, and dried in the oven.^ This treatment was for the pur- 
 pose of removing any arsenic that might be on the surface of the bee. 
 Individuals were then taken from the various lots and analyzed according 
 to the Gutzeit method for determining small amounts of arsenic. The 
 records are shown in Tables III and IV. 
 
 Table IV. — Showing Positive and Negative Tests for Arsenic Obtained 
 
 From Examination pf 216 Bees From the Dusted Tree. Each 
 
 Bee Is Represented by * or .0, the * Indicating a 
 
 Positive Test and the o a Negative Test 
 
 Lot 1 
 
 Lot 2 
 
 Lot 3 
 
 Lot 4 1 
 
 Lot 1 
 
 Lot 2 
 
 Lot 3 
 
 Lot 4 
 
 * 
 
 
 
 * 
 
 
 
 * 
 
 
 
 • 
 
 
 
 » 
 
 
 
 * 
 
 
 
 * 
 
 
 
 « 
 
 
 
 « 
 
 
 * 
 
 
 * 
 
 
 * 
 
 
 « 
 
 
 « 
 
 
 
 
 
 * 
 
 
 « 
 
 
 
 
 
 * 
 
 
 * 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 « 
 
 
 
 * 
 
 
 
 
 
 * 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 » 
 
 
 
 # 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 # 
 
 
 « 
 
 
 
 
 
 
 
 * 
 
 
 * 
 
 
 « 
 
 
 
 * 
 
 
 
 » 
 
 
 
 » 
 
 
 
 * 
 
 
 
 
 
 
 
 « 
 
 
 * 
 
 
 * 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 » 
 
 
 * 
 
 
 * 
 
 
 * 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 * 
 
 
 •» 
 
 
 
 
 
 
 
 
 » 
 
 
 # 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 « 
 
 
 * 
 
 
 * 
 
 
 * 
 
 
 * 
 
 
 * 
 
 
 » 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 » 
 
 
 « 
 
 
 * 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 » 
 
 
 
 « 
 
 
 
 * 
 
 
 
 * 
 
 
 
 
 
 
 
 * 
 
 , 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 » 
 
 
 
 
 
 
 
 
 
 
 
 # 
 
 
 
 
 
 
 
 
 » 
 
 
 
 * 
 
 ^ 
 
 * 
 
 
 
 
 
 
 
 
 
 
 * 
 
 , 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 » 
 
 
 
 
 
 
 » 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 » 
 
 
 » 
 
 
 
 
 
 « 
 
 
 « 
 
 
 
 # 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 * 
 
 
 « 
 
 
 
 
 
 # 
 
 
 
 
 
 
 
 
 
 » 
 
 
 
 
 
 
 * 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 , 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 * 
 
 
 « 
 
 
 
 
 
 
 _ 
 
 
 
 
 # 
 
 
 « 
 
 * 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 « 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 _ 
 
 
 » " 
 
 
 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 « 
 
 
 
 ■ 
 
 « 
 
 
 
 
 
 31 
 
 21 
 
 30 
 
 21 
 
 38 
 
 15 
 
 24 
 
 24 
 
 * 
 
 — 
 
 * 
 
 
 » 
 
 — 
 
 
 
 
 
 
 52 
 
 • 
 
 51 
 
 
 53 
 
 
 48 
 
 1 See note 3, page 9. 
 
12 
 
 FIELD WORK— Second Year 
 
 This year (1919) three trees, of the Jonathan variety and about 12 
 years old, were caged with wire screen on the sides and top and cheese- 
 cloth on the bottom. One was used as a check; the other two were 
 sprayed and dusted with sulphur and arsenate of lead when in full bloom, 
 as described for the previous year. Colonies of bees having 18 pounds or 
 more of capped honey were moved in soon after the spraying and dusting 
 had been done. 
 
 The weather was cold and rainy during a portion of the period of 
 observation (April 30-May 15). Dead bees were gathered in the cages 
 at intervals as follows: 
 
 Tablij; V. — Showing Date of Gathering and the Number of Dead Bees 
 Taken From the Check, Sprayed, and Dusted Trees 
 
 Date 
 
 Cheek tree 
 
 Sprayed tree 
 
 Dusted tree 
 
 April 30 -. 
 
 5 
 
 1716 
 768 
 486 
 427 
 287 
 
 143 
 1770 
 4906 
 2174 
 1675 
 
 959 
 
 45 
 
 May 2 -_ 
 
 1556 
 
 May 7 
 
 1593 
 
 May 10 
 
 451 
 
 May 13 - . 
 
 735 
 
 May 15 . . 
 
 327 
 
 
 
 Living bees at end of 
 obseravtion 
 
 3,689 
 
 15,726 
 19 per cent 
 
 11,627 
 
 7,223 
 69 per cent 
 
 4,716 
 5.536 
 
 Per cent mortality 
 
 46 per cent 
 
 Fig. 6. Tree being examined was one of the several trees to be sprayed in the open. 
 
13 
 
 These three colonies were normal, healthy colonies with plenty of 
 stores at the beginning of the experiment. The bees were not compelled 
 to work the blossom^ for food, and their activities generally were such as 
 would arise from choice. On coming out of the hive the morning after 
 moving into the cages, a goodly number of the bees flew directly to the 
 screen, where they tried to escape. A large number of these, it is reason- 
 able to assume, died as a result of their frantic efforts to escape. It is 
 probable that these were the individuals that showed no trace of poison 
 in the arsenic test. While a large number went to the walls of the cage 
 to escape, a goodly number went to work immediately on the blossoms. 
 
 It was interesting to note that individuals coming from the hive to 
 the blossoms would, after feeding, return to the hive or go directly to the 
 walls of the cage. 
 
 In front of the hives in the 
 sprayed and dusted trees there were 
 piles of dead bees. This may be ex- 
 plained on the basis of death occurring 
 in the hive and the bodies being carried 
 out by the other workers. There were 
 no dead bees in the hives at the end of 
 the experiment. The spot directly in 
 front of the hive and the floor near 
 the walls contained the large majority 
 of the dead bodies, but the entire floor 
 of the cage was always well littered 
 with dead. Those found directly un- 
 der the trees probably died on the 
 blossoms and later fell to the floor. 
 
 As another part of the field work, 
 trees in the open and in full bloom and 
 in the same orchard (See Fig. 6) were 
 sprayed and observed to determine 
 whether bees visited them. It was 
 thought there might be a possibility of 
 a forced working of the sprayed blos- 
 soms by the bees in confinemeiit (in 
 the cages) as they were not free to 
 choose the flowers that they worked. 
 It was a case of visiting the sprayed 
 blossoms or none at all. However, 
 with trees sprayed in the open and 
 with unsprayed trees on all sides the 
 possibilities of forced feeding on these 
 trees was removed, and it is reasonable 
 
 mg. 7. Plan of orchard. Circles rcpre- tO aSSUmC that bcCS, f OUnd OH these 
 
 sent trees. Circles in squares indicate ^rCCS were there by virtUC of their dc- 
 
 caeed trees, and circles witli x's represent . i . , j;i;„„„ 
 
 trees sprayed in the open. Sire, not beCaUSC of imposed COndltlOUS. 
 
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14 
 
 At intervals a survey was made of the sprayed trees and the trees on 
 each side of them, which were essentially the same except that they had no 
 spray on them. Bees actually on the blossoms were counted. The count 
 was made while walking around each tree, and an equal amount of time 
 was given for the count on each tree. The results of these surveys are 
 shown in the following table. The rows of circles indicate three rows, 
 and each circle represents a tree. The daggers show the location of the 
 sprayed trees in the open. Asterisks indicate caged trees, and the figures 
 represent the number of bees counted on the tree. ( Fig. 7 shows plan of 
 orchard). 
 
 Table VI. — Showing the Number of Bees Found on the Sprayed Trees 
 
 in the Open and the Number of Bees Found on the 
 
 Unsprayed Trees About Them. 
 
 
 April 30—11 a. m. 
 
 Two 
 
 additional 
 
 trees 
 
 were 
 
 sprayed 
 
 
 
 on the morning of May G, and recorded 
 
 O' 
 
 *o o» 
 
 as follows: 
 
 
 
 
 *o 
 
 tO' O" 
 
 
 May 6 
 
 —11 a 
 
 m. 
 
 
 0= 
 
 013 o' 
 
 
 
 *0 
 
 Qia 
 
 O' 
 
 0= 
 
 
 
 
 
 *o 
 
 
 
 017 
 
 tO" 
 
 0' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 0* 
 
 
 0' 
 
 
 *0 
 
 
 
 *o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 April 30 — 2 p. m. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o» 
 
 o» 
 
 
 
 
 
 
 
 0' 
 
 *o O^^ 
 
 tO" 
 
 0= 
 
 
 
 
 
 
 
 
 013 
 
 0^ 
 
 
 
 
 
 
 
 *o 
 
 tO» 0' 
 
 
 
 
 
 
 0* 
 
 0^ O' 
 
 
 May 6 
 
 —3 p. 
 
 m. 
 
 
 
 
 
 
 *o 
 
 QIT 
 
 012 
 
 0' 
 
 
 
 *o 
 
 
 
 QIS 
 
 toi* 
 
 0' 
 
 
 May 2—2 p. m. 
 
 
 
 
 
 0= 
 
 0' 
 
 0" 
 
 
 
 
 
 
 
 
 
 
 
 
 
 o« 
 
 *0 0" 
 
 
 
 
 
 
 
 
 
 
 
 *o 
 
 tO» Oil 
 
 
 
 
 
 
 
 
 
 
 
 0= 
 
 0= 0= 
 
 *o 
 
 
 
 
 
 
 
 
 
 
 
 o» 
 
 o» 
 
 
 
 
 
 
 
 Trees sprayed again May 3 — 2 p. m. 
 
 to* 
 
 0= 
 
 
 
 
 
 
 
 Count made 30 minutes later. 
 
 Qi 
 
 0= 
 
 
 
 
 
 
 
 
 
 
 May 7- 
 
 -10 a. 
 
 m. 
 
 
 012 
 
 *o 0* 
 
 
 
 *o 
 
 010 
 
 QIC 
 
 0* 
 
 *0 
 
 tO" 01= 
 
 *0 
 
 
 
 o» 
 
 to' 
 
 Qi 
 
 O'" 
 
 O" o« 
 
 
 
 
 
 012 
 
 O" 
 
 0= 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 May 3 — 3 p. m. 
 
 *o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 O" 
 
 *o O" 
 
 
 
 
 
 
 
 
 
 
 
 
 
 0° 
 
 O' 
 
 
 
 
 
 
 
 *0 
 
 tO» O" 
 
 tO' 
 
 0= 
 
 
 
 
 
 
 
 O' 
 
 0^ 0' 
 
 QIO 
 
 QIS 
 
 
 
 
 
 
 
 It is seen from these surveys, a part of which were made by disin- 
 terested and impartial persons who did not, at the time, know the purpose 
 of the count, that the bee does not avoid sprayed trees. There were 245 
 trees in the orchard (Fig. 7), and all were available to the bee except the 
 three that were caged. If there had been any discrimination against the 
 
15 
 
 ipray, there certainly would have been no bees found on the trees so 
 treated. 
 
 As a matter of more definite record bees were taken while working 
 the blossoms of the sprayed trees. This was done by pinching off the 
 flower cluster and dropping it with the bee on it into an insect net. Seven- 
 teen bees were gathered in this manner by the writer from one of the 
 sprayed trees in 25 minutes. Later in the day three of us gathered 36 in 
 30 minutes under the same conditions. 
 
 Soon after gathering these two lots, they were taken to the laboratory, 
 placed under a wire cage, and given clean (containing no arsenic) syrup 
 and observed. 
 
 At the same time 20 bees were taken from the check hive in the caged 
 experiment and run alongside these as a check. 
 
 The results here are very significant. They show the 17 bees gath- 
 ered at II a. m. to be dead at i p. m. of the same day, and also the 36 
 gathered between three and four o'clock were all dead at 8 p. m. of the 
 same day. The check of twenty were all alive the next day at noon, and 
 ^vhen liberated flew away. 
 
 Chemical analyses were made of all of the dead, and the records show 
 that 48 of the 53 gave a strong reaction to the test for arsenic. (At the 
 name time 20 worker bees and six drones from the check hive were an- 
 alyzed and no arsenic was found in any of them.) Five gave negative 
 results. This might be explained on the basis of the amount of arsenic 
 being so small, yet fatal, that it escaped our test. See Table I. 
 
 Since the Gutzeit method, which is considered a delicate test, failed 
 to show a reaction for arsenic with these five bees, it is obvious that an 
 extremely small dose of arsenic may cause the death of a bee. It is not 
 likely that the five bees showing the negative test could have died from 
 natural causes, since there were no deaths from the check lot of 20 bees. 
 
 The general conclusion which may be drawn from this experiment is 
 that a sufficient amount of poison is to be found in lead arsenate or other 
 arsenical sprays applied to the blossoms to cause a tremendous death rate 
 of bees. SUMMARY 
 
 1. The Gutzeit method of determination of arsenic appears to be 
 sensitive enough for most doses that kill bees ; however, it is believed that 
 some very small fatal doses may escape detection. 
 
 2. A very small amount of arsenic (less than .0000005 grams, as 2O3) 
 is a fatal dose for a bee. 
 
 3. The time required to kill the bee with arsenic depends upon the 
 size of the dose. Some expire within one and one-half hours from the 
 time of administration of the poison, others linger on for a period of five 
 or six hours. Most of those observed to die from a dose gathered in the 
 field did so within three hours. 
 
 4. Bees work freely on sprayed tree's in the open, even when there 
 are unsprayed trees all about. 
 
 5. The morta:lity in the check cage was 19 per cent, as compared with 
 69 per cent in the lime-sulphur-arsenate of lead sprayed cage, and 49 per 
 cent in the sulphur -arsenate of lead dusted cage. 
 
 6. For the sake of the bee, fruit trees should not be sprayed while 
 in full bloom.