June, 1916. 



American Hee Journal 



sources faster than I could get rid of it, 

 but I would not take a considerable 

 sum for what I have learned. 

 Center Junction, Iowa. 



DR. miller's answer. 



Your experiences are interesting. I 

 do not remember that I tried again 

 putting the diseased brood over ex- 

 cluder, leaving queen below. 



You think it safer, in addition to cag- 

 ing the queen for 10 days, to give her 

 clean combs, putting the old, combs 

 above an excluder. Undoubtedly. Yet 

 those of us who do no extracting can- 

 not take advantage of that plan. How- 

 ever, the proportion of failures with 

 merely caging the queen is so small 

 that it cannot make such a very great 

 difference. 



You also found diseased combs with 

 no unsealed larvie, put two stories 

 above a healthy brood-nest, did no 

 harm. Yet I suspect if you followed 

 that up long enough you would now 

 and then find an exception. For the 

 spores are in that upper story, and 

 while there is little probability that 

 now and then one of those spores will 

 be carried down and fed to a larva, 

 the fact is that so long as there are 

 any spores in any of the combs of a 

 colony, no matter how far removed 

 from the brood-nest, there is always a 

 chance of infection. Indeed, we may 

 go a good deal further than that. Take 

 an apiary in which European foulbrood 

 has been, and suppose it has been so 

 cleaned up that not a spore can be 

 found in any comb, hive, or super in 

 the apiary, and that there is not a dis- 

 eased colony within a thousand miles, 

 yet there is a chance that the disease 

 may break out at any time. For in 

 cleaning up, the bees have carried out 

 millions of spores, and they are scat- 

 tered all over the ground in all direc- 

 tions about the apiary. There is a 

 chance that one of those spores may 

 become attached to the foot of a bee 

 that lights on the ground, to be carried 

 into the hive and by some means get 

 into the breakfast of a baby bee, and 

 there you are with European foulbrood 

 on your hands again. There may be 

 not one chance in a million, but all the 

 same the chance is there. 



Let us return to that plan of putting 

 the diseased brood over excluder, leav- 

 ing the queen below. It appears that I 

 tried it in two cases and it was a suc- 

 cess in both. You tried it, and it was 

 generally a failure, although a success 

 in a few cases. What does that prove ? 

 Not much of anything. It might be 

 thought that it proves it is sometimes a 

 success. Not at all. For sometimes 

 bees clean up of themselves, and the 

 treatment may have had nothing to do 

 in the case. It might be thought that 

 it proves it is sometimes a failure. Not 

 at all. For it may be that the treatment 

 was effective in every case that you 

 tried, but the colonies treated were 

 freshly infected from neighboring dis- 

 eased colonies. 



The moral of this is that, do the best 

 we can, there are chances lurking in 

 wait; but if we stop the feeding of 

 brood for a certain time the chances 

 are so favorable that we may go right 

 on producing crops of honey without 

 worry, fighting the disease whenever it 

 shows itself again, just as we keep on 

 raising good crops of garden stuff with- 



out blubbering over the few weeds 

 that may need the hoe. 

 Marengo, 111. 



Relation Between Apliid Infes- 

 tation and Blight Infection 



BY J. H. MERRILL, PH. 0. 



Assistant Entomologist. Kansas Slate Agricuh 

 turat Experiment Station 



FOR many years it has been custo- 

 mary to put all the blame upon the 

 honeybee for spreading the various 

 formsof blight, commonly called " blos- 

 som blight," "twig blight," "fire 

 blight," "pear blight." It is known 

 that this disease passes the winter in 

 "hold-over" cankers on the limbs, 

 which exude a gummy substance filled 

 with blight bacteria, in the spring. It 

 is also known that in order to damage 

 twigs and blossoms the bacteria have 

 to "be carried by some agency from 

 these cankers to other parts of the tree. 

 As bees visit orchards when in bloom, 

 they were considered to be the agency 

 by which this blight is spread. For 

 years this was accepted without any 

 questioning. 



However, it has been noticed that 

 blight was present in young trees 

 growing in nurseries which never had 

 bloomed and which consequently of- 

 fered no attraction to bees. It was 

 also noticed that new growth which 

 appeared on apple trees after blossom- 

 ing time was blighted and there seemed 

 to be no reason for blaming the bees 

 as they did not frequent such twigs. 



Experiments have been carried on 

 of late to determine what other insects 

 might play a part in spreading this dis- 

 ease. In order for blight to appear on 

 a young tree which never has bloomed, 

 or on new growth twigs, it is necessary 

 for the bacteria to gain an entrance 

 into them. How can this be more 

 easily accomplished than by sucking 

 insects crawling over the cankers. 



later piercing the young growth with 

 their beaks and thus introducing the 

 bacteria into the twig? 



Experiments are now being carried 

 on by the entomologists of the Kansas 

 Agricultural Experiment Station to 

 show what relation exists between 

 aphids and blight infection. At Cor- 

 nell Experiment Station, it was defi- 

 nitely proved that sucking insects, such 

 as the tarnished plant bug, can and do 

 spread the blight. 



In Kansas, observations on the rela- 

 tion of the abundance of aphids to the 

 severity of blight infection have been 

 carried on during the years 1913, 1914, 

 and 1915. In the spring of 1913, large 

 numbers of green aphids were noticed 

 clustering on the unopened apple buds. 

 Several orchardists were induced to 

 spray their trees with a contact insec- 

 ticide to control these aphids. Later, 

 blight appeared quite generally in the 

 apple orchards, but it was noticed that 

 in those in which the aphids had been 

 controlled very little of this disease 

 was present. In 1914, there were very 

 few aphids and very little blight. In 

 the spring of 1915, the aphids again ap- 

 peared in very large numbers, but this 

 year more of the orchardists controlled 

 the aphids by spraying their trees be- 

 fore blooming time with a contact in- 

 secticide. Blight appeared later in 

 every orchard in which the aphids were 

 not controlled, while there was practi- 

 cally no blight in those orchards which 

 had been sprayed with a contact insec- 

 ticide. Jonathan trees are very suscep- 

 tible to blight injury, yet in a large 

 block of these trees, part of which were 

 treated for aphids and part untreated, 

 blight was found only in the untreated 

 portion. 



These observations, which have been 

 carried on for three years, show that 

 there is a direct relation between the 

 aphid infestation and blight infection. 

 It is not the intention to claim here 

 that aphids are the only carriers, as 

 other sucking insects have also been 



FIG. 8J-VIRGINIA WATERLEAF IN AUTHOR'S WILD GARDEN 



