GLEANINGS IN BEE CULTURE 



the eoiK-lusion that they are one and the 

 same thing, differing- only because modified 

 by the season and environment. 



Are Bees a Source of Infection in the 

 Transmission of Blight on Fruit- 

 trees ? 



In tliis issue, on page 605, appears an 

 article by Prof. Gossard, in reply to our 

 editorial on page 384, May 15, wherein we 

 held that the professor had drawn some 

 wrong conclusions, and incriminated the bee 

 in a way that hardly seemed warranted 

 from the facts in hand. 



In order that the reader may better un- 

 derstand this discussion, perhaps it would 

 be well to make a statement concerning 

 blight as we find it on pear, quince, and 

 apple-trees, and variously called pear- 

 blight and twig-blight. The latter rarely 

 goes beyond the current year's growth on 

 apple-trees, and disappears the next year 

 because it does not live over as it does on 

 the diseased Avood of the pear and quince, 

 or at least that is the generally accepted 

 opinion. Blight, thei'efore, is not to be fear- 

 ed to any extent on apple-trees, but it may 

 be the ruination of whole pear-orchards. 

 The only remedy is thoro pruning and cut- 

 ting oi¥ the diseased portions. Very little 

 attention need be paid to the twig-blight on 

 apple-trees except to prevent this general 

 source of infection to pear or quince trees. 



RefeiTing to the article of Prof. Gossard 

 in this issue, we are very glad to give this 

 space, not only because he stands high 

 among our entomologists, but because we 

 believe him to be perfectly fair. It is evi- 

 dent that we misunderstood his viewpoint, 

 because he says if he had to make a choice 

 between the extermination of the bees and 

 the sacrifice of the two species of fruit 

 (apples and pears) he would render his de- 

 cision in favor of the bees, and then make 

 shift to other fruit, of wliich there is plenty 

 in the world. This shows that he is a very 

 warm friend of the bees. 



Scientists are not all agreed as to how 

 blight is disseminated. At one time it was 

 thought that bees were the main distributors 

 of it, because if they visit the blossoms of 

 fruit-trees containing the bacteria tliey 

 could carry it to healthy blossoms. While 

 this is true in part later investigation seems 

 to show that biting and sucking insects 

 piercing the tissue of the twigs that are 

 diseased can and do carry the infection 

 when they bite into healthy trees. It has 

 been determined that in the early spring 

 months blighted limbs which had been al- 

 lowed to remain over winter exude a watery 



substance containing thfs? bacteria. The 

 inference has been that the bees would take 

 np these juices, carry them to the hive, and 

 then again to the field. Any one who knows 

 anything about bees knows that they would 

 have no occasion whatever to visit trees 

 unless the trees ivere in hloom; and the very 

 fact that young pear-tree orchards (which 

 we have seen in California, and which never 

 bloomed), were badly blighted, would indi- 

 cate that bees, at least, were not the carriers 

 of the infection. Indeed, the strong prob- 

 abilities are that the bark biting and suck- 

 ing insects are the main cause. 



Prof. Gossard says in this issue that both 

 fruit-growers and beekeepers alike agri'ee 

 that the blossom-blight does not appear to 

 a great extent until some time after the 

 blooming season has opened. He seems to 

 have the impression that they might carry 

 it, after the trees are out of bloom. Any 

 practical beekeejoer could inform him that 

 bees do not visit trees or plants unless when 

 the trees are in bloom, such bloom having 

 either pollen or nectar to offer. Unless the 

 blossoms are badly blighted in the first 

 place, which thej^ will not be in the early 

 spring, as we understand it, they would not 

 be likely to carry any blight-germs; and 

 even if they do carry them to the hive, they 

 could not live long enough to do any harm. 



If we understand the theory of blight 

 transmission, where and how it affects the 

 trees, it would seem, in view of the evidence 

 in hand, such evidence as is furnished here 

 bv Prof. Gossard and others that our 

 bees rarely carry any blight-germs. It is 

 conceivable, however, that the birds might 

 come in contact with the watery substances 

 containing the bacteria that caused blight 

 and carry it from tree to tree. Ants and 

 other insects that crawl over the tree and 

 over portions that are diseased could very 

 easily carry it to trees that are healthy. 

 Bark biting or sucking insects could like- 

 wise do it, and do do a large part of it if 

 the testimony of careful men is correct. 



To summarize, bees do not visit trees 

 except when the trees are in bloom. They 

 would have no occasion for crawling over 

 the bark of infected trees, and never do like 

 ants and other insects; neither could they 

 nor would they bite into the bark, and never 

 do they have occasion to suck the juices 

 from the bark. The very strong testimony 

 offered by Prof. Gossard in favor of the 

 bees would condone for all the mischief that 

 might be laid to their door. 



We are not denying that bees may trans- 

 mit bliglit from diseased to healthy blos- 

 soms; but as the bloom is rarely infected 

 we may infer that bees seldom carry blight. 



