298 



mm the lookout to welcome, or succor 

 any travelers who should happen to 

 pass that way. In case any of you 

 readers undertake the journey— il 

 must be done on horses, with a spare 

 animal or two to carry the packs 

 their movements would be tele- 

 graphed ahead and a royal welcome 

 extended to any travelers from the 

 "out side." 



The "Great Australian Desert." as 

 the legend on the maps goes, is not a 

 desert in the sense understood by the 

 man in the street. There are great 

 areas of "prickly spinifex" that can 

 only be penetrated by certain tracks, 

 but there is a "wet" or rainy season, 

 when the great rivers rise and lie- 

 come navigable for many hundreds of 

 miles. 



In the closely settled portions of 

 the commonwealth the beekeeper has 

 to contend with the settler and the 

 grazier who, in their efforts to secure 

 more grass, "ring" the gum trees. 

 That is, they cut a complete ring 

 around the trunk which effectually 

 prevents the tree from drawing any 

 further nourishment below the "ring 

 bark," for it is through the outer lay- 

 ers of fibre, etc., that the sap Hows 

 upward. This does not apply to the 

 conifers, or pine trees, which draw- 

 up their sustenance from the center 

 and increase by the formation of suc- 

 cessive cylinders of primary and sec- 

 ondary bast. 



In the "out back" areas there is lit- 

 tle or no ringbarking. 



Some Observations on Nosema- 

 Disease 



By G. F. White, Bureau of Entomology, 

 Washington, D. C. 



(Concluded from August) 



Queens have been taken from No- 

 sema-infected colonies and introduced 

 into healthy ones, with the result that 

 the colonies remained free from in- 

 fection. Queens have been reared and 

 mated in Nosema-infested colonies, 

 and have recovered from the infec- 

 tion and remained healthy. It has 

 also been seen that colonies show a 

 marked tendency to recover from in- 



AMERICAN BEE JOURNAL 



lection. Examinations have sliown, 

 furthermore, that in diseased colonies 

 it is the exception, and by no means 

 the rule, to find Nosema-infected 

 .[turns. Fear, therefore, that queens 

 are a fruitful source of infection in 

 Nosema-disease, would be by no 

 justifiable. 



Numerous observations strongly in- 

 dicate that the disease is no1 likely 

 to be transmitted by means of drift- 

 ing bees or drones 



While it would seem that, under 

 favorable circumstances, the disease 

 might be transmitted by honey, the 

 I le inees that this is done are much less, 

 probably, than one would at first ex- 

 pect i ertainly, after 2, S or 4 months 

 of spring, summer or fall tempera- 

 ture, the germs would be destroyed 

 and no disease could result from such 

 a source. 



In most instances Nosema-infection 

 does not spread rapidly from the in- 

 fected bees of a colony to healthy 

 ones of the same colony. This state- 

 ment is supported by observations 

 made on the disease, as it is encoun- 

 tered in nature, as well as in experi- 

 mental colonies. During the studies 

 made in 1912, on the apiary already 

 referred to, Nosema-infection was 

 found in all of the colonies, at one 

 time or another, during the year, yet 

 the percentage of infected bees in the 

 apiary diminished from spring to fall. 

 In experimental colonies, as has been 

 said, the colony tends to recover from 

 the infection. Were it true that the 

 infection spreads rapidly from infect- 

 ed bees to the healthy ones of the 

 same colony, the effect of the disease 

 on the colony would be very different 

 from what it is. Less is known con- 

 cerning the transmission of the dis- 

 ease within a colony during the win- 

 ter season. That the spread of the 

 infection, within the colony, during 

 this period, is not great in most in- 

 stances, is evident. 



Likely Source of Infection From 



Nosema 

 The watering place may be a likely 

 source of infection. That bees void 

 their excrements while on the wing 

 and soon after leaving their hive, is 

 certainly true for flights made during 



September 



Australia. The photograph shows that it has 

 almost covered a "rung" gumtree. The gum- 

 trees are killed by a complete ring around 

 the trunk, hut a pine cannot be disposed of 

 that way. 



typically Australian view. I- k I-,,,,] timber! 



irees. In the foreground is a "flat" with a line growlh of lucerne. The buildings 

 in the middle distance are the homestead, stables, etc. The picture was taken in 

 New South Wales. 



the warm days of winter and early 

 spring. Beekeepers will know wdiether 

 this is true for other seasons of the 

 year. The excrement of Nosema-in- 

 fected bees, falling into a body of 

 water, contaminates it with germs 

 and makes it a fruitful source of in- 

 fection. This is true since the para- 

 site remains alive for a considerable 

 period in water. Should the body of 

 water be a rapidly moving one, the 

 chances for infection would be very 

 much reduced. It will be readily seen 

 also that the chances for infection 

 would rapidly diminish as the dis- 

 tance of the water supply from the 

 apiary increased. 



Robbing a Possible Source for 

 Nosema-infection 



i olonies which become weak as .i 

 result of Xosema-disease. naturally 

 are an easy prey to robbers. Definite 

 observation to show that the robbing 

 of hives, which have housed such 

 i olonies. results in infection, has not 

 been made, however. Indeed, when 

 i r , mi sin h colonies have been 

 ins< i led into health} colonies, the 

 a . has noi been 1 1 ansmitted to 

 ,i. j appreciable extent . I hat robbing, 

 in connection with i ase, is 



, i less importance to th< beekeeper 

 than it is in connection with the 

 brood diseases is evident. Until 

 more has been determined, however, 

 , 11 for the practical beekeeper 

 to consider robbing as one of the pos- 



