Ari Seppala said:

> Havent' seen any studies about spreading diseases by hive tool or by 
> gloves. Has someone else seen ?

I think your comments are quite correct.

"At Ottawa, experimental inoculations (Gochnauer and L'Arrivee, 1969b)
were tested in an apiary with uninoculated healthy colonies located
adjacent to the inoculated ones to detect cross-contamination of colonies.
Although subject to routine management of checking for queenlessness,
stores or need for supering , uninoculated check colonies did not develop
infection, which suggests that spore transfer by drifting bees, contaminated
hive tools, or other equipment is not always sufficient to transfer 
infection
from diseased to healthy colonies"
regarding biological control of AFB from Hive and Honey Bee

Goes on to make exactly your point about comb transfer being main vector.

Regards
Stan 

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