An interesting paper was recently published, available for reading online.

Tribe, G., Tautz, J., Sternberg, K. et al (2017) .Firewalls in bee
nests—survival value of propolis walls of wild Cape honeybee (Apis
mellifera capensis) Sci Nat 104: 29.   doi:10.1007/s00114-017-1449-5

Additional photos are in a great article at http://www.
naturalbeekeepingtrust.org/single-post/2017/03/24/%E2%80%
9CIt-is-said-that-smoke-calms-honeybees%E2%80%9D

Bottom line, it may be that ancestral bees, as well as some extant races,
were/are adapted to frequent fires.  When they smell smoke, they ignore
colony defense, gorge on honey, and then retreat to the back of the cavity
in hopes of riding out the fire (flash fires in the study area).  The fires
leave the area devoid of vegetation for three weeks, until fire-adapted
plants bloom copiously.  The gorged honey may help the surviving bees
(perhaps with brood cannibalism) to live until the bloom resumes.

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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