Agriculture Reference
In-Depth Information
Over the succeeding decades, however, von Frisch's theories were constantly challenged
by scientists who believed that the bees found the food by flying downwind of the
odour plume and that all that the returning forager imparted was the odour. What was
questioned about the Frisch theory was whether bees could decode the dance because
scientists did not believe observing bees with such small brains could actually follow
the instructions.
New tests carried out at Rothamsted in the UK, however, have shown that von Frisch
was right all along. Radar has helped to resolve this long-standing controversy, and
the scientists found that the famous waggle dance contains information about the
whereabouts of nectar, just as was originally proposed in the 1960s.
Radar tracking effectively proved the bees do follow waggle-dance instructions. The
scientists fixed radar transponders to bees who had watched the waggle dance to track
their route to the food source, and it was found they flew straight there. To double
check, bee recruits were taken to release sites 250 m (820 ft) away from the hive. These
bees flew to where the feeding site should have been had they not been displaced,
showing they were following the dance instructions accurately. The scientists found
that this was very strong supporting evidence for the von Frisch hypothesis because, in
this case, there was no possibility the bees were following regular routes or any odours
the dancer might have left in the air.
The worker's lifespan
All in all, a worker bee's lifespan varies according to the time of the year. During
summer, the average lifespan is 15-38 days whereas, during winter, it can be 140 days
or more. This variation is probably due to environmental factors - she will work hard
during the summer weather - and also to nutrition. During the winter months she will
not work much and will live off stores in the hive and body fat built up prior to the
winter period.
Worker bee genetic variation
The worker bee, therefore, changes her duties according to a time schedule, but the
situation is more complex than this. For example, at a given stage in their development,
not all workers will be needed as undertaker bees, removing dead bees from the hive. So
