The 'bumblebees can't fly' lie › Dr Karl's Great Moments In Science (ABC Science)
This problem of how insects fly was so hard to solve, that the mystery was solved only in the last 20 years.
As insects flap and rotate their wings, vortices (or spirals) are
created on the leading edge of their wings. These vortices stay 'stuck'
to the insect wing (unlike the vortices created by aeroplane wings,
which slide off). These vortices then produce lift which keeps the
insect airborne.
To keep themselves aloft, fruit flies sweep their wings through a very large angle (145 to 165 degrees).
But getting back to bees, some species of bees have rather
shallow strokes (less than 130 degrees). But to compensate, the bees
have a very high beat frequency (230 per second).
Bees have a special trick to increase their power output
enormously. They greatly increase their stroke amplitude to 190 degrees,
but increase their beat frequency only slightly to 235 per second
