26 NEBRASKAland • AUGUST-SEPTEMBER 2017
generalist in their flower preference,
feeding upon a wide diversity of
flowers. They lap up nectar with long
tongues and collect pollen on their fuzzy
bodies. Periodically, a foraging bee will
wipe pollen from its body onto modified
structures on their back legs, called
pollen baskets, where they store the
pollen until returning to the nest.
Bumblebees are one of the few
groups of bees that can perform
"sonication," or "buzz pollination."
Some flowers hold their pollen tightly
enough that simply rubbing against the
anthers doesn't remove much of it. A
bumblebee will grab onto the flower
and rapidly vibrate its flight muscles,
achieving a sonic resonance that
dislodges the pollen onto the bee.
Because only bumblebees and a few
species of solitary bee can easily access
the pollen, they are more likely than
other bees to visit flowers that require
buzz pollination. The plant benefits
because it loses little pollen except
to bees that are likely to visit another
flower of the same kind. Among
others, many members of the Solanacea
(nightshade) family benefit from buzz
pollination, including ground cherries,
nightshades, horsenettles, and buffalo
bur, as well as tomatoes. Because of
their special ability, bumblebees are
commonly used by tomato growers in
commercial greenhouse operations.
The fuzzy bodies of bumblebees help
them collect pollen, but also insulate
them against cool weather. In addition,
though, bumblebees can shiver their
strong flight muscles, and warm their
body temperature up enough to fly. This
allows them to fly in temperatures as
low as 40 degrees Fahrenheit – lower
than many other bees and other insects.
A queen bee can use the same shivering
technique to keep her eggs and larvae
warm during cool spring temperatures.
Four of Nebraska's bumblebees
are "cuckoo bees" and follow a very
different lifestyle from the others.
Cuckoo bees don't collect their own
Carolina horsenettle holds its pollen
tightly enough that most bees have
difficulty accessing it, but bumblebees
can shake the pollen loose via buzz
pollination.
Conservation of
land to row crop
agriculture has left
pollinator habitat
restricted to field
edges and corners
in many parts
of the country,
making foraging
more difficult.
