Native Bee Nutrition
Excerpted from: How to handle robbing in your beehive
Native bees, like any other animal, require essential nutritional ingredients for survival and
reproduction. Our native bees require carbohydrates (sugars in nectar or honey), amino
acids (protein from pollen), lipids (fatty acids, sterols), vitamins, minerals (salts), and water.
Additionally, these nutrients must be present in the right ratio for native bees to survive and
Pollination syndromes are suites of flower traits that have evolved in response to natural selection
imposed by different pollen vectors, which can be abiotic (wind and water) or biotic, such as birds,
bees, flies, and so forth. These trait includes flower shape, size, colour, odour, reward type and
amount, nectar composition, timing of flowering, etc.
For native bees, these are the typical characteristics:
• Color: Bright white, yellow, blue or UV
• Nectar Guides: Present
• Odor: Fresh, mild, pleasant
• Nectar: Abundant, somewhat hidden
• Pollen: Limited, often sticky, scented
• Flower Shape: Shallow, landing platform, tubular
How well do you understand pollinator color preferences? Try:
Pollinator Flower Color Preferences
Like other animals, native bees need carbohydrates as an energy source. All carbohydrates
are first converted to glucose, the fuel in nearly all cells. Carbon dioxide and water
are created as by-products. Aside from being used as an energy source, glucose can also be
converted to body fats and stored. A native bee needs 11 mg of dry sugar each day.
Nectar is the main source of carbohydrates in the natural diet of native bees. Sugar concentration
in nectar can vary widely, from 5% to 75%, although most nectars are in the range of 25% to 40%.
A native bee uses her proboscis to suck up nectar from flowers and stores the
liquid in her crop.
The crop is a specialized part of the digestive system, and has a structure between it and the
midgut, where digestion takes place. This structure can let some nectar in
when the forager needs energy on its way home.
Pollen provides bees with protein, minerals, lipids, and vitamins. All animals need essential
amino acids, which must be obtained externally and cannot be synthesized by animals. Native
bees also need the same 10 amino acids as other animals, including humans. These amino
acids are obtained from pollen .
Native bees do not intentionally carry out pollination; it is the unintended result of the bee’s
travels. Pollen clings to the branched and sticky hairs of the bee's body, and is rubbed off as
the bee walks or flies from one blossom to another. Native bees carry pollen in order to transport
it back to their nests. Pollen is stored in various forms, usually for feeding to the bees' young after
they hatch. In most wild bee species, the females are responsible for carrying and storing pollen.
Males of many species drink nectar from flowers, but lack attributes that allow them to transport
pollen efficiently. Female bees of varying species have evolved singular methods of transporting
pollen. Female bumble bees, for example, carry pollen in baskets called corbiculae.
A corbicula is made up of hairs blended together to form a concave shape.
Most wild bees lack pollen baskets. Instead, many wild female bees have specialized leg hairs called
scopae that are particularly long or sticky. Often, the hairs on bees' legs, bodies and
faces have a slight electrostatic positive charge; negatively-charged pollen is thus attracted to the hairs.
A sterol, 24-methylene cholesterol, is common in pollen and is the major sterol source
for native bees. Nearly all insects need to obtain sterol from their diet because of their inability to
synthesize them directly. Sterol is the precursor for important hormones such as molting hormone,
which regulates growth because it is required at the time of each molt. It is not clear what other lipids
are required by native bees, but most likely normal consumption of pollen provides for all the lipid
Like sterol and lipids, the vitamin needs of native bees are satisfied if pollen is abundant.. It is not known
whether micro-organisms naturally present in the alimentary canal of bees may play a role in providing
vitamins and other essential substances.
The mineral requirements of native bees are poorly understood. High amounts of potassium, phosphate,
and magnesium are required by all other insects, and so presumably are by native bees as well. Excessive
levels of sodium, sodium chloride, and calcium have been shown to be toxic to bees. Again, all the
required minerals can be obtained from pollen, although nectar also contains minerals.
Native bees typically collect water from nearby water sources.
Plants had to solve a problem: they needed to find ways to spread their genetic material.
Flying pollinators were nature's solution. Nectar is made as a reward for pollinators.
Take this quick quiz and see how much you know about bees—our favorite essential pollinators
working around the world. This quiz is intended for fun, in a random-facts-can-be-cool kind of way.
Spring begins andhungry pollinators are on the wing, looking for food. From
the moment emerge in spring to the time that they hibernate or migrate in the fall, pollinators
need to eat.