There are three main food groups: carbohydrates, protein and fats. We humans take all three from a variety of sources. Insects and honey bees in particular have the same needs. They obtain carbohydrates from the nectar and store it as what we call honey. This is their energy giving food. They also need proteins, particularly when they are raising brood. Pollen contains protein as well as carbohydrates and fats.

Insects often have a symbiotic relationship with plants. Many plants produce nectar to encourage an insect, in our case the honey bee, to visit and to incidentally carry pollen off to a neighbouring plant of the same species. The plants depend on the insects to facilitate fertilisation and thus enable the production of seed. In exchange the insect can obtain two types of food, nectar and protein rich pollen. On any one flight it usually collects either nectar or pollen but not both. Honey bee anatomy is designed to gather pollen incidentally on plumose hairs thus transferring it to the stigma of the flower. If a bee wants to take the pollen back to the hive the bee stores the pollen in pollen baskets. Along with an electrical charge, pollen is covered with pollenkitt which makes it sticky and easy to store on the corbiculae (pollen baskets).

A single colony is said to consume between 17 and 34 kg of pollen per year (Crailsheim et al. 1992; Keller et al. 2005). This seems almost impossible to comprehend. Protein consists of amino acids. There are ten amino acids essential for the honey bee, the largest requirement being for leucine, isoleucine, and valine. Proteins are also known as the building blocks of life and are required for the synthesis of tissue so it's particularly important through the metamorphosis from egg to adult. Being vital for brood rearing, we must always ensure that our bees have an adequate supply especially in the early spring when the weather may be inclement.

When beekeepers plant to encourage pollinators they should chose the simple variety of flowers, not the double flowered plants that have been bred by specialist horticulturalists. With these double varieties pollen and nectar access may be impossible for our honey bees. The nectar available to a particular insect is dependent on the length of its tongue. This should be considered if you have the luxury of planting for your bees.

As beekeepers, it pays to delve more deeply into pollen and its qualities. All pollen is not the same. There are two main groups, that which is spread by the wind (and more rarely water) and that which is dispersed by animals, in particular insects. Pollen also varies greatly in size from 5 micrometers, as seen in some forget-me-not, to squash which can have a diameter of 250 micrometers. Most falls between 20 - 80 micrometers. Please note that the unit micron, meaning 1/1000 of a millimetre has been replaced by micrometer.

These two different groups have specific design features. In general wind spread pollen has some sort of aerofoil arrangement whilst insect spread pollen have rough surfaces which attach to the insect freely. Further, pollen grains have different appearances according to whether they are in a dry state or hydrated.

Pollen identification is used in criminal evidence, it's used in paleontology to further understand evolution and of course it's used in the analysis of honey to establish from where the honey may have originated.

Although increasingly DNA sequencing is becoming the method of choice for identifying pollen we beekeepers must be satisfied with light microscopy at 400xs or 800xs magnification. Not for us a scanning electron microscope where the equipment is the size of a small wardrobe. This will mean that we can probably not identify pollen down to subspecies level but we can certainly identify plant genus and maybe species.

Previously we needed to list various attributes of the pollen grain (size, shape, aperture numbers, aperture type, surface, exine section and any other structural features) and then look these qualities up in a table. Now we have available beautifully presented "coffee table books" which make this information more readily accessible.

To this end there is also now the online pollen global network ( see below ) which is an open database of pollen accessible to all. As well as providing more than 1400 reference images it provides microphotographs of pollen yet to be identified. You register on this website and state your organisation. The organisations gain points for every pollen they have helped to identify.

For those of us who prefer a more methodical method of identification we need look no further than Rex Sawyer's book "Honey Identification" which contains the referred to "table of pollen attributes". I would also recommend John White's book "Pollen it's Collection and Preparation for the Microscope". It is more concerned with collecting pollen directly from flowers.

For the beautifully illustrated books go for "Pollen: The Hidden Sexuality of Flowers" by Kessler and Harley or "Pollen Microscopy" by Norman Chapman. The latter also describes making slides from pollen.

Scientific Beekeeping
So called bee bread, different types of pollen stacked one on top of another, within the same cell.
The Global Pollen Project