Pollen! That glorious powdery stuff that makes you sneeze. It may not always be glorious for us, but the bees sure love it and absolutely need it to live, grow, and prosper. If you’re a beekeeper, it’s essential you understand what pollen is, how bees collect it, and what it does for them. You need to know about pollen nutrition in order to do the best for your bees. Follow along and become the pollen nutrition expert that all your beekeeping friends will go to for advice.
Bees gather pollen from flowers. The pollen is male sperm cells from the plant and lives on the anthers, which are part of the stamen. Bees pick this brightly colored stuff up when they visit flowers for nectar and store it in their pollen baskets (corbiculae), located on the tibia of their hindlegs. They bring it back to the hive with them for the colony’s use. Colonies can forage and process around 57 kg of pollen every year.
That’s a lot of pollen!
Pollen is the major source of protein for honey bees, though it also includes fats, lipids, minerals, and vitamins. While there is variation in composition from plant to plant (not all pollen is created equal, nutritionally), generally pollen contains the following:
Honey bees need about 20-25% crude protein in their diets, so having access to plants with higher protein levels is ideal. But, it’s about more than just the protein.
If we travel back to high school science class, we can recall that proteins are comprised of amino acids. There are 10 amino acids that honey bees gain access through pollen collection and that are essential to their nutritional needs. They are as follows:
When bees do not consume adequate amino acids in their diet, it can cause shortened lifespans, less resistance to disease, and poor foraging ability, among other issues. Basically, an underfed colony is a less resilient colony.
Your takeaway as a beekeeper: Honey bees need high-quality protein from a variety of pollen sources so that they consume adequate amounts of the above-listed amino acids.
Now, let’s talk about what happens when the bees bring pollen back to the hive.
While bees are fairly intelligent for how small they are, they don’t know what amino acids are (at least, we don’t think they know) and sometimes they can’t even distinguish pollen from other particulate matter. If you’re a seasoned beekeeper, you may have noticed your workers bringing back anything from coffee grounds to corn dust instead of pollen.
Fortunately, the nurse bees have much more discerning tastes than the foraging bees and will toss the faux pollen to the side once the foraging bees bring it to the hive. That’s right, the foraging workers collect the pollen and bring it back to the hive, where they groom it off of their legs for the nurse bees to process. They get some nectar (sustenance!) from a nurse bee and head back out for more.
Bees cannot digest pollen in its raw form and need to convert it in the hive so it’s usable. Once the nurse bees have access to the raw pollen, they begin to process it. The nurse bees pack the pollen pellets into cells in the comb using their mouths. Enzymes in their saliva mix with the pollen, which causes lactic acid fermentation. This process yields a less perishable, more digestible form of pollen: bee bread.
Lactic acid fermentation: glucose — glycolysis—> 2 pyruvate — fermentation–> 2 lactic acid
Younger nurse bees eat the pollen in order to produce royal jelly, which they feed to all brood up to three days old, and only to brood destined to be queens after three days. Older brood (greater than three days old) get bee bread from the nurse bees.
Nurse bees do, on occasion, feed bee bread to worker bees who are in need of a protein boost. They care for all members of the hive, young and old, through their diligence in creating digestible pollen for their colony.
But, it’s not just up to the foraging bees and nurse bees to keep the colony healthy; as a beekeeper, you can be aware of the nutritional needs of your bees and do what you can to make sure those needs are met.
So, now that you know how important quality sources of pollen are for your honey bees, what’s a beekeeper to do? To keep your beekeeping for the bees, ensure that your bees have a variety of high-quality sources of pollen within their foraging range.
What does that mean? You need to pay attention to what you plant. Here are a few quick tips:
It’s not uncommon for beekeepers to supplement with protein patties or other pollen supplements, but your best strategy is to provide an environment that naturally contains pollen for the bees. If you’re curious if there are specific plants that have higher crude protein, consider the following species:
You can read our blog for information about herbs that honey-bees love to visit, but if you follow our general rules above, you will be in a great position to help your bees. If you do choose to supplement, keep in mind we can’t be 100% certain these manufactured forms of pollen give the bees exactly what they need, but they can be useful in a bind. In fact, if there are good sources of pollen nearby, honey bees may ignore supplements completely.
If you do opt for a pollen supplement, place it near the hive, but not right next to it; you don’t want it to bring pests to the area. Consider making a pollen feeder to keep it close, but still safe for the bees. Ultimately, your responsibility is to keep your bees healthy and safe, and you will need to decide what that means for your individual colony (or colonies).
Honey bees know what they need and have efficient systems in place to ensure they get it. As we’ve discussed, worker bees collect pollen and bring it back to the hive, where nurse bees convert it into its usable form: bee bread. This fermented substance is the primary source of protein for the growing colony.
As a beekeeper, it’s tough to watch your colony struggle or, heaven forbid, perish, but paying attention to pollen nutrition is key to keeping your bees healthy. Next week, we will go through your bees’ preferred source of carbohydrates. Yep, that’s honey.
In the meantime, you can read some of the resources below for an even deeper dive into pollen nutrition.