Yesterday I wrote that bees need a continuous supply of flowering plants such that something is always in bloom. I also mentioned that different types of bees prefer different types of flowers. What I didn’t discuss was the importance of pollen variety in the bee diet.
I think it is easier to understand bee nutrition when you compare it to our own. So, just now, I went to the pantry and reached for a can. It happens to be Trader Joe’s 100% pineapple juice in an 8.45 fluid ounce (250 ml) single-serve container. Good enough.
The nutrition facts printed on the side of the can tell me that one serving (the entire can) provides 2% of the daily vitamin A needs of a person who eats a 2,000 calorie-per-day diet. (Those are actually kilocalories, but that is a separate subject and a different blog.)
So, assuming I’m such a person, to get enough vitamin A by drinking just pineapple juice, I would have to drink 50 cans (422.5 ounces) or 3.3 gallons of the stuff. I like pineapple juice, but there’s a limit.
The 3.3 gallons also provides 7250 calories which is 3.63 times more than I need (assuming 2000 per day.) But it doesn’t supply any fat—which is necessary for good health—and doesn’t supply many of the other vitamins, minerals, and trace elements which keep us going from day to day. I certainly would not be very healthy living on pineapple juice alone.
You can think of a pollen grain as a “can” of food. It contains many of the amino acids, lipids, vitamins, minerals, and trace elements a bee needs, but different types of pollen contain different types of “ingredients.” The label on a can of beans will look very different from the label on the juice, just as the “label” on a grain of maple pollen looks different from the one on a grain of aster pollen.
Research has shown that when bees are forced to consume pollen that is low in nutrients they respond by eating more of it. But just as in the example above, they reach a limit. They’re full. They’re stuffed. They simply cannot eat enough of the inferior pollen to satisfy all their nutritive requirements.
Bees lacking in nutritious food are more prone to disease, don’t live as long, and can’t maintain a strong hive. Brood production falls off and eventually a colony will die. So when planning the placement of your hives, remember that the admonition to “eat a variety of foods” applies to them as well as us.