Pollination is enhanced by the pollen that sticks to the hairs of the bee’s body. This pollen adheres easily, and when the bee brushes [...]]]> No, no. I meant they wear what they eat. Imagine going to the store for peanut butter and coming home slathered in the stuff. That’s what bees like to do.

Pollination is enhanced by the pollen that sticks to the hairs of the bee’s body. This pollen adheres easily, and when the bee brushes against the stigma of another flower, the pollen is just as easily released–all of which insures pollination will occur. On the other hand, the pollen stuffed into the honey bee’s corbiculae forms a hard pellet. Pollen stuck together in these tight packages is essentially unavailable for pollination.

Flowers compensate for this loss–and other natural losses–by producing huge amounts of pollen. It is not unusual to see pollen coating the surfaces of cars, ponds, pools, and lawn chairs. Sometimes clouds of it waft from trees and shrubs when the wind blows. The amount the bees pack out to the hive is trivial compared to the amount produced.

If a bee comes back to the hive covered in pollen, she stuffs the pellets into the comb and other bees assist her in grooming away the rest. This bonus pollen is mixed with nectar and stored in cells just like the pellets. Nothing goes to waste.

Rusty

But like most flowers that have been highly manipulated by plant breeders, [...]]]> This question has popped up several times recently, probably because daffodils are in bloom this time of year. Based on the fact that daffodils have large showy flowers, I assume that sometime in the distant past daffodils were pollinated by insects—probably bees.

But like most flowers that have been highly manipulated by plant breeders, daffodils are no longer particularly attractive to insects. The reason for this is simple. When it comes to ornamental flowers, plant breeders select for beauty. Daffodils, in particular, are selected for the color of the flower, the symmetry of the flower, the angle of the flower (does it face up or down), the size of the flower, and other arbitrary characteristics that daffodil judges look for.

In selecting for these characteristics—and crossing them with individuals with other favorable characteristics—plant breeders have been able to produce an amazing variety of daffodils that run the gamut from white to yellow to orange to pink. Some of them are very beautiful and prized by collectors and flower aficionados alike.

Daffodil breeders hand-pollinate the flowers they want to cross and, if all works well, they will get a few seeds from each cross. These seeds are planted and tended for many years—I believe the average is about seven—before the bulb is large enough to produce a flower. Only then does the breeder get to see the results of his work. Once a flower is developed that the breeder wants to keep, it is reproduced by asexual reproduction—that is, the bulbs divide and produce new bulbs.

What you lose in this process are many of the characteristics that made the flower attractive to pollinators in the first place. By selecting only for beauty, for example, you may lose fragrance, sweet nectar, nutritious pollen—or any number of things that the pollinators liked.

Years ago, as a member of the Oregon Daffodil Society, I had the good fortune to meet one of the world’s foremost daffodil breeders. I asked her why she wasn’t worried about all her carefully recorded crosses becoming “contaminated” by pollen that might be carried by wind or animal pollinators. I was intrigued to learn that this wasn’t considered important because very rarely will these highly-bred flowers cross without human intervention.

This loss of pollinator-attracting features is not unique to daffodils but happens in all sorts of flowers from roses to pansies. It is the main reason why people interested in planting native bee habitat or wild pollinator habitat are encouraged to plant either native species or heirloom species that have not been highly manipulated. If you are unsure of a plant’s history, there are certain earmarks that point to intensive breeding. These include very large flowers, variegated flowers, flowers of unusual color, great size, long blooming period, or flowers known as “doubles” or “triples” with multiple sets of petals.

If you are trying to plant for pollinators, remember that many of the gardening catalogs mark the varieties that are attractive to pollinators. Also, stay alert when you see local plants that attract large numbers of pollinators—perhaps you can find the name of the variety from the owner or ask for a cutting or find out where the seed came from.

The important thing to remember is that the flowers most attractive to humans are often not those most attractive to pollinators.

Rusty

Daffodils in vase. Photo by the author.

The practice is used where the crop to be pollinated is either not a honey bee favorite, or when it happens to be in bloom at the same time that other [...]]]> Pollination saturation is the practice of flooding a crop with an overly-large number of honey bee colonies in order to assure adequate pollination.

The practice is used where the crop to be pollinated is either not a honey bee favorite, or when it happens to be in bloom at the same time that other nearby crops—those more favorable to honey bees—are also in bloom. The extra-large population of bees will not find enough forage without working the non-favored plants as well as the favored ones.

For example, blueberries are not a favored plant although honey bees will forage on them if nothing else is available. But if the farmer next door is growing cabbage seed, the honey bees will abandon the blueberries in favor of the cabbage. To assure good blueberry pollination, the blueberry farmer is forced to bring in extra colonies of bees.

Pollination saturation is also used in alfalfa, ladino clover, alsike clover, cranberries, and standard kiwifruit. Its use has become more frequent as the number of native pollinators has decreased and the number of monoculture crops has increased.

Think about bees if you will be eating broccoli, Brussels sprouts, cabbage, [...]]]> Thanksgiving Day in the United States is traditionally celebrated with an over-sized meal based on a stuffed turkey. Since the turkey always takes center stage, many refer to it as “turkey day.” However, to be fair we should call it “bee day.”

Think about bees if you will be eating broccoli, Brussels sprouts, cabbage, cauliflower, squash, turnips, avocados, eggplant, or leeks. Does your stuffing contain sunflower seeds, onion, or parsley? Will you be having cranberry sauce or blueberry muffins? Or how about pickles?—cucumbers, dill, and garlic are all pollinated by bees.

Do you see any carrots or celery? The seeds needed to plant these crops required pollination by bees as well. And the tomatoes were helped along by bumble bees.

Do you have a fruit bowl on the table? Does it have oranges, tangerines, plums, or persimmons? And what about those mixed nuts, including almonds, cashews, and macadamias? Do you have a cheese plate that includes a wedge of honey and crackers with caraway seeds?

And if your pumpkin pie contains pumpkin, allspice, nutmeg, or cinnamon, you can thank the bees for every one of them. And besides apples, your apple pie may contain all those goodies as well as currants and a piece of cheddar cheese on the side.

That’s right. You can’t forget the dairy cows that ate clover and alfalfa, the seeds of which were produced by bees. The milk from those cows provided the butter, sour cream, yogurt, whipping cream, half and half, and all the cheeses that went with the rest of the meal.

I know I’m forgetting something important, but you get the picture. When you sit down at your food-laden table to give thanks for everything we have, take a moment to give special thanks to the bees. Without them, Thanksgiving dinner would not be the same.

Rusty

Plants can reproduce [...]]]> Pollination is necessary for the sexual reproduction of flowering plants. Sexual reproduction provides a means of mixing the genetic material of individuals so that the next generation has variability—or slight variations—in its genetic makeup. These slight differences are what allow living things to adapt to changes in their environment over time.

Plants can reproduce by asexual means, but the new individuals have no variability—they are identical to the parent plant. There are times when this is a good thing for humans. For example, if we like a particular bush and we want another just like it, we can take cuttings from the first bush and grow another. Pollination has no part in this process.

If we want seeds, however, we must have pollination. And seeds are the key to agriculture. Nuts are the seeds of trees. Corn is the seed of maize. Beans are the seeds of legumes. Sometimes the seed is forgotten because we emphasize the protective material more than the seed itself. The crunchy apple, the creamy avocado, and the sweet berries we eat are just protective material wrapped around seeds. If there was no pollination, there would be no seeds to cover, so there would be no crop to eat.

Agriculture has gotten more complicated over the years. Many of our crops are hybrids that may be sterile, and we have manipulated certain crops to produce fruit without seeds. But these are man-made creations that cannot survive without human intervention. If you think of pollination as being necessary to produce seeds—and seeds as being necessary to produce the next generation—you basically understand the system.

If we don’t eat the seeds directly, it is easy to forget how important they are. Take carrots for example. We don’t eat the seed, we eat the root. The same goes for beets and radishes and turnips. But somewhere out there people are growing these crops for their seeds so that we have something to plant the next year. The same is true for the crops grown to feed livestock. Although one farmer may be growing alfalfa to feed his dairy cows, another farmer is growing alfalfa just for the seeds. If he didn’t, what would the dairy farmer plant next year?

All this seed growing requires pollination. Some species of plants pollinate themselves. Some are pollinated by the wind, by flowing water, or by birds and bats. But most species are pollinated by insects.

People argue that you can feed the world with non-insect pollinated plants. This is probably true, as long as you eat nothing but grain: corn, rice, wheat, millet, barley, oats, etc. But would it be a healthy world? Definitely not. Our need for a varied diet of fruits and vegetables could never be met with non-insect pollinated plants.

Pollinators are not easily replaced. They have evolved along with the plants they pollinate for millions of years. Although we have no replacements ready to take their place, we insist on destroying untold billions of them every day. And we believe we are intelligent.

Rusty

I wanted to know if it was one-third [...]]]> A while back I wrote Bees pollinate one-third of what? Do we really know? In that post I questioned the frequently repeated statement that “bees pollinate one-third of the human food supply” because I could never discover who calculated this number or how it was calculated.

I wanted to know if it was one-third by weight, volume, calories, dollars, species, or some other measurement. I wanted to know if the one-third was really pollinated by bees, or if that number included all pollinating insects, or if it included animal pollinators as well.

This research is a chore I managed to put off. But this morning I received an impressive review of published literature from an interested reader. You can read her original comments, which are appended to the original post. What she found is interesting. Everyone it seems–even in the peer-reviewed literature–is citing someone else when they publish these numbers. By following the citations backwards, she pinpointed a publication by McGregor (1976) as the source for most of these comments. But no one, so far as she can tell, ever shows calculations.

The suspect publication by S.E. McGregor, “Insect Pollination of Cultivated Crop Plants,” comes closest to providing something of value. But even this document mentions percentages of the human diet without further defining what is meant or how it was calculated. He writes about the number of food species pollinated by insects and about the acres of U.S. soil planted to insect-pollinated crops. From there–in a truly mind-bending leap of faith–he draws conclusions about the percentage of our diet that is derived from insect-pollinated plants.

So it looks like we still don’t have a complete answer, but I wanted to thank Jess for all her efforts at trying to solve this vexing problem . . . and for finding McGregor.

It occurs to me that this conundrum–of one author citing another ad infinitum–is something that we as individuals and societies must be wary of. It is so easy to believe often-cited statistics, advice, or beliefs just because they are often cited. We assume that if everyone says something, it must be true. In this case I am not saying that insects don’t pollinate one-third of the food supply, I just want to know how the calculation was made. Is that asking too much?

Rusty

First of all, that estimate varies with the researcher, but it usually includes all animal-pollinated crops, not just those pollinated by bees. These animal pollinators include many types of insects as well as birds [...]]]> News reports insistently tell us that bees pollinate one-third of the world’s food supply. But what does that really mean?

First of all, that estimate varies with the researcher, but it usually includes all animal-pollinated crops, not just those pollinated by bees. These animal pollinators include many types of insects as well as birds and bats. Nevertheless, some folks estimate that bees are responsible for about 75% of all animal pollination. But again, the numbers vary.

Secondly, the “one-third” estimate usually includes that portion of the meat supply that was fed animal-pollinated crops, such as alfalfa and clover. This is another number that is hard to calculate because, in modern agriculture, more and more animals are fed grains instead of leafy forage.

The two-thirds of the food supply not pollinated by animals is dominated by the grains. Most grains are in the grass family and are normally pollinated by the wind. They include wheat, corn, millet, rice, rye, barley, oats, spelt, sorghum, and lesser known crops such as teff and triticale. Quinoa and amaranth are two non-grass grains that also require no animal pollinators. The two-thirds portion also includes crops that could be pollinated by animals, but are not, such as potatoes. (Nearly all potatoes are propagated by seed pieces, which are not seeds at all but chunks of potato that sprout when planted.) Lastly, the two-thirds includes fish, and that amount of meat which is raised on grain or other crops not pollinated by animals.

So why are animal-pollinated plants so important? The grains and meat can supply all the calories, protein, and fat we could possibly use, but the flowering plants provide the vast array of vitamins, minerals, phytochemicals, flavonoids, antioxidants, and trace elements that we need for good health. We could not survive in a world devoid of the animal-pollinated plants, so caring for pollinators is not a choice but a necessity.

Rusty

Bee on squash. Flickr photo by cygnus921