It turns out that while bees may appear to be hard working insects, they are quite lazy—or efficient, depending on how one looks at it. When collecting pollen, bees will simply travel down a nicely planted row of crops, moving from one flower to the next until done. Scientists have observed that this behavior mediates gene flow between plants and planters have used it to decide how to plant crops so that they improve their odds of growing robust and healthy produce.
Much of the study of pollen flow between plants was done on variants of the cucurbits family, which includes cucumbers, gourds, and melons. Because of the way they're planted, this has helped us understand pollen flow up and down individual rows, but little work was ever carried out when the bees could easily move between rows. A new study, published in the journal HortScience, looks at the pollen flow from bees in a watermelon field. Since watermelon vines grow in multiple directions, the path of the bees could be a bit more chaotic.
Over two years, the researchers found that the bees would move between the flowers that were closest, even if it meant crossing rows to get from one to the other, suggesting bees were looking for the shortest paths between two flowers. Whether this is lazy or efficient is up to the reader to decide.
Elsewhere in the bee world, researchers are looking at alternatives to honeybees—which are in the middle of a population crash—for pollinating purposes. One of the most critical roles that bees carry out in the wild is the distribution of pollen. As researchers from Michigan State University and the American Museum of Natural history point out, until relatively recently, berry growers relied on wild bees, as opposed to managed honeybee colonies, to handle their pollination needs.
The switch to colonized honeybees came when current pest control practices limited the wild pollinators. However, colony collapse disorder is emptying commercial bee colonies around the world, so people are starting to take another look at the "natural" alternative. New research, published* in the Annals of the Entomological Society of America, examined over 166 native bee species that were found in Michigan Highbush Blueberry fields.
Out of that 166, 112 species of bee actively foraged during the blueberry blooming season. Since many of these species are actually more active than honeybees—they visit more flowers per minute and deposit/transfer more pollen per visit—they are hypothetically more attractive as pollinators. But many of these other bee species are solitary cavity- or soil-nesting insects, so they're likely to be present in smaller numbers than colonized honeybees.
To make a field attractive to these wild bees, especially to those that live in the soil, the authors offer up a few tips for berry farmers. "Untreated bamboo or reeds are good materials because they provide natural variation in hole diameter to attract the broadest range of species," said Dr. Julianna Tuell, the lead author of the study. While the study looked specifically at blueberries, the authors indicate that similar practices would also be useful for cherries, apples, and cranberries.
HortScience 44:6-223 (2009).
Ann. Entomol. Soc. Am. 102(2): 275-287 (2009).
* Article is open access