Bumble bees and other pollinators often visit the vast fields of cotton flowers in north Florida’s agricultural lands. Although cotton is mainly self-pollinating, pollination by bees can increase seed-set per cotton boll. Note the pollen grains stuck on each bee. Photo by Judy Biss

Bumble bees and other pollinators often visit the vast fields of cotton flowers in north Florida’s agricultural lands. Although cotton is mainly self-pollinating, pollination by bees can increase seed-set per cotton boll. Note the pollen grains stuck on each bee. Photo by Judy Biss

Bumble bees are among the most recognizable of insects. They are large, colorful, and a wonder to watch.  They’re also popularized in media, cartoons, and clip-art images, but beyond the popular images, bumble bees are worthy of our attention as important pollinators of both native plants and agricultural crops.  They are one of hundreds of pollinating bees that are critical to the abundance of our native lands, wildlife, and also our food supply.  Protection of pollinators has received national recognition and many programs are now geared towards pollinator conservation. 

Why is Pollinator Protection Important?

According to the UF/IFAS publication Minimizing Honey Bee Exposure to Pesticides:

The western honey bee is conceivably the most important pollinator in Florida and American agricultural landscapes. The honey bee is credited with approximately 85% of the pollinating activity necessary to supply about one-quarter to one-third of the nation’s food supply. Over 50 major crops in the United States and at least 13 in Florida either depend on honey bees for pollination or produce more abundantly when honey bees are plentiful.

And:

“Growers also use other managed bees species, such as the bumble bee to provide field and greenhouse crop pollination services. Additionally, there are more than 315 species of wild/unmanaged bees in Florida that play a role in the pollination of agricultural crops and natural and managed landscapes. These include mining bees, mason bees, sweat bees, leafcutter bees, feral honey bees, and carpenter bees, among others.”

Pollinator Protection was formally recognized at the federal level in 2014, when the President of the United States signed an official memorandum entitled: Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators  which outlines specific steps to increase and improve pollinator habitat. These steps are geared towards protecting and restoring populations of not only honey bees, but native bees, birds, bats, and butterflies; all of which are vital to our nation’s economy, food production, and environmental health.

Bumble Bee Biology and Ecology

There is much to learn about these fascinating insects.  Here are some facts to feed your curiosity.  Additional resources are listed at the end of this article.

  • Bumble bees belong to the genus Bombus within the family Apidae. As such, they are related to honey bees, carpenter bees, cuckoo bees, digger bees, stingless bees, and orchid bees.
  • There are about 50 species of North American bumble bees.
  • Bumble bees are social and form colonies like honey bees do, but bumble bee colonies are smaller (50 – 500 individuals), and their colonies only last one season.
  • Bumble bees generally make their nests in the ground, using abandoned rodent cavities or under old tree roots, etc.
  • Each spring, a mated queen emerges from winter hibernation and finds a suitable underground cavity. She begins collecting nectar and pollen and laying eggs to build her colony.
  • By late summer and into fall, the only surviving member of the colony are new queens.
  • These queens mate and then they hibernate during winter 2-5 inches deep in the soil. The following spring these queens emerge and start new colonies, repeating the annual cycle.
  • Bumble bees are adapted to a wide range of environmental conditions and can forage in cooler, cloudier, and wetter weather better than other bees. Because of this adaptation, they are generally the first bees out in early spring and the last bees out in the fall.
  • Since bumble bees are adapted to a wide range of environmental conditions, they are also able to feed on a wide variety of flowering plants.
  • Bumble bees do make honey, but only enough to feed the colony during bad weather, when they are unable to go out and forage.
  • Bumble bees, like the blueberry bee collect pollen from certain flowers using a unique behavior called “buzz pollination,” or “sonication.” This behavior is not found in European honey bees. Some plants, blueberries for example, hold tightly to their tiny pollen.  Bumble bees and blueberry bees grab the flower structure and powerfully vibrate their wings while holding onto the flower.  Their whole body vibrates and literally shakes the pollen lose from the flower.
  • Bumble bees are so effective at pollinating important food crops, they are raised commercially and sold to pollinate produce such as tomatoes, peppers, cranberries, and strawberries.
Bumble bees busy at work on our native flowers. Photo by Travis MacClendon. Calhoun County Florida Wasps and Flies

Bumble bees busy at work on our native flowers. Photo by Travis MacClendon. Calhoun County Florida Wasps and Flies

Create Your Own Pollinator Pasture

You can help increase the abundance and health of bumble bees, other native pollinators, and honey bees by creating nectar and pollen rich bee pastures.  These pastures can be filled with annual plants, which grow from seed each year, perennial plants, which return and spread on their own each year, various flowering shrubs and trees, or any mixture of above. You can also manage existing natural areas and woodlands by employing recommended prescribed fire regimes, non-native invasive plant control, and other practices to encourage a diversity of native pollinator plants.

The ideal bee pasture is one in which flowers are blooming as continuously as possible throughout the year. Research shows bees thrive best in open sunny pastures that are as large as possible, with a diversity of plants types. While flowering shrubs along woodland edges are well used by bees, a bee pasture that is allowed to become dominated by trees and shade will become less attractive to bees. A dedicated, open, sunny pasture having nectar and pollen plant diversity is best.  Just as with any field you intend to plant, the first step is to collect a soil sample for analysis of existing nutrients and pH levels. (For more information on soil samples read the article Soil Test First!

Pollinator Plant Types

There are many plants that provide nutritious nectar and pollen for North Florida’s pollinators. Some examples of plants which are good pollinator food sources are maple trees, redbuds, poplars, gallberries, blackberries, palmettos, partridge pea, mint, thistles, goldenrod, asters, tickseeds, sunflowers, squash, melons, and clovers. If you purchase a bee pasture blend from a seed company, make sure it is suited for growing in North Florida and does not contain noxious, invasive, weedy plant species. The Florida Exotic Pest Plant Council maintains a listing of documented invasive plants here: List of Invasive Plant Species.

Summary and Resources

The business, biology, and botany of pollination is fascinating and critical to sustainable and diverse food production in Florida and the United States. Bumble bees are just one of the many native pollinators that frequent our forests, fields, and gardens.  Consider turning your fallow lands or backyards into productive bee pasture and reap a sweet harvest.

For more information please see the resources used for this article below:

 

Judy Biss