There has been much attention given to the devastating loss of honeybees because of pesticide poisoning, mites and more. Did you know that these valuable pollinators are not native to North America? The Western honeybee (Apis mellifera) was imported by European settlers who came to this country to farm in the 1600s.
Honeybees create new colonies, increasing their numbers with swarming behavior. Wild honeybees move out as a swarm from one colony to start a new one. This swarming behavior was responsible for the honeybee migrating north and west from Virginia, where they are first believed to have become established. By 1843, they reached Kansas, then moved further west when Mormons took them to Utah in 1848. Transporting hives by sea, a botanist introduced Western honeybees to California in 1853.
We have come to rely on the industrious honeybee for pollination of many crops and are concerned about the decline of wild and domesticated Western honeybees. However, we should not forget native pollinators, like dozens of species of bumblebees in the Northwest. These large, furry bees are also hard workers, helping to pollinate many fruit and vegetable crops.
Bumblebees nest primarily in underground cavities, such as abandoned mouse burrows. New nests are started by overwintering queens. Each queen starts a new colony by laying no more than six eggs. These eggs hatch into sterile female workers that care for the queen, the additional brood she begets and the nest.
Unlike larger honeybee colonies, a bumblebee colony has a maximum of a few hundred workers. At the end of the season, the queen will lay female and male eggs. These will hatch, emerge from the nest and mate. The mated females become next year's queens and find a protected place to winter. The other bumblebees, including the old queen, will die.
The buzz from bumblebees does not come from the movement of their wings. It is actually the rapid vibration of their flight muscles. They use these same vibrations to warm their bodies to fly in cool weather, allowing them to fly earlier in the season and at lower temperatures than other insects (including honeybees).
Like honeybees, bumblebees help with pollination by moving pollen from flower to flower to collect nectar and pollen for feeding the colonies. However, they are also "buzz" pollinators. The vibration of their flight muscles also vibrates the flower they are visiting. Some flowers are "self-pollinating" and do not need a transfer of pollen. However, movement from wind, or buzz pollination, is needed to shake the pollen off the anthers within the flower. Crops helped by buzz pollination include blueberries, cranberries, kiwi, eggplant, peppers and tomatoes.
Bumblebees, honeybees and other native pollinators are at risk. As gardeners, there are simple things we can do to help, such as planting a pollinator garden that includes native flowering plants. And avoid using insecticides.
-- Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.