Number of bumblebees, other pollinators are dwindling

Question: Each year it seems there are fewer honeybees in my garden, however, it seems like I am seeing more bumblebees. Are my observations correct? Regardless, how do bumblebees differ from the honeybee?

Response: With the colony collapse disorder affecting the honeybee, the ratio of the honeybee to bumblebee could easily be changing. However, where data exist, trends of the broad spectrum of the pollinator group, including the bumblebee, are demonstrably downward.

Unlike social honeybees, imported from Europe in the 1600s, the bumblebee is indigenous and approximately 50 species are known in North America. The bumblebee is one of nature's most industrious and generally harmless workers. Unlike the honeybee, which dashes about everywhere, the bumblebee is gentle and slow. Round and furry, it trundles around the garden collecting pollen and nectar.

There are three kinds of bumblebee, the large queen, the smaller imperfectly formed female worker bee and the tiny male or drone bee. All are seen at different times of the year. Only the queen and the worker bees have a sting. Drones (smaller male bees that hatch in midsummer) have no sting.

Important facts to know about bumblebees include:

* Because they live in small nests, bumblebees never swarm, so you can encourage nesting in your garden without fear of this happening. The bumblebee generally considers a suitable place for nesting to be on the ground, beneath a flat object. An old mouse hole or similar hole in the ground is preferred, especially if it is underneath an old tarp, flat stone or man-made object such as a deck.

* Bumblebees do not produce enough honey for commercial use, just a few grams at a time to feed their young.

* A bumblebee's biggest enemy, by far, is a person armed with a pesticide spray. Like every other form of wildlife, it is under serious threat from the widespread application of chemicals to the land.

* A bumblebee is much less aggressive than honeybees. Generally, it will not attack a human unless its life is threatened. Typically, if you stand quietly and do not wave your arms in its presence, once it smells you are not a flower with pollen, it will move gently away.

* Often you will see a sudden increase in bee numbers midsummer when the drones hatch. As you observe this, remember a) the bumblebee is generally very passive in disposition and b) drones cannot sting.

* A bumblebee does not lose its sting and die if it uses it, as a honeybee will.

* Scientists estimate that in the United States alone, native bees perform up to $3 billion worth of pollination services annually.

While bumblebees and honeybees are the 800-pound gorillas of the pollinator world, pollinators comprise a diversity of wild creatures, from birds and bats to butterflies, moths, beetles, etc.

Bees and pollinators are essential to human survival. Without them, we would lose most of our plants and everything else. To produce seeds and reproduce, three-quarters of the world's flowering plant species rely on animal pollinators. The others use the less precise methods of wind or water to transfer pollen. Further, animal pollinator- dependent plants comprise more than two-thirds of the world's crop species, whose fruits and seeds provide more than 30 percent of the foods and beverages we consume. Various scientific groups hold the opinion that on an ecosystem level, "losing a pollinator can have a domino effect on countless other species."

Indisputable evidence is showing declines in almost all pollinator groups. A recent National Academy of Science report notes tailspin declines in butterflies, hummingbirds, bats and bumblebees and honeybees in particular. The jury is still out as to the cause of the respective declines, however scientists speculate the most likely culprit for the reduction in the bumblebee population is an exotic disease introduced by commercially reared bumblebees. Beyond disease, suspected blame for pollinator declines runs the gamut: habitat loss and fragmentation, introduced species, pesticides and global warming.

* Washington State University Extension Master Gardener Program is an organization of trained volunteers dedicated to horticulture and community service. Questions about gardening, landscaping or the program may be directed toward the Master Gardener Clinic by calling 509-574-1600 or visiting the WSU Extension office at 104 N. First St. in Yakima. New volunteers are welcome.