Have you thanked a bee lately?

Roughly one out of every three or four bites we take is due to the busy little bees that pollinate our fruits and vegetables.

Without bees, our food would cost more. Some might not be readily available at all. So our health is linked to the bees' health.

Entomologists and agriculture experts have long been aware of the decline of many pollinators, including bees.

One of the hardest workers is the honey bee, a non-native species. Hives of these bees are trucked cross-country to pollinate oranges in Florida, apples in Pennsylvania, blueberries in Maine.

In 2006, when managed bees began disappearing and dying - a condition that, without a known cause, was later dubbed Colony Collapse Disorder - research efforts went into high gear.

This year, the European Union voted to ban neonicotinoids, a widely used class of pesticides, which some have targeted in honey bee declines.

But that's just part of the story.

A gut parasite also is a major health issue for honey bees. And a recent study showed that fungicides on pollen, while not killing the bees, makes them more susceptible to the parasite.

Nutrition is yet another issue.

So researchers no longer focus on Colony Collapse Disorder, said Christina Grozinger, director of Penn State's Center for Pollinator Research. "We talk about bee health in general."

We can't ban all pesticides, Grozinger said.

"We need to eat. . . . We need to find a balance," she said, "using pesticides in a thoughtful manner that reduces exposure and risk to pollinators."

Nevertheless, pesticides and other environmental contaminants will be a focus at an international pollinator conference the center is hosting this month.

A non-technical version of the latest news on bees - and their "well-beeing," as organizers note - will be offered at 7 p.m. Wednesday at West Chester University's student union, with events geared to adults and children (information: www.easternapiculture.org).

Meanwhile, researchers have developed a new appreciation for the hundreds of species of wild bees that also pollinate our plants.

One recent study of 600 farm fields in 20 countries found that wild pollinators did half the work. It also found that a plant's output increased when more kinds of bees visited.

"That puts a whole new slant on agricultural pollination," said Rachael Winfree, a Rutgers University bee expert involved in the study.

It means that just by leaving natural habitat near their fields - patches of wildflowers, say, that give wild bees a place to live - farmers can increase their yields.

All this work is fairly specialized, but citizen scientists can help, too.

For six years, dozens of bee-lovers in this region have participated in the Great Sunflower Project, organized by San Francisco State University biologist Gretchen LeBuhn.

People spent 15 minutes counting the bees that visited a plant - usually a particular sunflower - in their yards.

LeBuhn realizes that we can do so much more - such as count bees on other flowers and in other habitats.  

"I want to find out what's getting the most bees," she said.

Ultimately, the data could help gardeners and land managers select better plant species to better foster good bee health.

GreenSpace: How You Can Help Bees

Experts offer this advice:

Buy local honey to support your local bees and beekeepers.

Plant bee-friendly plants, such as aster, cosmos, beebalm, and rosemary. Penn State's Center for Pollinator Research (http://ento.psu.edu/pollinators) is a good resource, as is the Xerces Society (www.xerces.org), a pollinator conservation organization that has published a book on the subject.

When buying from a nursery, ask for plants that have not been treated with neonicotinoids. This will result in a more bee-friendly plant for you, and will put pressure on the market.

Join the Great Sunflower Project's Aug. 17 bee count (www.greatsunflower.org).EndText