BALLSTON SPA, N.Y. — Consumers wouldn’t have nearly as much produce to choose from if not for hardworking bees that pollinate many types of fruit and vegetables.

In fact, bees make possible roughly one-third of the food Americans eat, and pollinators in general contribute $24 billion to the global economy.

But reports from around the world indicate that both wild and managed bee populations have declined significantly from factors such as disease, parasites, pesticides and loss of floral resources caused by ongoing development.

“U.S. beekeepers are losing about one-third of their bees per year, which is really an issue for agriculture,” said Samantha Alger, an environmental scientist and pollinator specialist with the Burlington, Vermont-based engineering firm VHB. “It’s a big issue with potential food security issues.”

She and Alex Burnham, of the University of Vermont’s Biology Department, recently discussed issues confronting bee populations during a Southern Adirondack Beekeepers Association meeting, with more than 60 people on hand at the Cornell Cooperative Extension office.

Information was based on their research findings from the National Honey Bee Survey.

After extensive studies at numerous sites, they found that viruses present on managed honey bees are quite often transmitted to wild bumblebees. These include the black queen cell virus, Israeli acute paralysis virus and deformed wing virus.

“So how are these viruses getting around?” Alger said. “Are they spilling over from managed bees to wild bumblebees?”

Research indicates that bumblebees are more apt to be infected near apiaries and that flowers are a platform for disease transmission.

Alger compared flowers to “dirty doorknobs” of the bee world. Just as people sometimes pick up germs and bacteria from doorknobs, honey bees can leave behind different types of viruses when working flowers, which are then transmitted to bumblebees that visit the same blossoms.

“Honey bee apiaries might be hot spots for disease transmission,” she said.

This is extremely troubling because bumblebees are considered “keystone” species in most ecosystems. They are not only for necessary native wildflower reproduction, but also for creating seeds and fruits that feed many types of wildlife from songbirds to grizzly bears, the U.S. Fish & Wildlife Service says.

Bumblebees are among the most important pollinators of crops such as blueberries, cranberries and clover and they are virtually the only insect that pollinates tomatoes. However, half of all bumble species are declining and the rusty patched bumble is now protected under the Endangered Species Act.

In her new job as a pollinator specialist, Alger advises landscape architecture firms, floral growers and state highway officials on ways to promote bee health. This includes planting more pollinator friendly flowers and a greater variety of flowers.

Also, different types of bees prefer one flower over another, so grouping flower species together instead of planting them homogenously might keep managed and wild bees separate and prevent them from infecting one another.

“Biodiversity can dampen the effect of transmission,” Burnham said.

With a PowerPoint presentation, Alger showed how large commercial migratory beekeepers travel throughout the country, taking huge numbers of bees from place to place for pollination services.

Between jobs, bees are sometimes allowed to recover in pristine habitats such as a large park. But this, too, may contribute to the spread of disease as managed bees leave behind a virus that wild bees pick up.

Southern Adirondack Beekeepers Association is one of 65 bee clubs across New York state. Alger urged all beekeepers to be more conscious of the impact their managed bees might have on wild bee populations, which are vital to the state’s $5 billion agriculture industry.

Monitoring bees for disease can reduce the chance of spillover from one population to the other.

Paul Post is a freelance writer in eastern New York. He can be reached at paulpost@nycap.rr.com.