There are more types of pollinators than most people probably realize. These include moths, flies, wasps, butterflies and beetles, but during the Deschutes Land Trust’s Nature Night in April, bees were the center of attention.
“Bees are the most important pollinators, period,” Mace Vaughan told the sold-out crowd at the Tower Theatre. Vaughan is the pollinator conservation program director for the Xerces Society for Invertebrate Conservation, and he enlightened the crowd about the thousands of bee species and the role they play in our global food supply. He also focused on the threats bees endure and how the common gardener can play a part in reviving bee populations.
Why are bees unique?
Bees have three qualities that make them unique. They collect and transport pollen; they forage in the area around their nest; and they exhibit a behavior called flower constancy, which “is a fancy way of saying insects can learn,” said Vaughan.
Once a bee knows where to find the nectar and pollen in a blossom, it will return to harvest more the same way.
Vaughan’s passion for these insects is infectious. “I’m really an entomologist by training, so I get to geek out on bugs,” he said.
He then rattled off characteristics of some of his favorite bee species. “The leaf cutter bees to my mind are the most intriguing bees. They (collect) pollen on the bottom of the abdomen. They’re pugnacious. If you poke at them, which I do frequently … it sticks (its abdomen) up in the air like a scorpion and walks around like Popeye like ‘Eh, don’t mess with me.’ It’s a really tough bee with a lot of attitude, and I have a lot of appreciation for that.”
Another bee Vaughan gave high marks to is the green-striped sweat bee that shimmers with a green iridescent body.
“You plant a flower in your backyard and you see this thing come and dance around on a blossom, you can’t help but be charmed,” said Vaughan.
As part of his job leading the largest pollinator conservation program in the world, Vaughan works on habitat restoration, publishing technical guides and books, including “Attracting Native Pollinators.” He also works with national organizations, including the U.S. Department of Agriculture’s Natural Resources Conservation Service, to develop wildflower meadows where pollinators can thrive. “To date since 2008 the work of the Xerces Society’s pollinator conservation program has lead to over 120,000 acres of habitat on the ground for bees,” said Vaughan.
Bee population decline
Of course there wouldn’t be a need for a conservation program if there weren’t a problem. In this case, it’s the alarming rate of decline and extinction of various bee species, the phenomenon of colony collapse disorder, or CCD, and the fact that “85 percent of plants worldwide require a pollinator in order to set seed or set fruit,” said Vaughan. And “35 percent of crop production depends upon bees. That’s worldwide.”
Vaughan explained that for the past 30 to 40 years, he’s heard that 1 in every 3 mouths of food and drink that we consume depends upon pollinators. “I didn’t buy it until someone explained to me that it’s not just apples and blueberries and melon and squash. We’re talking about beef and dairy that are feed on alfalfa, and in order to grow alfalfa hay, you need alfalfa seed, and in order to produce alfalfa seed you better have bees. … This (figure) includes oils. … To get sunflower oil you need sunflowers, and to get sunflowers you better have pollen. And so all of a sudden one in three sounded like a pretty conservative number.”
The threats responsible for the severe decline in bee populations include habitat loss, disease, pests, climate change and pesticide and insecticide use in big agricultural settings as well as in the home garden. The statistics that Vaughan provided were staggering.
He outlined the decline since the end of World War II. Lots of people kept hives during the war because of a sugar ration and a need for wax production. At the end of the war, there were 4.5 million to 5 million managed honey bee colonies in the United States. Today there are about 2.25 million. Since the 1990s, a near eradication of the feral honeybee has occurred because of a disease-spreading tick called varroa mite. From the mid-1990s to 2006 beekeepers lost, on average, 15 to 22 percent of hives. In 2006 CCD began, and the decline accelerated to yearly loses of 29 to 36 percent of hives. “If you’re a beekeeper in the state of Iowa, you lost 65 percent of your hives last year. If you’re in the province of Ontario, you lost 48 percent of your hives.”
CCD is a total collapse of a healthy hive that the science community suspects is caused by a combination of pesticide use, bee pests that spread disease and poor nutrition that makes bees more susceptible to stressors.
“You’ve got a strong honey- bee hive that all of a sudden, you go back two weeks later and all the workers are gone. The queen is left behind with a couple of young workers, and it just collapses,” said Vaughan.
This serious decline in the health and number of hives has driven up costs of renting hives. In California’s Central Valley where almonds are grown, farmers rent honeybee hives to place in their fields for pollination. Twenty years ago a hive rental was $35 to $40. Today it’s $175 to $200 per use. And for almond production there is a three-week bloom time in February when 1.6 million managed hives are needed to pollinate the blooming trees. Without the bees, almond production would be significantly lower, raising the cost and lowering availability of almonds globally.
Home garden help
Although the numbers of decline are alarming, there are ways the home gardener can help bring back pollinators, Vaughan said. Think of your yard as a bee habitat, and fill it with places they can nest and forage. Ideal foraging habitat consists of a variety of native plants that have abundant nectar and pollen. And the plant variety should be such that there’s something blooming from early spring through fall. Plant in blocks of color so there are big splashes of color to attract lots of bee activity.
“In general our native plants typically provide more food, more resources for our bees than nonnative plants. Many garden plants, such as peonies, mums and primrose, have been bred to be showy or easy to produce. As a result, their flowers — while bright and showy — offer little or no pollen and nectar for bees,” said Vaughan. “If you want a plant that really brings in the bees and other pollinators, the native mints are phenomenal and later in the spring the Deerbrush. That thing is covered in bees,” said Vaughan.
For a full list of native plants that bees love, visit the Xerces Society’s Bring Back the Pollinators page, www.xerces.org/bringbackthepollinators.
Perhaps the biggest thing to consider when creating a bee-friendly habitat is eliminating pesticides, and in particular insecticides. Even ones labeled organic, including pyrethrin, spinosad and beauveria bassianaare, are deadly to bees.
“If you’re buying plants, especially if you’re trying to buy plants for pollinators, ask your nursery to make sure that those plants were not treated with systemic insecticide,” said Vaughan. If you must treat aphids or other pests, Vaughan says insecticidal soaps, horticultural oil and neem are better options. “If you don’t spray (these) directly on a bee, it probably won’t kill them.”
The three types of native bees are solitary tunnel-nesting, solitary ground-nesting and social bumblebees, and they all seek out different types of shelter. Tunnel-nesting bees make homes out of hollow plant stems, old beetle tunnels and man-made cavities. “If you want to have them around, you need to conserve snags and brush piles,” said Vaughan. When pruning raspberry, elderberry, snowberry or rose bushes, keep the stems. And as they dry out, watch as the bees move in. Nests can also be made by grouping bamboo together or drilling holes into a block of wood with a depth of at least five inches. “There are all sorts of ways to keep these solitary tunnel-nesting bees, even on your back porch. These are really gentle, nice bees.”
Ground-nesting bees like unmowed areas, brush piles and pruned pieces of bushes. Social bumblebees nest in abandoned rodent burrows, brush piles and unmowed areas.
Lastly, Vaughan recommended talking to neighbors about the bee habitat you’re creating. In Portland, there’s been a big movement to create urban meadowscapes where front yards are filled with colorful wildflowers, clover and other blooming plants. But this aesthetic is more overgrown and native than some would prefer, so Vaughan recommends adding a “Bee Friendly” sign and creating an edge on the lawn. “Everyone loves an edge, so if you get the mower out and stick a sign (in your yard) then people know, ‘Oh, that’s on purpose.’”
Vaughan’s closing statement to the crowd reminded everyone that not only is the work of creating bee habitat important, it’s also a blast. “I hope for all of you that (this) opens your eyes to not just the bees, but the flies and the wasps and the beetles and the butterflies and the moths and eventually you’ve got more birds in your backyard. … It’s a way to have this wildlife that you can literally walk right up to and stare at and all of a sudden discover.”