This year, experts say, the die-off has been as high as 40 to 50 percent for some beekeepers.
“We have smaller populations in the hives and higher winter losses,” said Eric Mussen, a bee specialist at the entomology department of University of California, Davis. “Bees across the country are not in as good a shape as last year. When you stress them far enough, the bees just give in.”
This year, Mussen said, many bees did not get enough nutrition because a Midwest drought reduced forage. Conversion of pasture land to corn production for ethanol also reduced the number of flowers producing nectar.
To compensate for forage loss, beekeepers fed bees more high-fructose corn syrup and other supplements. But such substitutes don't provide all the nutrients pollen does, Mussen said. Malnourished bees are more susceptible to diseases.
Lance Sundberg, a beekeeper who hauled his hives for almond pollination from Columbus, Mont., lost 40 percent of his bees this winter due to the drought and mite problems.
“You have to buy bees elsewhere to pick up your losses, and not everything we have remaining after the loss is very strong,” said Sundberg. “I had a tough time fulfilling my obligations to all the growers.”
But at least he still has bees, Sundberg said. Some colleagues were not as lucky: they lost 75 percent or even 99 percent.
Traynor, the bee broker, said he's been fielding phone calls from desperate beekeepers and growers who are short several thousand colonies — but he has no more good bees to offer them. The shortage will only get worse in the future, he said, as almond acreage grows.
Having strong hives is critical, Traynor said, especially during rainy seasons, because bees have a short period of flight time when it's dry enough to pollinate. Fewer bees may not be able to reach all the blooms in time.
In recent years, the Almond Board of California, which represents more than 6,000 growers, has poured $1.4 million into bee health research. The group also worked on alternatives to reduce growers' reliance on honeybees, said Bob Curtis, associate director of agricultural affairs.
One is the so-called “self-compatible” almond tree, which can set nuts using pollen transferred among its own flowers, thereby needing fewer bees.
The group also is urging growers to plant forage to help sustain bees before and after almond pollination. And it's exploring using blue orchard bees, which are solitary bees that do not live in hives but nest in small cavities, to augment the honeybee workforce. But building up those alternatives will take time.
“It's tenuous right now,” Curtis said. “We've got fewer bees. And if something goes wrong with the weather, some growers could be in trouble.”