DAVIS, CALIF. — Each year for as long as he can remember, Rick Rominger and his father before him have rented honeybees to pollinate the crops on their sunbaked farm near Davis, Calif. When the days get long they pay a beekeeper to truck hives into their fields. For a few weeks the honeybees fan out to collect pollen and nectar and in the process they turn sunflowers into sunflower seeds and bean flowers into beans.
Occasionally, the honeybees misbehave and abscond to the local town, bringing back the wrong kind of pollen for Mr. Rominger's hybrids. But for the most part the relationship between honeybee and farmer has stood the test of time.
Some bee experts say that could be about to change. The number of honeybee colonies in the United States is down by almost two-thirds over a 50-year period. Two species of bloodsucking mites are chewing their way through honeybee colonies nationwide, wreaking havoc on the way. Chinese competition is driving down the price of honey.
Because of these problems, beekeeping no longer earns much. Some operators are hanging up their veils and putting away their smokers.
This means the cost of pollination is rising and occasionally there are honeybee shortages. With 1 out of every 3 bites of food the result of pollination, bee specialists are looking for alternative ways to do the job.
Princeton University researcher Claire Kremen is a champion of native bees - the wild, distant cousins of the honeybee. Dr. Kremen says farmers have been relying too heavily on honeybees, and that other species of bee such as bumblebees, mason bees, carpenter bees, and sweat bees can do a much better job of pollination.
"I kind of think of wild bees as being our insurance policy," Kremen says, adding that there are 1,500 species in California alone.
Working on farms near Davis (including Romin-ger's), Kremen's team has found one bee species that is 10 times as good at pollinating sunflowers as the honeybee, a European import. But, she says, the numbers of native bees are kept low by typical commercial farming practices. Many farmers scrape their farms clean of weeds, in the process removing the kind of habitat the bees need to nest and forage.
Kremen wants Rominger and other farmers to plant hedgerows of native plants and take more care in their use of pesticides. She says if they do that, they could have all the pollinators they need on the farm without paying a penny to rent honeybees.
At Full Belly Farm in the Capay Valley, about 20 miles from Rominger's, there are plenty of native bees. Right now, it's harvest season in the tomato fields. The shoulder-high cherry-tomato plants are laden with red, green, and yellow fruit. Several thousand bumblebees buzz the flowers in the four-acre field.
They are not there by accident. Full Belly farmer Paul Muller says it's part of his organic farm's plan to grow insects as well as plants. During 20 years of experimentation, Mr. Muller and his partners have planted swaths of native flowers to provide pollen and nectar sources year round. They leave a lot of weeds around the edges of fields. This attracts native bees as well as other beneficial insects.
"We're just dancing in the dark here with something that we think is enhancing insect ecology," says Muller. But Kremen's research shows that Muller's experiments are working. She says Muller doesn't need to bring honeybees onto the farm to pollinate the crops.
Persuading other farmers to change will be an uphill battle, Muller says. "It's an aesthetic thing. Farmers think the ideal is to have all their rows neat and straight and not a weed in sight. But if you want insects it doesn't work that way."
It's not aesthetics that worries Rick Rominger, but reliability. "You like to think in the long term. But in our business if we trip this year, we won't be here next year."
Rominger wants to know precise details of the native bees' nesting habits before trying to create habitat for them. He's concerned about the investment. Native plants cost money at the nursery and reduce the amount of available cropland.
But there are hidden benefits to switching to native bees, Kremen says. Hedge-rows can harbor a range of beneficial insects that keep pest insects under control and reduce pesticide costs. They might also provide new hedgerow crops such as blackberries or rose hips, which can be sold for profit.
Underlying Kremen's arguments is the fear that native bees are in danger because they face pressure from development in their wild habitat. Two species of bumblebee have vanished from Oregon and California in the past five years alone. If Kremen can persuade farmers to make bee habitat on the farm, it's one way of making sure native bees are there for farmers should they come to really need them.
While owners of small, organic farms may warm to the idea of using native bees, Kremen admits it may prove difficult to convince big agriculture to make the change. But she says small farmers often lead the way because they have the flexibility to implement change. As more data come in about the effectiveness of the native bees as pollinators, she predicts more farmers will get on board.