It sounds like a paradox: Beekeepers, environmentalists and scientists have said bee populations are plummeting to levels that threaten the supply of fruits and vegetables, since they will no longer enough bees to pollinate the foods. At the same time, however, bee populations have risen worldwide over the last few years - and by roughly 7percent.

The jump is due to an increase in the number of beekeepers, according to Peter Rosenkranz at the University of Hohenheim in Stuttgart. "Some 95 percent of bee populations are in beekeepers' hands," the biologist told DW. Bee owners can, therefore, verify just how many are buzzing about their fields and meadows.

In recent years beekeepers have had to swallow big losses: pesticides containing neonicotinoids are suspected of weakening bees and making them susceptible to mites, which latch on and deliver the deadly varroatosis disease. In winter up to 30 percent of a population can die out and need replacing in spring.

While a European Union pesticide ban is meant to counteract such losses, a larger problem remains with wild bee stocks. Roughly 500 species can be found in Germany. But in areas where industrial-scale agriculture is practice, with an attendant quantity of pesticides being sprayed, wild bees have largely disappeared.

German beekeepers collectively protested the use of bee-harming pesticides in October 2013

Bees to go

There's a reason why the expression "busy as a bee" is still in use. Bees work hard. They spend most of their days collecting pollen and dusting other flowers with it. Beekeepers get pollen and honey, farmers, rich yields on crops. Rosenkranz called it's a win-win situation, adding, however, that there's "plenty of room to increase yields" without applying additional pesticides or fertilizers - "without damaging the environment." In other words, more bees would lead to better harvests.

That's exactly the goal scientists have been pursuing, most recently in a just-published study at PLOS ONE, where scientists called for bees to kick-start biofuel production through greater pollination of rapeseed, sunflowers or corn plants. Rosenkranz said the researchers' proposal was a sensible one. Rapeseed fields, for example, could yield 30 to 40 percent more than they do now so long as "bee populations are positioned according to a set plan," he said. In other words, farmers need to order - and pay for - as many bee populations as necessary to pollinate their crops then let the insects do the rest. Pollination as a service, he added, is just beginning in Europe while other countries, like the United States or China, the practice is widespread.

The question is: Which plants to pollinate. Rapeseed or sunflower seeds can produce good honey. But farmers are increasingly planting corn for biofuel production. Corn, Rosenkranz said "is not a plant that bees are particularly fond of." Beekeepers don't make money from corn, either, which is why they're appealing for biofuel crops to be chosen based on "providing a food source for pollinating insects" - which also, of course, helps beekeepers.

Rapeseed is just one source of biofuels that can power cars and even commercial airliners

Good for bees - and your car

There are alternatives. Theoretically, a field of colorful wildflowers can also fuel automobiles. Yields would be lower - estimates range from drops of 30 percent to 40 percent lower - but bees would benefit from healthy fields rather than monocultures. Farmers, however, would view things differently, Rosenkranz said. Persuading them to relinquish 5 percent to 10 percent of profits to support ecologically rich meadows would prove challenging.

Scientists at the "Agricultural Technology Center Augustenberg" (LTZ) in Karlsruhe are currently testing varied mixtures of flowers. The right bouquet, they hope, will be friendly to bees, enrich the environment and also provide energy and high yields.