Study encourages farmers to rely less on rented bees

California farmers can save money on their pollinated crops and ensure a more ecologically sustainable food supply, which could eventually reduce prices of pollen-based produce, if they rely less on renting honey bees, according to a recent study by researchers at UC Berkeley.

The study, published in the June issue of the journal Rangelands, valued wild, free-living bee species to garner between $937 million and $2.4 billion per year for California agriculture. The study said the value of the bee species could accrue an even greater estimate if farmers relied less on renting honey bees to pollinate their crops, including such produce as almonds, cherries, apples, cantaloupes and blueberries.

Claire Kremen, UC Berkeley associate professor of environmental science, policy and management and senior author of the study, said these estimated economic values are a composite of what growers currently receive for free.

The study estimated that wild bees, primarily found in California rangelands, account for 35-39 percent of all pollination services to the state’s crops. For the remaining approximately 60 percent, farmers rely on rented honey bees that usually come from Florida.

One-third of Californian agricultural revenue comes from — which represents $11.7 billion dollars a year, according to the study — comes from pollinator-dependent crops.

“Since 2006, there has been a definite increase in honey bee colony losses after winter from 15 percent to 30 percent, which is a great jump in the United States,” Kremen said.

Rebecca Chaplin-Kramer, a postdoctoral researcher in the ESPM department and another author of the study, said relying mainly on rented honey bees, which many farmers currently do, is not a very sustainable option, especially in the future.

Lynn Huntsinger, UC Berkeley professor of rangeland management, said she attributes the common renting of honey bees in the state to a farmer’s propensity for control and certainty that their crops will be fertilized rather than hoping the free, wild-living bees will pollinate at the right times and to the needed degree.

“Rented pollinators do give farmers a real certainty, but they cannot depend on just one species of bee,” Huntsinger said. “This is a false sense of security, because you need the strength that a diversified pollinating species can acquire, which can be supplied from the bee species found in nearby rangelands.”

Large monoculture farms often overwhelm the capacity of naturally occurring pollinator species to provide these services and therefore rely highly on outsourcing their pollinating services, the study states. These monoculture farms of pollinator-dependent species usually solely grow either almonds, melons, blueberries or apples, which creates a huge demand for pollinators during a short time interval.

Kremen said the way current industrialized monoculture farms operate will not be a sustainable practice because it unfavorably impacts the environment.

According to the study, the practice that adversely affects the environment is an industrialized monoculture’s often scant diversity of crops, which the pollinators, including the bee species, need.

“Pollinators will get sick if they only get one food — it’s like people will get sick too if they constantly eat Big Macs,” Kremen said.

To ensure the sustainability and diversification of pollinated crops, Huntsinger said she believes people should understand that rangelands owned mainly by ranchers work in synergy with farmers to support these free wild-living bee species.

Chaplin-Kramer said farmers and ranchers currently do not recognize how important their relationship is to each other in terms of ecosystem services.

“About 35 percent of food production depends on the world pollinators, and those foods would not exist without these pollinators,” Kremen said.