By Zafrir Rinat | Jul. 18, 2013

Amid the plethora of environmental crises the world is facing, the disappearance of bee colonies has been pushed to the margins when it comes to public awareness. But in the long run, it is hard to ignore a problem that poses a threat to food production and will also cause serious harm to ecosystems. This is because of the major role bees play in the pollination of plants.

In laboratories around the world, scientists are trying to understand what is causing the substantial decline in wild bee populations, as well as in bee colonies maintained for honey production. Israeli scientists are front and center in this effort.

The decline in bee populations has a major impact on agriculture, since bees are generally held to be responsible for 75 percent of crop pollination around the world. Fully 90 percent of this bee pollination is performed by honeybees, which feed on the nectar and pollen from flowers. As they move from flower to flower, they deposit the pollen they pick up from other flowers, which is necessary for the germination of seeds and the development of fruit.

The annual economic cost of the decline in bee populations is estimated at tens of billions of dollars a year in the United States alone. Six years ago, American farmers lost close to a third of their bee colonies.

One of the major causes of the bees’ disappearance is disease, caused in part by viruses that hit their hives. But in recent years, significant advances have been made in preventing these diseases, thanks to methods developed in part by Prof. Ilan Sela of the Hebrew University of Jerusalem and researchers from the B. Triwaks Bee Research Center at the university’s agriculture school in Rehovot.

The bee pollination provided by 60,000 beehives is essential for Israeli agriculture. “There are crops such as avocados that are totally dependent upon pollination by bees,” said Prof. Sharoni Shafir, who heads the bee research center.

Sela recently received recognition for his research, which helped develop a treatment for bees infected with the virus. Researchers in the United States have presented proof of the connection between the virus and the damage sustained by bee colonies.

Based on Sela’s research, the Beeologics company was established in Israel to develop a treatment for the virus. The firm, which now has global operations, has developed a product that is fed to the bees and contains ingredients that “turn off” the genes in the virus.

Combating parasites

Two other researchers at the university’s bee research center, Yael Garbian and Eyal Maori, headed research efforts that led to a method to combat the harm caused by acarids, the order that includes mites and ticks. Acarids are bee parasites, and they transmit the virus that Sela researched.

Garbian and Maori addressed this problem by injecting a substance into the bees’ food that was transmitted to the acarids and then back to the bees, and that inhibits the acarids’ ability to propagate. They were able to demonstrate a decline of nearly 60 percent in the number of acarids, so commercial application of the method might substantially curb the damage to bee populations.

Researchers think another cause of the bees’ disappearance is a group of insecticides called neonicotinoids. The insecticides are meant to kill insects that damage crops, but some scientists believe they also affect bees.

The controversy over the effects of neonicotinoids, which are produced by giant chemical companies such as Bayer and Syngenta, has been ongoing for several years. The companies say there is no proof that the insecticide is killing off bee populations, arguing that the bees’ decline stems from disease and from damage to their habitats. Some scientists support the companies’ position, noting that the decline in bee populations began before the insecticides came into use.

Two months ago, the Journal of Applied Ecology published a wide-ranging survey of the environmental effects of neonicotinoids written by a researcher from the University of Stirling in Scotland, David Goulson. He concluded that there is little definitive evidence that the insecticides are killing off bees, but said there is convincing evidence that the chemicals are affecting the bees’ ability to hunt for food. He also cited research showing that bumblebee colonies did not develop in areas where the insecticides were in use.

Prof. Shafir of Hebrew University’s bee center suggests that the bees’ immune system may have been compromised by exposure to parasites, thus making them more vulnerable to insecticides.

The European Union deliberated for some time over whether to limit insecticide use in an effort to curb further harm to bee populations. It ultimately decided to limit three types of insecticides for a two-year trial period. Insecticide manufacturers were disappointed with the decision, but environmental groups say the step is justified for the sake of caution, even if there is no conclusive proof that the chemicals are the culprit.

The EU’s decision received support from the Israel Honey Council, which represents 550 honey growers. The group called on the Agriculture Ministry to enact the same restriction here.