Entomologists Buzzing About Vanishing Bee Populations

30 - March - 2011

Entomologists are studying the reasons behind an enormous bee die off happening across the country. They call it Colony Collapse Disorder, and if they cannot find a solution the 80% of fruits and vegetables that require pollination may not make it to market. The cause appears to be related to diseases from pesticides, but no one is certain.

Don’t be afraid of the buzz of a bee. If it wasn’t for bees, many fruits and vegetables we enjoy wouldn’t exist. They are vital for pollination of plants, but lately, they’ve been disappearing by the billions, possibly putting food supplies at risk.

“We need them for the food that we eat, for the color and variety that’s on our plate,” says Dewey Caron, Ph.D., an entomologist from University of Delaware. But this year, bees are dying by the billions, a problem threatening to wipe out crops dependent on bees for pollination. Fewer bees could cost us all at the grocery store.

Jay Evans, Ph.D., a geneticist from the U.S. Department of Agriculture, says, “What was striking is the suddenness with which the bees disappeared.” Entomologists call the mass disappearance, colony collapse disorder, or CCD. The cause is most likely toxins that make bees more susceptible to or cause disease.

“We’ve seen collapses of colonies in the past, thought they were related to stress, related to nutrition, this seemed to be very widespread,” Caron says. Bees pollinate 80 percent of fruits and vegetables by transferring pollen from one flowering plant to another. This starts fertilization that helps the plant grow seeds that turn into the food we eat.

“It’s really this pollination service that we cannot live without if we want the very inexpensive food, the abundance and the variety of foods that we’re accustomed to,” Caron says.

Bee keepers are now taking steps to control CCD so higher produce prices won’t be all the buzz.

BACKGROUND: An alarming drop in honey bee populations has beekeepers fighting for survival, and crop growers wondering whether enough bees will be available to pollinate their crops this spring and summer. Entomologists, in turn, are scrambling to find answers to what’s causing the affliction, which appears to be becoming more severe and is now appearing in Europe. As much as one-third of the food we consume comes from pollinated crops, so the shortage of bees could mean that certain foods will be in short supply.

POSSIBLE CAUSES: The affliction is known as Colony Collapse Disorder. There is not yet any clear explanation for why the bees are dying in such large numbers. It appears that their immune systems are compromised. This could be due to nutritional problems: as bees migrate from the north to the south during the winter, they feed on nutritionally poor plants and ingest second-rate sugars, such as the leftovers from soda production. Alternatively, there might be a new parasite or virus in the environment that is able to bypass the bees’ immune system. For instance, the varroa mite is a bloodsucking parasite that attacks honeybees, resulting in deformed wings and abdomens. The varroa mite also transmits viruses. The tracheal mite gets inside adult bees and clogs their breathing tubes, suffocating them. The dying of the bees might also be due to chemical pesticides commonly used in the US to treat crops.

HOW POLLINATION WORKS: Flower nectar is one of two food sources used by honeybees. The other is pollen, which the worker bees gather daily on foraging flights. As bees forage for nectar, pollen sticks to the tiny hairs covering their bodies, and some of that pollen rubs off on the next flower the bee visits. This fertilizes the flower, resulting in better fruit production. The bees unload the remaining pollen when they return to the hive, which is stored in the honeycomb, providing protein and other nutrients for the bees. The honeycomb is the central feature of the beehive, made of beeswax produced by glands in the worker bees. The comb is two-sided with cells on both side, some meant to contain food, others to serve as a nursery for the queen bee to lay her eggs.

The story is reprinted from Science Daily