Dirt. The bees just fed a variety of pollen may be less able to sterilize the food in the hive.
Alban Maisonnasse
The bees worldwide contribute about work worth $ 215 billion to agriculture, with industrial farmers often bringing swarms of bees to pollinate several hectares of a single culture. But is pollinating monocultures threaten the health of insects? A study published today suggests that forcing the bees to feed on only one type of pollen can reduce their ability to synthesize an enzyme needed to protect beehives of infection. "This is a very good first step," says behavioral ecologist Marla Spivak of the University of Minnesota, Twin Cities. "In the past, there have been studies on the protein content of acids and amino acids pollen, but no link between that to the immune systems of bees. "
bee populations in many countries, including the United States, seem to have declined markedly in recent years. many commercial beekeepers were devastated by a mysterious syndrome called colony collapse disorder (CCD), in which many worker bees disappear. Some research has suggested that the immune system of bees have been removed or are less able to defend hive against parasites. Entomologist Cédric Alaux of the french National Institute for agricultural research in Avignon wondered if the diet of bees could be changing their immune system.
"We know that in humans, the protein is very important for the immune system, and the beekeepers were told that protein nutrition was very important for bees, but no one had really tested" said Alaux.
Thus the team divided newborn bees Alaux local colonies into 80 groups and high in cages. Each group received a pollen preparations with a different protein content; some preparations include pollen from one flower type, while others were a mixture of pollen of various flowers. After 5 days, the team measured four chemical indicators of the health of the immune system of bees. To the surprise of Alaux, bees fed with the highest pollen protein showed no signs of a higher immunity. But when the team compared bees fed a varied diet with those fed only one type of pollen, they found something more interesting.
The bees fed pollen from a variety of plants showed levels higher by about 40% of a hormone called glucose oxidase, Alaux and colleagues report online on January 20 in the Royal Society Journal Biology Letters . Worker bees use this hormone for sterilizing food fed to the larvae, protecting the next generation and contribute to the collective immunity of the hive.
Next, the team plans to see if Alaux colonies resist infection in the field with various plants. They also want to know if the chemicals in particular pollen types can be linked to specific immune functions so that beekeepers can optimize the bee diet.
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