Natural News 
April 13, 2011
A crucial lifeblood to agriculture, bees continue to face threats of extinction by things like pollution and pesticides, both of which are implicated in causing mass bee die-offs, also known as “colony collapse disorder” or CCD (http://www.naturalnews.com/honey_be… ). And scientists say that because of this massive onslaught of toxins, bees are actually entombing, or sealing off, their hive cells in an attempt to quarantine polluted pollen and prevent it from destroying the entire colony.
The Guardian writes that scientists began noticing differences among hive cells containing normal pollen, and others containing tainted pollen. The tainted cells were sunken and covered with a waxy layer of propolis, a sticky resin substance with antibacterial and anti-fungal properties. Upon analysis, the propolis-covered cells were found to contain high levels of pesticides and other toxic pollutants, indicating that the bees were purposely covering them in propolis to protect the hive.
“This is a novel finding, and very striking,” said Jeff Pettis, an entomologist at the US Department of Agriculture (USDA). “The implication is that the bees are sensing [pesticides] and actually sealing it off. They are recognizing that something is wrong with the pollen and encapsulating it. Bees would not normally seal off pollen.”
Researchers also noted that while the sealing efforts are a type of emergency reaction by bees to being bombarded with toxins, they are not really all that effective in the end. According to Pettis, most of the colonies with entombed cells ended up dying off anyway.
Though there are likely other factors contributing to CCD, pesticides play a considerably substantial role in the devastating phenomenon. In fact, a document leaked back in late 2010 revealed that a popular pesticide known as clothianidin, which was approved by the US Environmental Protection Agency (EPA) in 1993, is directly responsible for killing off bees — and the EPA has known this for a while but has done nothing about it (http://www.naturalnews.com/030921_E… ).
Sources for this story include: