| − | Because of their vital role as pollinators, bees are responsible for 15 to 30 percent of the food U.S. consumers eat. However, in recent years there has been a steep decline in the population of bees, and some scientists claim that unless this is arrested the supply of some fruits and vegetables may also decline. <ref> http://news.nationalgeographic.com/news/2004/10/1005_041005_honeybees.html </ref> | + | Because of their vital role as pollinators, bees are responsible for 75 to 80 percent of the food U.S. consumers eat. However, in recent years there has been a steep decline in the population of bees, and some scientists claim that unless this is arrested the supply of some fruits and vegetables may also decline. <ref> http://news.nationalgeographic.com/news/2004/10/1005_041005_honeybees.html </ref> |
| − | This decline is considered to be the result of diseases such as the varroa mite and other parasites, and the widespread practice of spraying crops with pesticides. Some scientists have asserted that the increased use of genetically modified crops may have a role to play, but the evidence for that is not yet clear. | + | This decline is considered to be the result of diseases such as the varroa mite and other parasites, and the widespread practice of spraying crops with pesticides. Some scientists have asserted that the increased use of genetically modified crops may have a role to play, but the evidence for that is not yet clear. |