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. |