The Guardian Newspaper reports a recent study on the use of neonicotinoid pesticides:-
“The world’s most widely used insecticides harm the ability of bumblebees to pollinate apple trees, scientists have discovered. The finding has important implications for agriculture and the natural world, say the researchers, as many food crops and wildflowers rely on bee pollination to reproduce.
There is good evidence that neonicotinoids harm bees but the new research, published in the journal Nature, is the first to show a negative impact on the vital pollination services bees provide.
The research, carried out at the University of Reading’s farm in Berkshire, exposed bumblebee colonies to different levels of neonicotinoid found in normal fields and then tested their ability to pollinate apple trees. Compared to unexposed colonies, the exposed bumblebees visited fewer trees and collected less pollen, resulting in apples with one-third less pips. The number of pips is an important sign of pollination success because it is associated with higher quality fruit, which are more valuable to farmers.”
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature16167.html