Field tests show how pesticides can wreak havoc on honeybees

Mira Abed, THE LOS ANGELES TIMES
Humans are big fans of bees. We rely on them to pollinate crops like almonds, watermelons and apples.
But bees probably aren’t big fans of humans — at least, not of our agricultural practices.In particular, they ought to be offended by our fondness for a widely used class of pesticides called neonicotinoids (neonics, for short).
Studies in the lab have shown that some doses of neonics are outright lethal to many bees and that even sub-lethal doses can shorten a colony’s lifespan and harm its overall health. Results have been similar in small-scale field studies.
Still, exactly how these pesticides, which are applied to seeds before planting, would affect bees in the real world remains something of a mystery. Scientists have been locked in a fierce debate over how much — and for how long — bees encounter these pesticides in their daily lives. After all, the conditions in a field are far more complex than those in a lab.
Now, two studies published side by side in the journal Science attempt to answer this contentious question.
One of the studies was conducted in Canada. It combined large-scale field work and laboratory experiments to better understand real-world neonic exposure levels and their effects on honeybees.
The other was conducted in large fields in Hungary, Germany and the U.K. Its goal was to understand how the effects of neonics vary between countries and how exposure during the flowering season affects the long-term health of a bee colony.
Read more at: Field tests show how pesticides can wreak havoc on honeybees – LA Times