The latest on honeybees

Honeybees are responsible for pollinating the plants that make up a third of our food supply. They've been disappearing from hives in the U.S. for the last couple of years; similar die-offs are now being reported worldwide.

NewScientist reports on the latest research which suggests that the losses aren't due to any single factor. Bees on every continent except Australia are now infected with the varroa mite which originated in Siberia, and this parasite likely makes them more susceptible to other factors like agricultural chemicals.

Increasing use of herbicides has resulted in fewer weeds in some areas, and one man's weed is some bee's dinner. A variety of types of pollen provides bees with a well-balanced diet, so being limited to collecting pollen from fewer plant species may cause them to miss out on critical nutrients.

Finally, there's concern that in our effort to breed docile bees that produce a lot of honey we've lost other traits that contributed to their robustness.