Great honey bee die-off finally explained?

It has been a worrying observation from scientists and bee-keepers for some time; honey bees are dying off at an unprecedented rate, and no one knew exactly why. Now a study published in the ACS journal Environmental Science and Technology believes it has found the answer.

The answer may lie in a type of insecticide used to coat corn seeds. The chemicals in question came into use in the 1990’s, which correlates with the sharp decline in bee numbers. The poison works by paralyzing the nerves and works on most forms of insect. They have been widely used since their inception because of their ability to specifically target only insects; other animals are not affected.

The link was noticed when a bee die-off was seen during the corn planting season of March to May. During this time the seeds to be planted are coated and sprayed by a seeding machine. Any bee coming in to contact with the spray is killed in a similar way to other insects.

Unfortunately the researchers have not been able to suggest a solution to the problem. In their tests they found changing the deflector of the machine to point downwards still caused the death of 200 bees in one field. They do suggest that a method to prevent seed fragmentation could be the path forward, but further research is necessary.

The apiculture and scientific community are still somewhat divided on the issue however, with some suggesting an insect disease could also be playing a part. Research into the problem has not been all encompassing, and relatively little attention has been given to the artificial selective breeding of bees for industrial use, the displacement of and stressors on wild bees, and the effect of artificial genetic homogeneity.

The problem is confounded by several other factors. Contaminated pollen may be kept stored in a hive for months before consumption, making it difficult to know exactly where the source of the contamination came from, especially given both the vast distances the bees can cover in themselves and in professional beekeeping operations, where they can be taken across a whole country.

It is likely that pesticides are playing a considerable role in the die-off, but other factors are also likely to be involved. Another study has found that bees are more susceptible to fungal infection after being given non-lethal doses of pesticides.

Ending the use of these chemicals is unlikely, as it is so widespread as to be endemic to the corn farming system. Whether alternatives can be found is yet to be seen.