Neonicotinoid Pesticides Harm More than Just Honey Bees

It isn't just the bees that are affected by the crop pesticides called neonicotinoid insecticides, but also soil organisms, aquatic life and farmland birds, according to a new study.

Neonicotinoid pesticides are a class of pesticides that are taken up by the plant and expressed via nectar. Previous research conducted on the chemical neonicotinoids had found that it causes population decline in bumble bee colonies. Over 90 percent of these pesticides end up in soil or water, where it can stay for very long periods of time.

Bees in Europe recently won against the pesticide, after the EU decided to impose a two-year ban on the pesticide in Europe from April, 2013. A ban, that some people say, is based on little evidence.

Now, Professor Dave Goulson from University of Sussex has found that the pesticides can affect many organisms, including fish and birds.

Data for the study came from agrochemical manufacturer Bayer on the persistence of neonicotinoids in the soil.

Neonicotinoids, if used consistently, can result in accumulation of the chemical in soil at far higher levels, where it can be dangerous to soil organisms, according to the data.

"Any pesticide that can persist for many years, build up in soil, and leach into waterways is likely to have effects far beyond the pest insects it intends to target. This is particularly so when the pesticide is highly toxic to non-target organisms. For example, less than one part per billion of the neonicotinoid imidacloprid in streams is enough to kill mayflies," Goulson said in a news release.

The study also shows that certain birds that feed on grains can be affected by the use of this chemical.

"Neonicotinoids will still be widely used on cereals, so the broader environmental impacts are likely to continue. Given the longevity of these compounds, they would be in our soils for years to come even under an absolute ban, so two years is far too short to produce any benefit, even if there were any clear plan to monitor such benefits - which there is not. It is entirely unclear what this two-year moratorium is meant to achieve," Goulson added.

The study, 'An overview of the environmental risks posed by neonicotinoid insecticides', is published in the Journal of Applied Ecology.