New research: An overview of the environmental risks posed by neonicotinoid insecticides

By Dave Goulson, published in the Journal of Applied Ecology 2013


1. Neonicotinoids are now the most widely used insecticides in the world. They act systemically,

travelling through plant tissues and protecting all parts of the crop, and are widely

applied as seed dressings. As neurotoxins with high toxicity to most arthropods, they provide

effective pest control and have numerous uses in arable farming and horticulture.

2. However, the prophylactic use of broad-spectrum pesticides goes against the long-established

principles of integrated pest management (IPM), leading to environmental concerns.

3. It has recently emerged that neonicotinoids can persist and accumulate in soils. They are

water soluble and prone to leaching into waterways. Being systemic, they are found in nectar

and pollen of treated crops. Reported levels in soils, waterways, field margin plants and floral

resources overlap substantially with concentrations that are sufficient to control pests in

crops, and commonly exceed the LC50 (the concentration which kills 50% of individuals) for

beneficial organisms. Concentrations in nectar and pollen in crops are sufficient to impact

substantially on colony reproduction in bumblebees.

4. Although vertebrates are less susceptible than arthropods, consumption of small numbers

of dressed seeds offers a route to direct mortality in birds and mammals.

5. Synthesis and applications. Major knowledge gaps remain, but current use of neonicotinoids

is likely to be impacting on a broad range of non-target taxa including pollinators and

soil and aquatic invertebrates and hence threatens a range of ecosystem services.

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