On Tuesday 27th October 2015 our class of Conservation Science held a conference in which we presented short introductions to our hot topics in conservation. Freya Tetley’s piece focused on whether a ban of neonicotinoids would be worth the economic loss to protect our ecosystems. With the increasing wealth of information proving that pollinator numbers are decreasing, I think it is more important than ever to look into factors that could be the cause of such population collapses.
Benefit of neonicotinoids
Widespread application of neonicotinoids suggests the insecticide must have significant benefits. The application of neonicotinoids reduces insect damage to crops, increasing yields. In the United States crop yields, namely corn, have quadrupled since neonicotinoids were first applied in 1866 (fig 1). In consequence, global food prices have dropped. The chain of positive feedback proves neonicotinoids do have their economic worth, but what about their effect on ecosystems?
Cost of neonicotinoids
Although neonicotinoid application has its benefits, it comes with a high conservation cost, which I find more important to investigate. The recent European Academics Scientific Advisory Council (EASAC) report has shown that widespread prophylactic use of neonicotinoids has severe negative effects on non-target species. There has been a 50% decline in bee populations[i] attributed to neonicotinoids, and the pesticide also has detrimental effects on other pollinators such as birds[ii]. Bees and birds are vital for plant reproduction and ultimately putting fresh fruit and vegetable our plates. Arthropods are likewise affected negatively by neonicotinoids, which may disrupt nutrient cycling and reduce soil fertility[iii] (fig 2)!
Ban on neonicotinoids?
Seeing the significant negative impacts of neonicotinoids, I wonder why the chemical has not been banned entirely? A temporary restriction of neonicotinoids was already in place in January 2013[iv], but the limited scope and length of the ban resulted in no significant improvements for ecosystems. In France various pesticides have been banned since 2004 and crop yields have not suffered. Additionally, half the European Union countries were in support of the 2013 restriction, so why not commit to a complete ban? I think the government needs to acknowledge that the loss of ecosystem services associated with pollinator and arthropod declines from pesticide application, will be more financially significant than a ban of the pesticide itself. There are alternative methods to neonicotinoid use[v] such as integrated pest management, biological control and creating hybridized species more resistant to disease. We should be focusing on applying alternatives rather than the pesticide itself.
By Lisa Kopsieker
[i] Biesmejer, JC., Roberts, S., Reemer, M., Chlemuller, R., Edwards, M., Peeters, T., Schaffers, A., Potts, S., Kleukers, R., Thomas, C., Settele, J and Kunin, W. 2006. Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands. Science 313:351-354.
[ii] Boatman, N., Brickle, N., Hart, J., Milsom, T., Morris, A., Murray, AW., Murray, K and Robertson, PA. 2004. Evidence for the indirect effects of pesticides on farmland birds. International Journal of Avian Science 146:131-143.
[iii] Desneux, N., Decourtye, A and Delpuech, JM. 2007. The sublethal effects of pesticides on beneficial arthropods. Annual Review of Entomology 52:81-106.
[iv] Gibson, C. 2013. “Victory for bees’ as European Union bans neonicotinoid pesticides blamed for destroying bee population.” The Independent. Retrieved 17th October.
[v] Furlan, L and Kreutzweiser, D. 2015. Alternatives to neonicotinoid insecticides for pest control: case studies in agriculture and forestry. Environmental Science and Pollution Research 22(1):135-147.