CATCH THE BUZZ – Weighing the Costs and Benefits of Pesticide Use.

Christina M. Grozinger, Center for Pollinator Research, Department of Entomology, Penn State

There has been considerable discussion about the impact of pesticides – particularly neonicotinoids – on biodiversity in general and pollinator health specifically. While we have made significant progress in understanding these impacts, often missing from these discussions is whether the current neonicotinoid usage patterns actually benefit growers.  As we all know (but often do not discuss), it is not simply a question of either using pesticides with no restrictions or banning them completely – the best approach is to use them in a way that maximizes the benefit while minimizing the cost to growers, consumers, and the environment.

Recently, extension specialists and scientists at 12 land grant universities in the US developed a fact sheet describing why neonic seed treatments in soy are largely ineffective, particularly in northern climates. This comes on the heels of a recent meta-analysis by the US EPA which also found little benefit to the use of these seed treatments in soy. Indeed, it has been recently demonstrated that these seed treatments can actually lead to decreases in yield, by offsetting existing biocontrol mechanisms that reduce pest levels. And yet use of seed treatments in soy and other field crops has increased dramatically in recent years.

Aside from questions of cost and yield, general integrated pest management (IPM) principles tell us that using any pesticide (or antibiotic) constantly, at low levels, and across large populations will accelerate the selection and spread of resistant strains.  Many researchers worry that the current usage patterns will undermine our ability to use neonics in the long term: indeed, resistant populations have been identified in many insect species.  This is very unfortunate, because in some production systems, neonics are necessary tools.

Thoughtful and targeted use of pesticides is beneficial from both a biodiversity and an agricultural standpoint. As recently described, IPM has long been successfully merging the protection of beneficial organisms and pesticide use in a crop protection framework. It is now time to actively expand the scope to encompass “Integrated Pest and Pollinator Management” or IPPM.

Links:

Recent review of impacts of neonics on pollinators:

http://rspb.royalsocietypublishing.org/content/282/1818/20151821.abstract

Extension fact sheet on efficacy of neonic seed treatments in soy:

http://ento.psu.edu/extension/field-crops/fact-sheet-Effectiveness-of-Neonicotinoid-Seed-Treatments-in-Soybean

EPA meta-analysis on efficacy of neonic seed treatments in soy

http://www.epa.gov/pollinator-protection/benefits-neonicotinoid-seed-treatments-soybean-production

Negative impacts of neonic seed treatments on soy yield:

http://news.psu.edu/story/336981/2014/12/04/research/insecticides-foster-toxic-slugs-reduce-crop-yields

Increasing use of neonic seed treatments on field crops:

http://news.psu.edu/story/351027/2015/04/02/research/rapid-increase-neonicotinoid-insecticides-driven-seed-treatments

Neonic resistant populations of insect species:

http://www.sciencedirect.com/science/article/pii/S0048357515000826

Integrating pollinator health into IPM   http://www.sciencedirect.com/science/article/pii/S2214574515000917