Are neonicotinoid insecticides impacting on non-target insects and birds?

Prof. Dave Goulson, Prof Liz Hill, Prof J Wilson (RSPB), Dr David Gibbons (RSPB)

Despite considerable spend on agri-environment schemes intended to boost biodiversity, many farmland taxa, including birds, butterflies, moths, carabid beetles and bees continue to decline. This PhD will investigate the hypothesis that these declines are in part due to a particular class of insecticides known as neonicotinoids. These insecticides are toxic to insects at minute doses, and are widely used globally; in the UK they are most commonly used as a seed dressing on oilseed rape, cereals and beets. Neonicotinoids are systemic, and so are absorbed by the growing seedling to provide protection against herbivorous insects. Low concentrations are found in the nectar and pollen of treated crops, and there has been much recent interest on their impacts on pollinators. There are few data on the impacts of neonicotinoids on other non-target insects, but circumstantial evidence suggests that impacts may be widespread. In particular, it has become apparent that they can accumulate in soils. They also leach into waterways, and contaminate field margin and hedgerow plants, so they could impact on a broad range of non-target organisms, including soil-dwelling, aquatic and herbivorous insects, and their predators such as birds.

To evaluate this, we will address some major knowledge gaps:

1. Establish the levels of neonicotinoids in field margin/ hedgerow vegetation. 
2. The student will conduct bioassays to determine whether concentrations of neonicotinoids found in (1) are adequate to induce mortality in insect herbivores. This will focus in part on insect groups known to be important in the diet of declining farmland birds; grasshoppers, leaf-beetles, weevils, Lepidoptera and tipulids. 
3. The student will develop behavioural assays for Lepidoptera to quantify sublethal impacts upon both larvae and adults, including assaying the ability of adults to learn associations with food rewards. 
4. Direct evidence of sub-lethal neonicotinoid impacts on birds is absent, but one declining species – the Linnet – depends heavily on dandelion and rape seed as a nestling food source. The student will compare historic (mid-1990s) and new data on nest success levels, and examine whether nesting survival and condition is correlated with prevalence of neonicotinoids in the nestling diet. 
5. We will use data from the UK Breeding Birds Survey to determine the temporal and spatial associations between neonicotinoid usage, and the regional population trends of those farmland birds likely to be sensitive to them.  

Funding Notes:
Fully funded CASE studentship from NERC. Formal applications should be made for PhD in Biology, Sept 13 entry, using our online application system at the Apply button below. Please mention Prof.D Goulson as suggested supervisor in the application. Include full CV, transcripts, statement of interest and references.

Send project enquiries to Prof. Dave Goulson (dave.goulson@stir.ac.uk)
Application enquiries should be sent to Dr Deeptima Massey (d.massey@sussex.ac.uk)

References:
Jeschke P, Nauen R, Schindler M, Elbert A. 2011. Overview of the Status and Global Strategy for Neonicotinoids. Journal of Agricultural and Food Chemistry 59: 2897-2908. 

Krupke CH et al. 2012. Multiple Routes of Pesticide Exposure for Honey Bees Living Near Agricultural Fields. PLoS ONE 7: e29268 

Whitehorn P. et al. 2012. Neonicotinoid pesticide reduces bumblebee colony growth and queen production. Science 336: 351-352.