The molecular impacts of chronic pesticide exposure on bee learning and memory.
Laura James, Laura Elizabeth James , Thomas G. Emyr Davies , Ka S. Lim , Ian Mellor
Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom; Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom ; Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom ; Computational and Analytical Sciences, Rothamsted Research, Harpenden, United Kingdom ; Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, United Kingdom
Insect pollinators are vital ecosystem service providers, contributing over $265 Billion dollars (USD) a year to the global economy. Estimates predict that 75% of the world’s top 100 crops are insect pollinated in some form and that 80% of this insect pollination is carried out by bees. Both managed and wild pollinators are in decline worldwide. Numerous possible causes have been cited for this decline. Including disease, parasites, habitat loss, habitat fragmentation and intensive agrochemical usage, among others. Agrochemicals, particularly insecticides, have been critiqued intensively in relation to this decline. Neonicotinoids and Pyrethroids have faced particular criticism, leading to calls for the reduction of agricultural pesticide usage. However, it is imperative that we find a beneficial solution for all parties. Our agricultural economy relies heavily on pesticides to combat crop pests and diseases, in order to maintain the crop yields essential to meet growing food demand worldwide. Nevertheless, we cannot face the consequences of the loss of pollination services. This project aims to assess the sub-lethal effects of insecticides on Bumblebee mobility, navigation, memory and learning. The project utilises a novel bee behavioural assay using a thermal-visual arena. The arena facilitates the combined use of both appetitive and aversive conditioning to rapidly train individuals to return to a cool, ‘safe’ zone in an otherwise unappealing, hot arena. Bees’ ability to learn and return to a safe zone is assessed using proprietary tracking software. These learnt behaviours will then be studied in response to field realistic levels of pesticide exposure. Further on in the project, the sub-lethal effects of pesticides on short and long term memory will be assessed by studying the direct effects on the bees’ memory pathways, which are relatively well characterised at the biochemical and molecular level.