How do agricultural pesticides affect the bee microbiome?
Andres Arce, Andres Arce
Imperial College , UK; Imperial College, UK
Bees are amongst the most important wild and managed pollinator species, they are vital to maintaining healthy terrestrial ecosystems and are a major contributor to the provision of ecosystem services. For example bees are the main contributor to pollinating agricultural crops, providing a pollination service that is valued globally at over €150 billion a year. However, there is increasing concern that bees (and other insect species) are in decline. Ironically, whilst many important crops are reliant on bee pollination anthropogenic activities, such as increased agricultural intensification and the use of pesticides, are thought to contribute to causing these declines. Agricultural land currently represents the largest terrestrial biome on the planet and many intensive farming practices are reliant on the application of pesticides. Whilst exposure of non-target organisms, such as bees, to concentrations of pesticides that are acutely toxic is relatively rare, many pesticides persist in the agricultural landscapes at low-levels, resulting in repeated, chronic exposure at sub-lethal concentrations. In bees, chronic exposure to pesticide residues has been implicated in the inducement of behavioural changes, and impairment in colony development that ultimately reduce the fitness of the colony. The bumblebee core gut microbiome can act to help metabolise nutrients, as a defence against pathogens, or to break down toxins, however pesticide exposure can alters structure of the resident gut microbiota resulting in a dysbiosis, or maladaptive shift in the gut microbiome. We use data from laboratory experiments to classify the effects of five commonly used pesticides on both the microbiome and feeding behaviour of bumblebees and data from wild caught bees from agricultural landscapes throughout the UK to identify potential pesticide adapted gut bacteria that could be used to aid conservation efforts for these importa