Combating the superpests: the battle to save our food
Aphids have adapted to several classes of insecticides. Novel molecular diagnostics can be used to detect mechanisms of resistance. (credit: Rothamsted Research).
Despite many years of research on alternative methods to control pests and diseases in crops, pesticides retain a vital role in securing global food production and this will remain the case for the foreseeable future if we wish to feed an ever growing population.
Most classes of pesticides that are currently available have their efficacy threatened by the evolution of resistance to these chemicals in their target pests. Scientists at Rothamsted Research are leading work to understand the development and causes of this differential sensitivity to pesticides. Research into the causes of resistance therefore supports strategies for optimal and sustainable use of pesticides.
How does it work?
The evolution of resistance to pesticides threatens crop protection worldwide. Pioneering work at Rothamsted, and elsewhere, has revealed the primary mechanisms of resistance, arising from modifications of proteins targeted by pesticides, or detoxification or export of pesticides before they reach their target site. Examples include work on resistance to pyrethroids and neonicotinoids, the two biggest selling classes of insecticides, and azoles, the most important group of fungicides.
For pyrethroids the scientists have identified key amino acid substitutions in the insecticide target, the voltage-gated sodium channel, and for neonicotinoids elucidated the molecular basis of metabolic and target-site resistance. With azoles, the emergence of combinations of changes in the protein target has reduced their effectiveness. Current work, with the globally significant aphid pest Myzus persicae and wheat pathogen Mycosphaerella graminicolauses genomics to identify genes involved in detoxification of insecticides, or insensitivity to fungicides, an approach that has resulted in high impact findings.
These short videos introduce some of the work presented by this exhibit.