Scientists have discovered that insect pests that attack crops have extraordinary powers to develop biopesticide resistance.
Due to biopesticide resistance, a research team from the University of Stirling has insisted that a new way to manage resistance risks is needed.
Agriculture’s response to this resistance has been to seek new pesticides in an endless race to keep up with evolving pests for more than 70 years. However, the researchers recommend that farmers should switch to biopesticides derived from natural organisms in order to embrace the new green revolution in agriculture.
Environmentally sustainable insect pest control products, such as microbial biopesticides, are increasingly replacing chemical pesticides for crop protection. In their paper, the researchers stated: “By encouraging landscape-wide crop heterogeneity and diversifying the biopesticides available to farmers, we can exploit GEIs to minimise resistance risks and preserve biopesticide efficacy.
“This approach requires agricultural stakeholders to prioritise diversity and efficiency, both within agricultural landscapes and the biocontrol marketplace.”
The biopesticide resistance research, ‘Increasing ecological heterogeneity can constrain biopesticide resistance evolution,’ is published in Trends in Ecology and Evolution.
The impact of biopesticide resistance on food security
The evolution of resistance to biopesticides – a crucial tool in developing sustainable crop protection – has enormous implications for food security worldwide as the global population grows.
In a bid to address this emerging challenge, researchers have deployed principles from fundamental evolutionary ecological science and proposed a practical framework for managing the risks of biopesticide resistance evolution.
They suggested that farmers can help manage biopesticide resistance risks by planting a wider variety of crops and using multiple biopesticides.
They stated: “To mitigate resistance risks, we advocate increasing the range of biopesticides available to farmers whilst simultaneously encouraging other aspects of landscape-wide crop heterogeneity that can generate variable selection on resistance alleles.”
Genotype-by-environment interactions (GEIs) can significantly affect pathogen resistance, so resistance allele fitness depends on many aspects of the host environment.
Resistance evolution is becoming widespread – how can we solve this?
Scientists from Stirling’s Faculty of Natural Sciences, working with colleagues at the University of Gothenburg and São Paulo State University, conducted a synthesis of existing biopesticide resistance research. They argued that resistance evolution is already occurring and is likely to become widespread as biopesticide use increases.
Most insecticide resistance management deals with chemical insecticides and transgenic crops, as it was not designed to tackle resistance to microbial biopesticides containing living pathogens.
Dr Matthew Tinsley, Senior Biological and Environmental Sciences Lecturer at the University of Stirling, stated: “People are blinkered. They think that because biopesticides are derived from natural sources, pests will be more difficult to evolve resistance. However, we still need to be worried about pest resistance to these new agents.
“The lead time to develop biopesticides is five to ten years, so if we wait to act, we will lose these new agents because pests will already have evolved.”
Dr Rosie Mangan, a post-doctoral researcher at the University of Stirling, added: “Novel resistance management approaches are needed for these crop protection products to avoid the same treadmill of invention and loss as has happened for chemical pesticides.”
She concluded: “Our perspective argues that farmers can help manage biopesticide resistance risks by planting a wider diversity of crops and using multiple biopesticides. This will reduce the spread of resistance and help keep biopesticides effective in the long term.”
