ENDORSE: ENhancing Diversity to Overcome ReSistance Evolution

Despite its place as a global leader in agriculture, each year the Brazilian agricultural economy loses approximately $15 billion to insect crop pest outbreaks. Indeed, insects consume 10-20% of all global crops while growing or in storage. Current agricultural practices in Brazil rely heavily on widespread pesticide application, which has led to the evolution of pesticide resistance in several significant insect pests. Such practices undermine the sustainability of important crop pest control technologies, reduce associated economic returns, and exacerbate the risks to economic production and food security in Brazil. We propose a revolutionary approach to pest management that will enhance the sustainability and long-term resilience of crop production, providing the benefit of managing insect pests more predictably.

Our solution comes from evolutionary science and the particular features of host-pathogen interactions. Insecticide resistance evolution occurs when a single control agent is applied over a broad area, then consistent evolutionary pressures drive rare resistance genes to spread rapidly through the pest population. To prevent these sweeps of resistant alleles, we are investigating how multiple fungal pathogen strains can be used in a spatial matrix across agricultural landscapes, so that selection for resistance varies in different locations, preventing a uniform evolutionary response. On their own, multiple pathogen strains may not be sufficient because of cross resistance: genes making pests resistant to one fungal strain could also confer resistance to others. However, in host-pathogen systems, the optimum genotype to defend against one pathogen is often highly sensitive to the organism's environment. Simultaneous manipulation of an environmental landscape variable (the type of crop grown by farmers) will substantially decrease the consistency of selection: we predict this will prevent resistance evolution.

In order to achieve real-world effectiveness of this pest control system, an integrated team of Brazilian and UK researchers will work together to establish the long-term prospects of our new solution. The aims are to:

1. Examine whether genetic variation for insect susceptibility to multiple fungal biopesticides under heterogeneous agricultural landscapes is stable, and assess how it responds to selection in the long-term. This will allow us to anticipate and avoid selection for resistance to multiple strains, and ensure the long-term sustainability of our pesticide resistance management system.

2. Investigate the suitability of fungal biopesticides for industrial scale production and field application in Brazil, which will facilitate product development for future industrial investment. We will also provide farmers and the crop protection industry with solutions for crop protection technology deployment, including improved delivery systems, higher pest control consistency and enhanced performance under field conditions.

3. Identify the barriers to uptake of our new pest control technologies and research methods to encourage farmer behavioural change. This research will provide economic and social science data to underpin advice for policy recommendations regarding incentive schemes, publicity campaigns and marketing strategies, thereby promoting uptake of these sustainable pest management practices.

Our work has several clear beneficiaries. We summarise them below, along with explanations for how each will benefit.

Farmers and the farming economy

Our ambition to develop a sustainable system of pest management using fungal biopesticides will benefit individual farmers and the broad agricultural economy. Farmers will be able to better control insect pests, and consequently harvest higher yields, while the increased stability achieved by decreasing the likelihood of resistant herbivore outbreaks will minimize losses and insurance claims, and reduce overall volatility in the agricultural sector. If our project is successful, the benefits could extend well beyond São Paulo State and be useful for the types of agricultural systems across Brazil (and indeed elsewhere globally).


Industrial partners

A sustainable pest control technology presents advantages to the industrial partner(s) who develop products from our initial isolates. Although the work involved in developing fungal biopesticides is not trivial, companies will be much more likely to recover their investments and secure good profits if the technology is applied in a way that minimizes the chance of pest resistance evolution, and therefore secures the long-term financial rewards of investing in research and development on biopesticides. Because increasing environmental complexity may help expose the costs of hosts carrying resistance genes to other pest-control measures, our system may also incidentally help rescue some technologies that are no longer effective thanks to previous insecticide resistance; such an outcome would help not only farmers but also producers of other pest control products that have suffered rapid evolution of pest resistance (e.g. some Bt cultivars).

Policymakers

Those within national and local government agencies will also benefit from policy recommendations provided by our economic and social science advice, which will highlight the promise of these technologies at both regional and national levels, illuminate efficacy of incentive schemes, and demonstrate how these technologies can improve the agricultural economy.

The wider public

Being able to manage insect pests more predictably is likely to improve food security in both developed and developing nations. If implemented on a wide scale in the future, we expect that a more heterogeneous worldwide agricultural landscape in combination with an arsenal of appropriate biopesticides, will stabilise food prices and help minimize local food shortages that are a source of suffering, inequality and conflict. In addition, the public will benefit from reduced ecological costs of current pest control practices. For example, chemical pesticides are known to have adverse consequences for non-target organisms living on or near agricultural land. The benefits to ecosystems will pay dividends to the public, because of the many services that healthy ecosystems provide, including to agriculture, for example, in the form of plant pollination and predation of pests.