How can policymakers and researchers develop effective insect resistance management guidelines? A quantitative and qualitative study of Brazilian farmers' perspectives and attitudes

Societal Impact StatementToday, over 80% of the US and Brazil row crop acreage has plants expressing insecticidal proteins to prevent the damage caused by caterpillars. These plants (crops expressing Bacillus thuringiensis, Bt, toxins) have brought several benefits to farmers, the environment, and society. However, these can be eroded when insects develop resistance to these toxins. Researchers and regulatory agencies have developed tactics that should be followed by farmers to avoid resistance but with limited efficacy. Our research provides recommendations for researchers and policymakers that are based on farmers' perspectives, thereby offering changes for current guidelines to successfully manage insect resistance and protect Bt crops' efficacy. Genetically engineered crops expressing insecticidal proteins produced by Bacillus thuringiensis (Bt) have brought numerous benefits; however, pest resistance evolution poses a threat to the sustainability of this technology. Insect resistance management (IRM) for Bt crops has been defined as a wicked problem as it involves sociobiological complexities. A main challenge in IRM is the adoption of non-Bt refuge, which is one out of the few strategies amenable to human intervention.This study investigated farmers' perspectives on information sources and IRM practices in Brazil using quantitative and qualitative data collection. A total of 145 farmers responded to online Qualtrics surveys, and 13 farmers participated in person to open-ended interviews.This study demonstrates that farmers rely on strong social networks for information exchange and that sources with expertise based on local field experience are the most reliable channels of communication. We identified new challenges for refuge adoption such as the need to spray insecticides for pests not targeted by Bt and the intangible aspect of resistance evolution. Based on results of sources of information and perspectives on IRM practices, we discuss strategies that may be successful in delaying insecticide resistance evolution based on local contexts.This is the first study to investigate Brazilian farmers' perceptions on information sources and IRM strategies using qualitative data. Our results provide important elements to orient research development and decision-making in biotechnology policies for the agricultural sector in Brazil and other similar contexts.