It seems that the decline of agricultural pesticides is now well established and irreversible. Knowledge demonstrating their harmful effects on the environment or health is increasingly robust, public policies are increasingly strict in regulating their registration and use, and the flourishing market for “pesticide-free” organic food seems to leave no doubt about consumers' preference. Yet the global market for pesticides is growing steadily, even in industrialised countries. And the forecasts are rather encouraging for the pesticides industry, which is constantly proclaiming the interest of these technologies to face major challenges such as global food security, population growth or climate change. These elements contribute to making pesticides a set of technologies torn between a predicted decline and a promising future. Of course, pesticides are not the only technologies in this situation, and it is probably one of the contributions of transition studies to have shown that changes rarely occur suddenly. Literature on technology life cycles is consistent with this statement. It shows that decline is a long-term process, and that technologies destined to decline can coexist for some time with those destined to replace them. It is precisely this relationship between incumbent and alternative technologies, between declining and emerging technologies, that this chapter will examine. Using the case of agricultural pesticides, it proposes to show how the framing of alternative technologies and the way in which they are promoted contribute to reinforcing this tension between the logic of declining and maintaining certain technologies. More specifically, it focuses on the dynamics that have supported the development of bio-pesticides as credible technological alternatives to synthetic pesticides. It is based on two case studies in Argentina and Brazil. These two Latin American giants are distinguished first of all by their unwavering support for the agribusiness sector,