This article analyses interdependencies in the agri-food system; it focuses on the relationships between agri-supply and agricultural production markets, based on a case study of the emergence and development of an insect market for the protection of crops in the tomato production sector. It mobilizes the sociology of market agencements, thus making it possible to highlight the human and non-human actors, the devices and the market work that link these two markets. From the perspective of Callon's economic sociology, we first analyse the market agencements that gave rise to the beneficial insect market; we then show that it is in part determined by the dynamics of the tomato market, where its customers are to be found. The “market work” in each of the two markets makes their articulation possible. These inter-relationships build an integrated system, from agro-processing through to the commercialisation of tomatoes.