IPBES, which some experts classify as an “IPCC-like mechanism for biodiversity” (Larigauderie and Mooney, 2010), is a recent institution in search of recognition. One of the keys of that recognition is to be based on IPCC procedures to ensure the credibility1 of the assessments it wishes to produce. In addition to the credibility guaranteed by the reviewing procedures inherited from the climate research community, such recognition presupposes the nomination of experts that is both fair – in terms of the geographical distribution of the experts – and transparent, so as to guarantee that the results obtained are as legitimate as possible (Mitchell et al., 2006). When IPBES prioritized the main lines of its work program in December 2013, it opted to assess pollination. The pollination topic offered the advantage of having already been studied in connection with several projects coordinated by the Food and Agriculture Organization of the United Nations (FAO). An appraisal was therefore already available, and some expert networks had been identified beforehand. In addition, the subject had already been touched upon within the Convention on Biological Diversity (CBD), and its coverage in a science-policy interface should make it possible to arbitrate on existing scientific controversies. From that standpoint, IPBES became the ideal arena for coordinating an assessment of the stakes involved in several regime complexes (food security, agriculture, biodiversity, trade, etc.). The long-standing sociotechnical controversy (Bonneuil, Joly & Marris, 2008) regarding the use of neonicotinoids and their effect of causing excess mortality of bees could have been clearly expressed within the recent platform. However, we will show that the institutionalization of controversy though IPBES procedures and the IPBES expert selection process tend to attenuate the controversy on pesticides. Indeed, in 2014, a controversy was unleashed when the names of the 62 experts selected to produce th