Abstract
Biodiversity is changing rapidly, but these changes are best known for a few well-studied groups, such as birds and mammals. Insects in general have received much less attention, with the possible exception of honeybees or butterflies. The data available to trace variations in pollinator abundance over the recent past are therefore highly disparate, and their analysis sometimes produces inconsistent results. Recently, these variations in insect abundance have been the subject of scientific controversy, with several studies showing declining or even collapsing insect populations, while others detected no significant changes, and sometimes even increases. The lecture will present these different studies, the mechanisms responsible for the changes observed and analyze the reasons for the controversy. Standardized monitoring of insects, thanks in particular to participatory science, can help to better objectify these changes.
