The present paper represents a synthesis of communications collected in the “16e Colloque Biologie de l’Insecte” which gathered about 160 researchers from France and other European countries at Lyon in October 2010 (on-line reports of the symposium http://www.insavalor.fr/CBI2010). Because insects are some of the most familiar organisms of global ecosystems and because of their diversity, they are suitable models to investigate a broad spectrum of questions, in genetics and ecology as well as on populations and physiological responses to environmental changes. Molecular ecology approaches, spurred on by the recent advances in genomics, were omnipresent during this congress and revealed their relevance for the study of specifi c proximal mechanisms. As a consequence, most of presentations were focused on functional and mechanistic biology rather than conceptual approaches, following several of the recent trends outlined below.