Insects are the most numerous and specious animals on earth, and played a key role in structuring most past and Present ecological niches, including the higly anthropized agricultural ones. Here I outline some of the results of a Marie Curie project aimed at investigating how insects and other ecdysozoans evolved during earth history, adapted to key paleo-ecological events and to agricultural niches, and evolved in relation to plants. The most interesting result is about the colonisation of land by arthropods (Rota Stabelli et al. 2013 Current Biology) which happen, according to molecules, toward the end of the Cambrian, much before fossils suggests and in a period that has been always considered incompatible with life, but that recent findigs make plausible