The invention relates to a tray for use in large-scale industrial insect farming. More in particular, the invention relates to a live insects tray for incubating insects prepupae and pupae, the tray having a space limited by walls, for housing insect prepupae and pupae, wherein the walls are impenetrable by an insect, and that at least one of the walls is at least partly permeable for gases, such as the top wall. Furthermore, the invention relates to a rack for holding at least one tray and relates to an assembly having said rack and at least one of said trays. The invention also relates to the use of said rack with at least one tray or said assembly for incubating insect prepupae. In addition the invention relates to a method for incubating insect prepupae and/or insect pupae, preferably of black soldier fly.