Effect of developmental stage on the nutritional value of edible insects. A case study with Blaberus craniifer and Zophobas morio

•Death’s head cockroaches and superworms are alternate food sources for humans.•Developmental stage significantly affects the nutritional value of B. craniifer.•Adult B. craniifer had the highest protein, but lowest essential amino acid levels.•Quantity and quality of the main nutrients were not affected by age in Z. morio.•Lipid indices increased with age in Z. morio but decreased in B. craniifer.