Postembryonic development of the two-spotted field cricket (Gryllus bimaculatus): a staging system

The two-spotted field cricket Gryllus bimaculatus has emerged as a central model for studies on insect development, regeneration, and physiology. G. bimaculatus has the most sophisticated functional genetic toolkit of any hemimetabolous insect, making it a foremost model to understand the evolutionary developmental biology and comparative physiology of insects. However, the morphology and stages of postembryonic development have never been comprehensively reported. Here, 8 morphologically defined stages are described. Size, coloration, and the morphology of wing buds, hind tibial spines, and the ovipositor are the best landmarks for staging. The stages correspond to the 8-12 moult-based instars present in the literature. The staging system aims to standardise studies on the postembryonic development of G. bimaculatus and serve as a point of reference for delineating interspecific postembryonic homologies within Orthoptera.