thumb|300px|Imperial moth (Eacles imperialis) development from egg to pupa, showing all the different instars
thumb|300px|Imperial moth (Eacles imperialis) development from egg to pupa, showing all the different instars
An instar (; ) is a developmental stage of arthropods, such as insects, which occurs between each moult (ecdysis) until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).