Consistent behavioral differences among individuals are increasingly documented in insects, yet evidence of repeatability is often interpreted more broadly than the underlying designs permit. In particular, short-term behavioral consistency can be conflated with persistence across developmental stages or environments, and associations with physiological performance, task allocation, survival-related outcomes, or reproduction can be interpreted as evidence of generalized fitness advantage. This systematic review evaluates insect-personality research published from 2017 through 2021 with emphasis on three linked questions: whether behavioral differences remain repeatable when contexts change, how environmental and developmental conditions alter behavioral means and variance structures, and when repeatable behavior can legitimately be connected to ecological or fitness-relevant outcomes. Evidence was coded by taxon, life stage, sex, behavioral operationalization, measurement setting, level of biological organization, repeated-measures design, environmental context, and outcome class. The literature demonstrates repeatable behavioral differences in multiple insect systems but also reveals marked stage, trait, sex, environmental, and analytical dependence. Complete metamorphosis can disrupt cross-stage rank consistency; stable local environments can inflate apparent individuality; developmental, social, anthropogenic, nutritional, and physiological conditions can alter means, repeatability, covariance, or their interpretation without changing all components in parallel. Fitness relevance is therefore not a property that follows automatically from repeatability. We propose that insect personality be interpreted through separate evidential stages: demonstrated among-individual consistency, transport across contexts, ecological association, and direct fitness or evolutionary inference.
