Research on insect cognition has established sophisticated learning, memory, selective information use, and flexible choice in several model systems, but these capacities are often studied as separate traits. This separation can obscure the ecological problem insects actually face: past experience must be retained selectively, current signals differ in reliability and value, internal state alters responsiveness, and actions change the information available next. This integrative review examines how learning mechanisms, memory formation and retention, selective attention, and decision making under uncertainty interact across ecological contexts. Evidence from bees, ants, wasps, and Drosophila shows that cognitive performance is conditional on reinforcement history, stimulus timing, reward composition, social setting, season, and acute thermal stress. Mechanistic studies identify circuit, neuromodulatory, and metabolic contributors in tractable models, but their cross-taxon generality remains unresolved. Field-linked evidence further shows that stronger measured memory is not uniformly beneficial, while null and context-dependent effects caution against interpreting laboratory performance as adaptation or fitness advantage. We therefore propose a context-conditional integration principle in which acquired information, retained representations, selective weighting, and choice are coupled but analytically separable. This synthesis emphasizes inference boundaries among behavioral performance, mechanism, ecological function, and evolutionary consequence, and identifies comparative and multiscale tests needed to connect cognitive process with real ecological demands.
