AbstractTrait matching between mutualistic species is usually expected to maintain mutualism, but empirical studies of trait complementarity and coadaptation in multi‐species assemblages—which represent the reality of most interactions in nature—are few. Here, we studied trait matching between the leafflower shrubKirganelia microcarpaand three associated seed‐predatory leafflower moths (Epicephalaspp.) across 16 populations. Behavioral and morphological observations suggested that two moths (E. microcarpaandE. tertiaria) acted as pollinators while a third (E. laeviclada) acted as a cheater. These species differed in ovipositor morphology but showed trait complementarity between ovipositor length and floral traits at both species level and population level, presumably as adaptations to divergent oviposition behaviors. However, this trait matching varied among populations. Comparisons of ovipositor length and floral traits among populations with different moth assemblages suggested an increase of ovary wall thickness where the locular‐ovipositing pollinatorE. microcarpaand cheaterE. laevicladawere present, while stylar pit depth was less in populations with the stylar pit‐ovipositing pollinatorE. tertiaria. Our study indicates that trait matching between interacting partners occurs even in extremely specialized multi‐species mutualisms, and that although these responses vary, sometimes non‐intuitively, in response to different partner species. It seems that the moths can track changes in host plant tissue depth for oviposition.