Gelechioidea is the superfamily of moths that contains the case-bearers, twirler moths, and relatives, also simply called curved-horn moths or gelechioid moths. It is a large and poorly understood '"micromoth" superfamily, constituting one of the basal lineages of the Ditrysia.

Microlepidoptera (micromoths) is an artificial grouping of moth families, commonly known as the "smaller moths". These generally have wingspans of under 20 mm, so are harder to identify by external phenotypic markings than macrolepidoptera. They present some lifestyles that the larger Lepidoptera do not have, but this is not an identifying mark. Some hobbyists further divide this group into separate groups, such as leaf miners or rollers, stem or root borers, and then usually follow the more rigorous scientific taxonomy of lepidopterans. Efforts to stabilize the term have usually proven inadequate.