Gelechioidea
Gelechioidea (from the type genus "Gelechia", "keeping to the ground") 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. As of the 1990s, this superfamily was composed of about 1,425 genera and 16,250 species. It was estimated that only 25% of the species diversity of Gelechioidea had been described. If this estimate is accurate, Gelechioidea will be one of the largest superfamilies of Lepidoptera. The name "curved -horn moths" refers to one of the few conspicuous features found in (almost) all Gelechioidea, and, at least in the more extreme developments, unique to them: the labial palps are well-developed (though not thickened), and form more or less gently curved protrusions whose end has a drawn-out, pointed tip. Their proboscis is generally well-developed, allowing for long-lived imagines (adults); the proximal part of the proboscis is scaly. Otherwise, the Gelechioidea vary extensively in habitus; most have small hind-wings with long, hairy fringes, though these are not easily seen in the living animal as they are  tucked under the fore-wings at rest. The body is usually quite compressed, either dorsoventrally or laterally. Families. The phylogeny and classification of the Gelechioidea remains a subject of considerable dispute. For example, the Elachistidae were at one time used as a sort of "wastebin taxon" to unite as subfamilies a variety of plesiomorphic members of this superfamily, which do not actually seem to form a monophyletic group. Many of these have now been moved to the Oecophoridae, but others are almost certainly likely families in their own right, while additional ones may well be so. In 2011 the superfamily  was divided into 21 families, based mainly on morphological studies, with adjustments made for some molecular studies. The number of genera and an estimate of the species number are given in parentheses. However, a later phylogenetic analysis of the Gelechioidea, using a morphological and molecular dataset, proposed a revision into 16 families, with the status of two further families, Schistonoeidae and Epimarptidae, unclear. References. See also for comparison of some approaches to gelechioid systematics and taxonomy.