Microlepidoptera (micromoths) is an artificial (i.e., unranked and not monophyletic) grouping of moth families, commonly known as the 'smaller moths' (micro, Lepidoptera). These generally have wingspans of under 20 mm, and are thus harder to identify by external phenotypic markings than macrolepidoptera. They present some lifestyles which 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. Diversity Vernacular usage divides the Lepidoptera simply into smaller and larger or into more-primitive and less-primitive groups: microlepidoptera and macrolepidoptera, respectively. Intuitively, the "micros" are any lepidopteran not currently placed in the macrolepidoptera. This paraphyletic assemblage, however, includes also the superfamilies Zygaenoidea, Sesioidea and Cossoidea that would in common parlance normally be lumped with the "macros". A lepidopterist might call these groups 'primitive macros'. Furthermore, even all of the nonditrysian moths are not small. For example, the Hepialidae or "swift moths" (up to 25 cm wingspan) fall quite basally in the lepidopteran "tree of life". The recently discovered primitive superfamily Andesianoidea is another case in point: lurking within the Cossoidae until 2001, these moths have up to an order of magnitude greater wingspan (5.5 cm) than most previously known monotrysian "micros". Whilst the smaller moths are usually also more seldom noticed, a more expansive "non-macrolepidopteran" concept of the microlepidoptera would include about 37 out of the approximately 47 superfamilies. Whilst usually less popular, micros are thus more important in the sense that they include a much wider span of the "tree of life" (i.e., phylogenetic diversity). Whereas they include no butterflies, micros do also include a surprising number of day-flying groups, and the advent of online identification resources in many countries (e.g. "UK moths") combined with the widespread use of digital macrophotography, is making them much easier to identify. Life style Microlepidoptera can be found in a broad variety of habitats and ecological niches worldwide, both terrestrial and freshwater aquatic (e.g. Acentropinae). They have a wide variety of feeding habits in both larval and adult life stages. Caterpillars feed on a wide variety of plant tissue and across a wide spectrum of plant groups from liverworts to angiosperms. They are either external feeders ("exophagous") or more usually feed internally ("endophagous"), typically