Microlepidoptera

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.

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.

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