Skipper (butterfly) - Description and Systematics

Description and Systematics

The Hesperiidae are placed in a monotypic superfamily Hesperioidea. This is because they form a lineage apart from other Rhopalocera (butterflies), which mostly belong to the typical butterfly superfamily Papilionoidea. The third and rather small butterfly superfamily are the moth-butterflies (Hedyloidea) which are restricted to the Neotropics. Hesperioidea is very likely the sister group of Papilionoidea, and together with Hedyloidea they constitute a natural group (clade). Collectively, these three groups of butterflies share many characteristics, especially in the egg, larval and pupal stage.

However, skippers have the antennae clubs hooked backward like a crochet hook, while the typical butterflies have club-like tips to their antennae, and moth-butterflies have feathered or pectinate (comb-shaped) antennae similar to "moths". Skippers also have generally stockier bodies and larger compound eyes than the other two groups, with stronger wing muscles in the plump thorax, in this resembling many "moths" more than the other two butterfly lineages do. But unlike for example the Arctiidae, their wings are usually small in proportion to their bodies. Some have larger wings, but only rarely as large in proportion to the body as in other butterflies. When at rest, skippers keep their wings usually angled upwards or spread out, and only rarely fold them up completely.

The wings are usually well-rounded with more or less sharply-tipped forewings. There are some with prominent hindwing tails, and others have more angled wings; the skippers' basic wing shape varies not much by comparison to Papilionoidea however. Most have a fairly drab coloration of browns and greys; some are more boldly black-and-white. Yellow, red and blue hues are less often found, but some largely brown species are quite rich-colored too. Green colors and metallic iridescence are generally absent. Sexual dichromatism is present in some; males may have a blackish streak or patch of scent scales on their forewings.

Many species of skippers look frustratingly alike. For example, some species in the genera Amblyscirtes, Erynnis (duskywings) and Hesperia (branded skippers) cannot currently be distinguished in the field even by experts. The only reliable method of telling them apart involves dissection and microscopic examination of the genitalia, which have characteristic structures that prevent mating except between conspecifics.