Butterflies of Zihuatanejo

SUPERFAMILY PAPILIONOIDEA

-Subtribe Telemiadina

-Subgenus Ectomis

-Asine Longtail (Ectomis asine)

Ectomis asine, commonly known as the Asine Longtail, is a large and distinctive skipper butterfly in the family Hesperiidae. It is easily recognized by its long, tail-like extensions on the hindwings, a feature that gives it a graceful, almost swallowtail-like appearance. The upper side of the wings is typically dark brown to black, marked with small pale or translucent spots, especially on the forewings. The underside is lighter brown with subtle patterning, helping the butterfly blend into its surroundings when resting. Its robust body, hooked antennae, and strong, rapid flight are characteristic of skippers.

Diet

Caterpillars feed on leguminous trees and shrubs (Fabaceae).
The larvae feed within shelters made from leaves, a common strategy among many Eudaminae skippers.
Adult butterflies visit flowers for nectar and may be seen actively flying along sunny woodland edges.

Range

The Asine Longtail ranges from Mexico through Central America to Panama, with some taxonomic treatments extending its range southward into northwestern South America.
It occurs in Guerrero and is within its expected range in the Zihua area, particularly in warm woodland and forest-edge habitats.

Habitat

It inhabits tropical and subtropical woodland, seasonally dry forest, forest edges, clearings, and secondary vegetation.
Its association with Lonchocarpus and other legumes makes wooded edges and areas of regenerating vegetation particularly suitable.
Around Zihua, it would be most likely along sunny forest margins, dry tropical woodland, stream corridors, and areas where leguminous trees are abundant.

Description

A medium-sized long-tailed skipper with a wingspan of approximately 42–43 mm.
The wings are predominantly dark brown, with several small, translucent to whitish spots on the forewing.
Males have relatively short tails on the hindwings, typically about 7–8 mm, compared with some closely related species.
The forewing has four apical spots, an important feature for distinguishing it from the closely related Mexican Longtail (Ectomis mexicanus), which generally has five.
The underside is somewhat paler and mottled, providing effective camouflage among dried leaves and vegetation.
Its dark coloration, relatively short tails, and small pale wing spots give it a more subdued appearance than many of the brightly marked longtail skippers.