Butterflies of Zihuatanejo

SUPERFAMILY PAPILIONOIDEA

-Subtribe Eudamina

-Brown Longtail (Spicauda procne)

The Brown Longtail (Spicauda procne), formerly known as Urbanus procne, is a common and distinctive member of the spread-wing skipper family (Pyrginae). It is best known for the long, elegant "tails" on its hindwings and its unique habit of resting with its wings spread flat. The upper side is a consistent chocolate brown or greyish-brown, often with subtle darker brown bands. Unlike many other longtails, it lacks the white or translucent spots on the forewings.

Diet

Caterpillars feed on grasses (Poaceae).
Larvae feed within shelters formed from grass leaves.
Adults visit flowers for nectar and may also take moisture from damp ground.

Range

Spicauda procne has a broad range from Mexico through Central America and across much of South America to Argentina.
It occurs in western and southern Mexico, including Guerrero, and is found in the Zihua area.

Habitat

It occurs in tropical and subtropical forest edges, grasslands, fields, roadsides, clearings and secondary vegetation.
Areas with abundant grasses provide suitable habitat for the larvae.
In the Zihua area, it is most likely in sunny grassy openings, disturbed areas and forest margins.

Description

A medium-sized long-tailed skipper with a wingspan of approximately 37–48 mm.
The upper surface is predominantly dark brown, with relatively subdued markings.
The hindwings have long, narrow tails, while the wing fringes are distinctly tan and lack the strong white checking seen in some similar Spicauda.
Males generally lack the prominent white forewing spots found in Spicauda teleus.
Some females have a narrow pale postmedian band on the forewing and can consequently resemble S. teleus.
The underside is brown to reddish-brown with pale markings and a characteristic subdued appearance.