Introduction
The Pyrginae, popularly known as Flats or Spreadwings, are a cosmopolitan subfamily distributed across temperate and tropical habitats throughout the world. In the Americas there are 990 species, of which about 580 are assigned to the tribe Pyrgini.
The suffused but distinct markings, and the 3 whitish spots near the acute apex clearly identify the illustrated butterfly as a member of the genus Nisoniades, but with 33 species in the genus, most of which are very similar in appearance, determining the identity of a species from a photograph is not always easy. I’m fairly confident however in my determination of the illustrated butterfly as being a male of rubescens.
It should be noted that there is another neotropical skipper genus with an almost identical name – Niconiades ( Hesperiinae ).
Nisoniades rubescens is distributed from Mexico to Bolivia and northern Argentina.
Habitats
This species is found in tropical and subtropical evergreen rainforest at altitudes between about 200-1400m.
Lifecycle
I have no information regarding Nisoniades, but Pyrgine butterflies typically lay their eggs singly on either the upperside or underside of leaves. The larvae are usually dull green or brownish, with thin longitudinal lines along the back and sides, and with black shiny heads. Most feed on low growing herbaceous plants, but a small percentage feed on the leaves of bushes or trees. The pupae are usually dark and smooth, with the wing cases in a contrasting tone or colour. They are normally formed within silken tents formed by spinning together the leaves of the foodplant.
Adult behaviour
This butterfly, and other Nisoniades species, are generally encountered as solitary males, which tend to be seen basking on the foliage of shrubs, or imbibing mineralised moisture from river sandbanks – often in the company of Ebrietas anacreon, Gorgopas trochilus, Antigonus nearchus and other Pyrgine skippers.