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.
Butterflies in the genus Anastrus are commonly known as Duskywings. They average about 5cms in wingspan. They typically have dark velvety wings with a bluish sheen, convex wing margins, and short antennae.
Anastrus neaeris occurs from Panama to the southern Amazon.
Habitats
This is a lowland rainforest species, found at altitudes between sea level and about 900m.
Lifecycle
The early stages appear to be unrecorded. It is likely however that the lifecycle is similar to that of Achlyodes, as described below :
The eggs of Achlyodes, Anastrus and related genera are usually laid singly on the upperside of leaves of the foodplant.
The caterpillar is likely to be smooth-skinned, green or olive-brown in colour, and marked along the back and sides with a series of thin longitudinal stripes. It is likely to be a nocturnal feeder, and to spend daylight hours at rest within a tent made of leaves spun together with silk.
Adult behaviour
Males are usually seen singly, when imbibing moisture from damp sand, muddy paths, peccary wallows, dry river beds and similar habitats. They are often found amongst mixed aggregations of Achlyodes, Antigonus and other Pyrgines.
Both sexes can also occasionally be seen basking on the foliage of bushes and shrubs in forest edge habitats, or can be disturbed from their resting places beneath leaves.