Anteros formosus

Identity

Anteros formosus is a metalmark butterfly in Riodinidae. [2]

Appearance

The dark upperside has a conspicuous white forewing patch. Beneath, cream areas contrast with reddish-brown lines and spots, with greenish reflections on parts of the pattern. Males and females have similar wing markings. [1]

Range and habitat

In Costa Rica's Guanacaste region, it inhabits rainforest understory and openings along paths and forest margins. [1]

Life cycle

The pupa retains a covering of larval hairs. Guanacaste rearings recorded a pupal period of approximately 8–15 days. [1]

Food and host plants

Guanacaste hosts include Conostegia xalapensis and several Miconia species in Melastomataceae, together with Vochysia guatemalensis and V. ferruginea in Vochysiaceae. [1]

Behaviour

Adults fly during daylight. The caterpillars occur singly on their host plants. [1]

Remarkable detail

Mature larvae carry long, white, branched setae and a row of orange, balloon-shaped setae on the shield behind the head. Clusters of perforated cupola organs lie near the spiracles, the respiratory openings along the body. [2]

Artwork

Male · Ventral view.Illustration adapted from Anteros formosus specimen photograph by Área de Conservación Guanacaste / Janzen–Hallwachs inventory (DHJ voucher photograph). CC BY 4.0.

Anteros formosus, male ventral view — Male · Ventral view.Illustration adapted from Anteros formosus specimen photograph by Área de Conservación Guanacaste / Janzen–Hallwachs inventory (DHJ voucher photograph). CC BY 4.0.

Sources

Anteros formosus (Riodinidae) ↗
Área de Conservación Guanacaste · Accessed 2026-10-13
Last instar larvae and pupae of Ourocnemis archytas and Anteros formosus ↗
Zootaxa / Universidade Estadual de Campinas · Accessed 2026-10-13

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