Greta oto is a species of brush-footed butterfly and member of the subfamily Danainae, tribe Ithomiini, and subtribe Godyridina. It is known by the common name glasswing butterfly for its transparent wings, which allow it to camouflage without extensive coloration. In Spanish-speaking regions, it may also be referred to as espejitos, meaning "little mirrors" because of its transparent wings. The butterfly is mainly found in Central and northern regions of South America, with sightings as far north as Texas and as far south as Chile. While its wings appear delicate, the butterfly is able to carry up to 40 times its own weight. In addition to its wing physiology, the butterfly is known for behaviors such as long migrations and lekking. Greta oto closely resembles Greta andromica.
The glasswing butterfly is most commonly found from Central to South America as far south as Chile, with appearances as north as Mexico and Texas. This butterfly thrives in the tropical conditions of the rainforests in the Central and South American countries.
The glasswing butterfly is migratory and travels up to 12 miles (19 km) per day at speeds of up to 8 miles per hour (13 km/h). It migrates in order to change elevations, and this migration causes there to be population density differences in varying geographical areas.
This butterfly species mates polygynously, with males attempting to obtain one or more female mates per breeding season.
The following national parks of Costa Rica currently feature the glasswing butterfly and are working on their conservation: Guanacaste National Park, Rincón de la Vieja National Park, Monteverde Cloud Forest Reserve, Palo Verde National Park, Carara National Park, Poás Volcano National Park, La Selva Reserve and Biological Station, Juan Castro Blanco National Park, Irazú Volcano National Park, Chirripó National Park, and La Amistad International Park.
