Menelaus blue morpho

A flash of blue in the forest

The Menelaus blue morpho (Morpho menelaus) is one of the most spectacular butterflies on the planet, a member of the family Nymphalidae. Its wingspan is about 12 cm; the upper surface of the wings is a bright, iridescent blue edged with black, while the underside is brown with prominent eyespots. The blue does not come from pigment but from the microscopic structure of the scales, which refracts and scatters light — so-called structural colour. At rest the butterfly folds its wings, showing only the cryptic brown underside, then flashes open in flight to reveal bursts of blue.

Habitat and range

It lives in the rainforests of Central and South America, particularly the Amazon basin. It favours the understorey and clearings, often flying along trails and watercourses during the brightest hours of the day.

Behaviour and diet

Unlike many butterflies, the adults do not feed mainly on nectar; instead they suck the juices of ripe and rotting fruit, sap and fluids from organic matter. The caterpillars, by contrast, feed on the leaves of various plants and are reddish with markings. The morpho's bobbing, unpredictable flight, alternating flashes of blue and brown, confuses predators.

Did you know?

The nanostructure of its wings is studied by scientists to develop materials, fabrics and displays with structural colour and no pigments. Because of their beauty, these butterflies were widely collected in the 20th century for collections and ornaments.

Conservation

The species has no major species-specific IUCN assessment, but like many tropical insects it depends on the health of the rainforest. Habitat destruction and overcollection remain the main potential threats.