Greta oto is a species of brush-footed butterfly and member of the subfamily Danainae, tribe Ithomiini, and subtribe Godyridina, known as the glasswing butterfly for its unique transparent wings that allow it to camouflage without extensive coloration.
The part of their wings that seem transparent actually have no coloured scales on them!
Isn’t it simply beautiful! 😍😍😍😍
The glasswing 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. This butterfly thrives in the tropical conditions of the rainforests in the Central and South American countries.
While its wings appear delicate, the butterfly is able to carry up to 40 times its own weight- so they aren’t as delicate as they seem!
In addition to its unique and fascinating wing physiology, the butterfly is known for behaviors such as long migrations and lekking.
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.
The glasswing butterfly is is one of the most abundant butterflies in its region and is spotted more often than some of its relatives in Central America. It can be found all year long, but month to month a population can fluctuate.
They lay their eggs typically laid on plants of the genus Cestrum, a member of the nightshade family of plants, which serves as a food source for later life stages.
Below are some examples of plants from the genus Cestrum.
The caterpillars of the glasswing butterfly have green bodies with bright purple and red stripes. The larvae are cylindrical in shape with dorsal projections that are smooth with filaments. These properties make the larvae extremely reflective, which essentially causes them to be invisible to predators.
The pupae are silver in colour and during the fifth instar stage (see butterfly reproductive cycle below), the pupa produces a silk pad on the lower surface of leaves through four spinning movements, onto which it attaches.
The silk fibers are important in providing greater flexibility to the pupa attachment. The cremaster, a hooked bristle-like structure on the pupa, attaches to this silk pad by a series of lateral movements of the pupa’s posterior abdomen.
The silk pads are essential for the pupas, attachment failure occurs when the silk pad breaks.
Researchers have found that the pupa attachment to have high tensile strength and toughness, which actually prevents the pupa from being pulled by predators or breaking off in the wind, allowing them to safely swing and move whilst attached safely to the host plant.
Birds are the most common predators of this butterfly. The glasswing combats predators by consuming toxins through plants of genus Cestrum and family Asteraceae in both the caterpillar and butterfly stages. Toxin consumption gives the butterfly a foul taste that discourages predation. It also utilizes its transparency to hide from predators by camouflaging into the background during flight. Transparency is a rare trait among Lepidoptera, since they more commonly use mimicry to ward off predators
To find a mate, males congregate in shady corners of a forest and give off these pheromones to “call” females. The long hairs that males have tucked away help magnify how stinky they are, sort of the way hair makes an armpit smell stronger. Females smell the males and join the congregation to find a mate.
In order to attract females, male butterflies form leks, or large gatherings where males compete for mates. They gather in shaded areas of the rainforest and competitively display themselves in order to attract mates. Male glasswing butterflies release pheromones during lekking in order to attract females.
The pheromones produced are derived from pyrrolizidine alkaloids that the butterflies obtain through their diet of plants of the family Asteraceae. The alkaloids are then converted to pheromones through the formation of a pyrrole ring, followed by ester cleavage and oxidation.
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.