Glasswinged Butterfly

glass-winged butterfly with flower visible through it
glass-winged butterfly with flower visible through it

Order: Lepidoptera
Family: Nymphalidae
Subfamily: Danainae
Genus: Greta
Species: G. oto
Common name: Glass-winged Butterfly

A fascinating insect in the order Lepidoptera is the glass-winged butterfly, Greta oto. Glass wings are brush-footed butterflies in the family Nymphalidae and subfamily Danainae. The butterfly gets its common name from the glass-like transparent tissues on its wings, which lack the colored scales usually seen in members of the order Lepidoptera. The glass-winged butterfly is one of few terrestrial organisms that demonstrate transparency.

glass-winged butterfly caterpillar munching on a leaf
glass-winged butterfly caterpillar munching on a leaf
reflective chrysalis of the glass-winged butterfly
reflective chrysalis of Greta oto

Like all members of Lepidoptera, glass wings are holometabolous. This means that they go through a life cycle consisting of an egg, larvae, pupae, and adult. Adult females lay her eggs in singles on the underside of leaves from the Cestrum family, commonly known as the Nightshade, a highly poisonous plant. Once they hatch, the red and purple caterpillars gorge themselves on the leaves of the plant. They then pupate and become a chrysalis. The chrysalis is as reflective as a mirror, which is beneficial because it can reflect its surrounding habitat to blend in or appear to be a droplet of water to predators. The adult then emerges and feeds on the nectar of flowers from the Lantana genus. The adult butterflies have a long life span of anywhere from 6 to 12 weeks.

distribution of the glass-winged butterfly
the red shows the distribution of the glass-winged butterfly Greta oto

Glass-winged butterflies are terrestrial insects that are distributed throughout Central America, especially in Costa Rica, but have also been found as far north as Florida. They can be found in warm, rainy, humid forests with ample flowering plants. The glass wings migrate long distances, but can be found year-round in Costa Rica. Glass-winged butterflies can fly at speeds of up to 8 miles per hour and have been documented to fly 12 kilometers, or 7.5 miles, in one day. Greta oto is one of the most abundant butterflies of a small monophyletic clade of butterflies with clear wings. This butterfly is not registered on the IUCN Red List of Threatened Species.

The most notable characteristic of the glass-winged butterflies is its clear wings. The transparent wings help the butterfly blend in with the environment to avoid predators while in flight and while at rest. In order for its wings to be transparent, the tissues of the wings must not absorb light. The irregular structure of the butterfly wing causes little to no reflection of light, causing the glass-like effect on the wings of the butterfly. This irregular structure has even been a source of biomimicry to create anti-reflective coatings for technology.

The clear wings of the glass-winged butterflies are not its only defense mechanism. All of the plants the glass wings feed on as adults and immatures contain alkaloids that are toxic to its predators. The compounds are stored in the caterpillar’s body after eating and are retained through metamorphosis into adulthood. Because of this, both the caterpillars and the adults are toxic, making them distasteful to predators and can even cause sicknesses. The glass wing caterpillars’ bright red and purple coloration warn predators of their toxicity.

The male glass wings also use the alkaloids found in their food to produce sex pheromones. These pheromones are released when the males lek in order to find a mate in the forest, meaning they gather in large groups to show off for females to attract females. Male glass-winged butterflies have also been shown to be very territorial.

glass wing adult feeding on nectar
glass wing adult feeding on nectar

Want to try raising your own glass-winged butterflies? The pupae can be purchased online for a mere £18, or a little more than $27. You can even find information that can help you breed your butterflies after they hatch!


References:

“15 Stunning Photos of the Glasswinged Butterfly.” TwistedSifter. 16 Mar. 2012. Web. 30 Nov. 2015. <http://twistedsifter.com/2012/03/15-stunning-photos-of-the-glasswinged-butterfly/>.

Coombes, Simon. “Greta Oto – Glasswing.” Captain’s European Butterfly Guide. Web. 30 Nov. 2015. <http://www.butterfly-guide.co.uk/farms/helic_ithom/hel8.htm>.

“Glasswing, the Transparent Butterfly.” Strange Animals. 28 Feb. 2011. Web. 30 Nov. 2015. <http://www.strangeanimals.info/2011/02/glasswing-transparent-butterfly.html>.

“Gorgeous Glasswing Butterflies (42 Stunning Photos).” Love These Pics. 29 Mar. 2013. Web. 30 Nov. 2015. <http://www.lovethesepics.com/2013/03/gorgeous-glasswing-butterflies-42-stunning-photos/>.

“Greta Oto.” Giardinauta. Web. 30 Nov. 2015. <http://www.giardinauta.it/greta-oto-farfalla-dalle-ali-di-vetro/>.

IUCN Red List of Threatened Species. Web. 30 Nov. 2015. <http://www.iucnredlist.org/>.

Jenkins, Nathaniel. “Featured Creature: Glasswinged Butterfly.” PBS. PBS, 12 Aug. 2104. Web. 30 Nov. 2015. <http://www.pbs.org/wnet/nature/blog/inside-nature-featured-creature-glass-wing-butterfly/>.

Strieter, Amy. “Glasswing Butterfly.” Anywhere Costa Rica. Web. 30 Nov. 2015. <http://www.anywherecostarica.com/flora-fauna/invertebrates/glasswing-butterfly>.

“The Incredible Glasswing Butterfly.” The Ark In Space. 25 Oct. 2014. Web. 30 Nov. 2015. <http://www.arkinspace.com/2011/07/incredible-glasswing-butterfly.html>.