Greta Oto eggs hatch underneath Cestrum nightshade flowers. The caterpillars instantly feast on the highly poisonous plant. Their bodies are genetically modified to digest and assimilate the alkaloid compound directly into their own cells. This makes the caterpillars indigestible and an unwanted prey.
The G. Oto caterpillars form silver metallic chrysalids during their pupa stage. This coloration gives a raindrop camouflage for protection while they undergo complete metamorphosis.
As adults G. Oto emerge with a single purpose of completing a long mating migration. Adult males participate in lekking, a competitive assemblage to fight for female affection. Once fertilized, adult females return to a Cestrum plant to lay her eggs and repeat the cycle.
As a whole, the lifespan of a Greta Oto from egg til death takes about ten months. Like most butterflies, G. Oto cannot withstand the cold of winter. As the seasons change the entire species dies out only to be revived by the newest generation hatching in the spring.