Photo Essay Photo Essay

Photographer: Lawrence Gilbert

Evolution: Passionflower butterflies

Passifloras have evolved many defenses in response to their main enemies, the passionflower butterflies, or heliconiines. These insects lay their eggs only on passionvines and the resulting caterpillars eat the leaves as they emerge from the cocoon. They search visually for the vines, resulting in intense selection pressure on the appearance and behavior of the plants. There is also much diversity in chemical, particularly cyanogenic, defenses. This is the heliconiine butterfly fauna of Corcovado National Park, Costa Rica, shown with the leaves of the species they eat.