The distribution of rare butterflies in Eastern Denmark has plummeted by 72% in just 26 years, researchers report.

For one species of butterfly, a vision gene's jump onto a sex chromosome explains why males and females see color differently.

When oleander aphids invade milkweed, monarch butterflies lay fewer eggs and caterpillars take longer to mature, a new study shows.

More and larger spots may help monarch butterflies survive their long migration. The spots may change airflow patterns around their wings.

Unseasonably warm and cold days can prolong the active period of moths and butterflies by nearly a month. "The results are not at all what we expected."

Scientists have discovered where the first butterflies originated and which plants they relied on for food.

Botanical gardens and other urban green spaces can hold surprising diversity, according to a new study that shows they're key for butterflies.

A debilitating parasite is invading the guts of monarch butterflies, researchers say. "It's a signal that something is not right in the environment."

How did eyespots on butterfly wings evolve? By recruiting gene networks already at work in the body to build antennae, legs, and even wings, research finds.

Researchers used a nano-3D printing method to recreate the brilliant structural color of butterfly wings. It could pave the way for new screen technology.