Despite their deceptive name, fireflies—or lightning bugs—are not true flies at all, but rather fascinating, soft-bodied beetles belonging to the family Lampyridae. They are universally celebrated for their mastery of bioluminescence, a chemical process that yields a remarkably efficient “cold light,” used to ward off predators, whisper signals in the dark, and attract potential mates. I encountered this delicate specimen on the wild, humid edge of the Amazon rainforest in Puyo, Ecuador. It belongs to the diverse genus Photinus, whose representatives share many physical similarities and can be notoriously difficult to differentiate. While North American species of this genus are incredibly common and extensively photographed, their tropical counterparts—especially those hidden away in more remote regions—remain largely mysterious and challenging to identify.