firefly

Firefly, also known as a lightning bug, is a common name for beetles in the family Lampyridae, within the order Coleoptera. There are about 2,000 described species worldwide, occupying a range of habitats from forests and wetlands to meadows and urban areas. Despite the name, fireflies are insects, and they are not flies.

Bioluminescence: Fireflies produce light through a chemical reaction in specialized light-emitting organs in the abdomen. The reaction involves luciferin, luciferase, ATP, and oxygen, emitting light with very little heat. The glow is typically yellow-green, though colors and intensities vary by species. Light signals are primarily used for courtship, with species-specific flash patterns and timing. In many species, males fly and flash while females may respond from vegetation; in some groups, wings of females are reduced or absent and the glow serves to attract mates from a perched position.

Life cycle and biology: Fireflies undergo complete metamorphosis—egg, larva, pupa, and adult. Eggs are laid in soil or leaf litter; larvae, often called glowworms, are usually predatory on invertebrates such as snails and slugs and may glow as well. Pupation occurs in soil or debris. Adults typically live only a short time and focus on reproduction; diets vary by species, with some adults feeding on nectar and others not feeding at all. Predatory species, such as certain Photuris, may mimic firefly signals to lure and prey on other fireflies.

Ecology and conservation: Fireflies favor warm, humid habitats with varying vegetation and low light pollution. They are sensitive to habitat loss, pollution, and artificial lighting, and several regions report declines. Conservation efforts emphasize preserving natural habitats and reducing light pollution to support firefly populations.