Wingless female of some luminous beetles (fireflies) in the family Lampyridae. The luminous organs situated under the abdomen serve to attract winged males for mating. There are about 2,000 species, distributed worldwide.
The luminous larva or wingless grub-like female of a firefly. glow-worm, glow worm

N.Amer. firefly, glowworm.

Firefly.