GLOWWORM
glowworm
(noun) the luminous larva or wingless grub-like female of a firefly
Source: WordNet® 3.1
Etymology
Noun
glowworm (plural glowworms)
The larva or wingless grub-like female of a beetle from the families Phengodidae or Lampyridae that gives out a green light from its abdomen.
(AU, NZ) A carnivorous gnat larva in the keroplatid genus Arachnocampa that spins threads to capture insects attracted by its glow.
Source: Wiktionary
Glow"worm`, n. (Zoöl.)
Definition: A coleopterous insect of the genus Lampyris; esp., the wingless
females and larvæ of the two European species (L. noctiluca, and L.
splendidula), which emit light from some of the abdominal segments.
Like a glowworm in the night, The which hath fire in darkness, none
in light. Shak.
Note: The male is winged, and is supposed to be attracted by the
light of the female. In America, the luminous larvæ of several
species of fireflies and fire beetles are called glowworms. Both
sexes of these are winged when mature. See Firefly.
Source: Webster’s Unabridged Dictionary 1913 Edition