How do glowworms glow?

Asked by Harry Blythe

Glowworms, a disparate nomenclature for a disparate collection of insects (none are actual worms) glow via a variety of different methods, but all emit light via bioluminescence. Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in the form of light. For example, in phengodes glow is produced and emitted from giant solitary cells within the abdomen, while in arachnocampa it is emitted through modified excretory organs.

In addition, glowworm bioluminescent organs vary widely in size, location and structure, indicating that the different species’ glowing abilities evolved independently of one another. This is supported by the reasons for producing the glow, which range from attracting a mate through to warding off predators and luring prey into sticky webs for consumption, the latter characteristic of the platyura species.