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The railroad worm is a larva or larviform adult of beetles of the genus Phrixothrix in family Phengodidae, characterized by their unique possession of two different colors of bioluminescence. Their body can glow green, while their head can glow red; this is due to two different kinds of luciferin and luciferase in their bodies. This is believed to be an adaptation to help confuse and frighten predators.
The Apple Maggot may also be called "railroad worm".
