This odd creature is an adult phengodid beetle. More commonly, these are known as glowworms as the larva and adult females (which are larva-like in appearance), but not the adult males (shown here) are usually bioluminescent. Males are attracted to females at a distance by pheromones, hence the feathery antennae to detect the faint chemical traces, but find their mates at close range by the female's bioluminescence. Glowworm larvae are predacious and specialize on millipedes.