What are bright worms?

Bright worms are not really worms, but are actually the larvae of an insect known as a fungal fly. Not to be confused with European fireflies, also called bright worms, mushroom fly larvae are found in caves, caverns and other protected places in Australia and New Zealand. These larvae are the main attractions of these two countries and contribute millions of dollars to the tourism industry every year. Its growing popularity among locals and tourists is not surprising given its interesting past.

Bright worms get their name from their ability to produce light naturally, a process known as bioluminescence. Its blue-green glow is emitted as a result of a chemical reaction between several components: a waste product called luciferin, the enzyme luciferase, an energy molecule called adenosine triphosphate (ATP) and oxygen. Light is used to attract prey such as small snails, mosquitoes, caddis, mosquitoes, May flies, moths and centipedes. In adult females, light shines like a mating call to nearby adult males.

Depending on the environment and food supply, these insects have a life cycle that lasts between 11 and 12 months. There are four stages in the life cycle:

Eggs. Adult females lay an average of 130 eggs. These eggs are laid in groups of 30 to 40 in protected areas such as cracks and crevices. They are cream-colored, about 0.75 mm (0.03 inches) in diameter, and very sticky, allowing them to stick to the walls and ceilings of the cave. As the eggs age, their color becomes darker. The eggs take three weeks to hatch into larvae.

Larvae. Bright worms go from eight to nine months at this stage, the longest compared to other stages of life. The larva begins to shine as soon as it emerges from the egg. It starts between 0.12 and 0.2 inches (3 to 5 mm) long and can grow up to 1.2 inches (3 cm) before pupating.

Bright worms build nests, impressive and organized horizontal tunnels of mucus and silk, from which hang 10 to 70 threads of silk fishing threads measuring between 0.79 and 3.94 inches (20 to 100 mm). Due to the flexibility of their bodies, they can stretch to the length of the untied fishing line and cough up mucus and silk as they move upward to form the line. These threads are covered in sticky drops of mucus that paralyze the prey.

Bright worms live in these lines once they are complete. They move up and down the lines, shining to attract and catch their prey. The more hungry they are, the brighter they are. Worms can feel the vibrations when the prey is trapped and immobilized by mucus drops. They slide into the prey and consume it either by sucking its juice or eating it whole. Once the worms are full of food, they stop emitting light.

Puppets. At the end of the larval stage, bright worms excrete a large amount of mucus around their body. This mucus will eventually dry out and shrink, forming the pupal shell. Prior to this, the threads of the fishing lines are arranged to form a protective barrier within which the pupal shell hangs securely.

During pupation, these insects emit light intermittently. Because the pupal shell is transparent, the emitted glow attracts nearby adult males. This stage lasts about 12 days. Towards the end, the female pupae shine brighter, indicating their preparation for mating.

Adults. Adults resemble mosquitoes, with an average length of 0.59 inches (15 mm). They have a short shelf life as they have no mouth or any other means of subsistence. In fact, their main goals are mating and breeding. Adult males live three to five days, while females only live one or two days, dying shortly after laying eggs.