This story initially appeared on Atlas Obscura and is a part of the Climate Desk collaboration.

At the third assembly of the Moriyama City Firefly Forest Museum’s eight-week Firefly Course, a conservation coaching program for adults, egg assortment begins. Each feminine Genji firefly, Nipponoluciola cruciata, can lay up to 500 of the caviar-like orbs, fastidiously depositing them throughout the mossy banks of rivers and streams in blankets of pale yellow.

In the wild, solely a tiny fraction of the eggs survive. River pollution, flood prevention measures, overfishing, and extra city mild devastated the insect’s inhabitants within the twentieth century. But on the museum, synthetic breeding and rearing strategies will coax 30,000 Genji fireflies into larvae, a part wherein they dwell like tiny, voracious underwater explorers.

Each month, the ten college students of the Firefly Course return to the museum to be taught in regards to the breeding and rearing methods of the Genji and their main meals supply, freshwater snails (Thiaridae). “Hundreds of thousands of water snails are required” to feed the larvae, explains Firefly Forest Museum director and Firefly Course instructor Michio Furukawa. They’ll assist the fireflies multiply as much as 20 instances between delivery and maturity, rising in size from the thickness of a grain of rice to the diameter of a penny.

By the scholars’ seventh assembly, about 5,000 of the hatchlings can have survived lengthy sufficient to be launched from their breeding tanks into the museum’s man-made river in February. Only the heartiest of the bunch will attain the ultimate stage of maturity, the one which glows.

Thirty years in the past, when the Moriyama City Firefly Forest Museum first opened, the long run appeared darkish for the revered Genji firefly, whose populations had barely begun to get well greater than six a long time after Japanese conservationists acknowledged that their lights had been going out. It wasn’t at all times this manner, particularly in Moriyama, the place swift rivers and pristine natural banks made for the best Genji habitat.

In Japan, fireflies have lengthy been the harbingers of summer season, taking to the skies in June and July in a flickering dance of courtship that lights up the evening. Moriyama’s Genjis had been particularly prized for his or her vivid, yellow-green glow, drawing vacationers from across the nation by not less than the mid-Nineteenth century.

But finally, intrepid entrepreneurs realized that they might make more cash by capturing and transport the tiny bugs from Moriyama to inhabitants facilities like Osaka, Kyoto, and Tokyo than they might by ready for urbanites to come back to them. Throughout Japan’s Meiji interval, which stretched from 1868 to 1912, a commercial firefly industry gorged on the colonies rising from Moriyama’s waterways.

In only one evening, a single firefly hunter could capture as many as 3,000 of their prey, scraping the earth with bamboo brushes to frighten just-mated, egg-laying Genji from the riverbanks. The subsequent morning, the bugs had been fastidiously packaged and shipped off to kind the luminous blinking decor at fancy inns, eating places, and personal gardens. For years, it was Moriyama’s fireflies that had the honour of being introduced to Emperor Meiji as a valuable reward which, in Japanese tradition, symbolizes passion and the fleeting impermanence of all living things.