This week, we have a special feature from Sara Lewis, author of Silent Sparks, for Firefly Fact Friday.
By Sara Lewis
Here in the Anthropocene, firefly populations worldwide are threatened by habitat loss and light pollution. Another less widely recognized threat is commercial harvesting of fireflies taken from wild populations. In Japan a hundred years ago, firefly wholesalers harvested millions of Genji fireflies and sold them for their luminous beauty. In the United States fifty years ago, millions of fireflies were harvested and sold to extract their light-producing chemicals. And in China, right now, commercial firefly harvesting is flaring up again in a dangerous new incarnation: firefly theme parks.
In June 2016, a story in the Taiwanese press reported that to entertain customers, North First Park in Chengdu released 100,000 imported fireflies from a large glass box. Hundreds of spectators enjoyed watching escaping fireflies fly up into the night sky and flicker down to the ground. Yet knowledge of firefly biology quickly reveals the ecological disaster behind this seemingly innocent entertainment. The spectators’ glee – along with the fireflies – was short-lived, because adult fireflies only survive for a week or so. Also, fireflies have very specific habitat requirements, so they are not likely to survive outisde their native habitat.
Where did these theme park fireflies come from? We don’t really know. In the past, Chinese organizers of similiar commercial firefly exhibitions have claimed that all the fireflies they released were raised in captivity. Yet to artificially breed 100,000 fireflies from egg to adult would be technically challenging and quite costly. Instead, it seems most likely that all these fireflies had been harvested from wild firefly populations somewhere in China.
Does harvesting a million fireflies matter? Yes. Based on past experience, we already know that overharvesting can put fireflies at risk. During the early 1900s Genji fireflies were nearly extinguished from the Japanese countryside by commercial overharvesting. In the United States, beginning in the 1950s many different firefly species were commercially harvested in massive numbers (surprisingly, this practice persists in some places. While a few very abundant fireflies species might be able to tolerate such heavy harvesting, less common and more localized firefly species would be driven to extinction.
China is a country imbued with much ancient wisdom, vast natural resources, and impressive technological expertise. Yet without some protection, rapid urban growth and economic expansion will inevitably put Chinese fireflies at risk. To conserve fireflies for future generations to enjoy, commercial harvesting from wild populations should be banned, both in China and in the United States.
Learn more about commercial harvesting of fireflies in the U.S. and in Japan in Silent Sparks.