Got some hits recently from people looking for information about Muju's annual firefly festival (무주반딧불축제). This year it opened on June 3rd and will run from June 11th, in Jeollabuk-do's Muju county.
Both posters taken from the official festival website, making a strong push to win the award for "Most pop-ups on a website in 2011."
I've written about it several times in the past
* June 4, 2008: 2008 Muju Firefly Festival: June 7th - June 15th.
* June 16, 2008: 2008 Muju Festival
* June 2, 2009: 2009 Muju Firefly Festival (2009 무주반딧불축제)
and said that although it's special to me because it's where I went with my wife on our first date (awww), I didn't see a single firefly. Though one obscure poet wrote that it was the Japanese who exterminated the fireflies---a poem known only because it turned up deep in the Google search results---the scarcity is actually due to climate change, as Kim Jong-Gill at the National Institute of Agricultural Science & Technology wrote in a 2002 issue of Koreana (.pdf file)
Only 20 to 30 years ago fireflies were a common sight, but now they have become a nostaligic rarity, highlighted on television shows. In recent years, their natural habitats have been increasingly destroyed and disturbed through environmental damage resulting from the modernization of rural areas and changes in agricultural methods involving excessive reliance on pesticides and chemical fertilizers, as well as street lights that interfere with the ability of fireflies to communicate with each other. Indeed, with all these challenges to its survivability, it is no wonder that firefly sightings are so infrequent nowadays.
Commenters have also written on this site that the appearances are hit-or-miss depending on the weather.
The festival is held in the county seat, Muju-eup, accessible from Jeollanam-do by buses that run to Muju by way of Namwon, Jangsu, and other smaller towns along the way. There are seven buses a day from Gwangju, with three leaving in the afternoon: 13:20, 15:00, and 17:00. One big improvement festival organizers could make, besides getting more fireflies, would be to operate shuttles between Muju-eup and neighboring cities. Going to and from the festival is a challenge without your own transportation, since the last bus leaves Muju rather early, and the few motels in town aren't enough to accommodate the thousands of visitors.