2022/7/1
On Friday, July 1, the United Nations University Institute for Advanced Studies (UNU-IAS) collaborated with the Kikugawa Community Center to conduct a citizen participation firefly habitat survey tour in Saiwai and Kikugawa district, Kanazawa City. This event, which was also held last year, is part of the SUN Project (Sustainable Urban Nature Project) led by Dr. Juan, a research fellow at UNU-IAS. The participants visited gardens along the Kuratsuki irrigation canal, enjoying urban nature while studying the ecology of fireflies.
Initially, participants gathered at the Kikugawa Community Center, where they received explanations from Dr. Juan and Dr. Tsuda regarding urban nature in Kanazawa and efforts related to sustainable tourism utilizing it. Dr. Juan highlighted the presence of many green infrastructure systems in Kanazawa that leverage nature. He emphasized the necessity to conserve irrigation canals and gardens as part of urban nature and culture, while also introducing activities aimed at conservation. Dr. Tsuda described the collaborative models for maintaining and managing these unique resources of Kanazawa while ensuring sustainable conservation involving various stakeholders and the tourism industry.
Afterward, Mr. Mitsuhide Shinmura (President, Kanazawa Municipal Firefly Association and Secretary General, Ishikawa Prefectural Firefly Association), gave a lecture titled “The Mysteries of Fireflies.” Mr. Shinmura has been involved in activities related to fireflies for nearly 40 years while working at the Kanazawa City Hall on revitalizing satoyama (village forests) and agriculture and forestry. He started the “Firefly Survey” in cooperation with a children’s association in 1957, and this activity has continued to this day. It is said that the case of Kanazawa, where this type of survey has been conducted for over thirty years, is quite rare.
See below the key points discussed in the lecture:
– Origin of the Name “Firefly”: One theory suggests it was named based on the imagery of sparks from torches or will-o’-the-wisps. There was a time when kanji “fire” (火) was read as “ho,” which evolved into “hotaru.” Another theory links the name to “shooting stars.”
– Types of Fireflies: There are about 2,000 species of fireflies globally; Japan has around 50 species mainly in warmer areas, with 7 species found in Ishikawa Prefecture. In Japan, fireflies are typically associated with water’s edge, but most of them are terrestrial in their larval stage. However, the commonly known Genji firefly (Nipponoluciola cruciata) and Heike firefly (Aquatica lateralis) are unique as their larvae live in water.
– Do All Fireflies Glow? Among the 50 species of fireflies in Japan, only 4 species have glowing adults, and only the Genji firefly (Nipponoluciola cruciata) and Heike firefly (Aquatica lateralis) glow continuously from the egg stage throughout their lives.
– Differences Between Genji x Heike Fireflies: Genji and Heike fireflies differ in appearance, emergence timing, and flight patterns. Male Genji fireflies measure about 1.5 cm in length, while females can reach around 2 cm; in contrast, Heike fireflies are slightly less than 1 cm. In terms of markings, Genji fireflies have a characteristic cross-shaped pattern on their backs, whereas Heike fireflies display vertical stripes. Genji fireflies typically emerge in early June, while Heike fireflies appear around mid-July. Although emergence times can vary by location, warming temperatures have generally led to earlier sightings of both types. Genji fireflies emit light at intervals of about 2 seconds as they fly, while Heike fireflies produce light at shorter intervals and tend to fly at lower altitudes.
– Differences Between Males and Females: Males fly around while glowing, and females remain stationary. The females emit signals to attract the males, leading to mating.
– Requirements for Firefly Habitat: It is important for their habitat to have darkness at night, vegetation that provides shade during the day, clean water, stones, sand, and soil, as well as a food source (such as radicine).
– Changes in Firefly Populations: Genji fireflies have experienced a slight increase in habitat due to improved water quality resulting from sewer construction. In contrast, Heike fireflies, which inhabit different areas, have decreased nationally due to abandoned farmland and increased herbicide use. The stone-piled irrigation canals from the Edo period in Kanazawa provide gaps between stones where grass grows, creating a suitable environment for organisms to hide. Therefore, fireflies can be observed within the city.
The presence of a suitable habitat for fireflies indicates that urban nature is rich. Therefore, it is important to collaborate with local communities to carry out activities for firefly conservation.
Observation of Fireflies
After the lecture, participants took firefly maps and walked around the neighborhood.
Many participants expressed surprise that despite walking regularly in the area, they had never seen fireflies so close before. Additionally, fireflies were found not only near the irrigation canals but also in ponds within gardens that draw water from the irrigation system.
Participants recorded and submitted how many fireflies they observed at various firefly observation points.
Through this activity, participants enjoyed the gentle sounds of summer nights while learning about Kanazawa’s urban nature via fireflies. We hope that more people can come to understand the importance of urban nature and biodiversity through such initiatives.
For further details on firefly ecology and the history of firefly habitat surveys in Kanazawa, please refer to “Kanazawa Firefly Map: 30 Years of Progress.”
