Habiting in Tsushima Island, the Korean Peninsula

AKIMADO - BOTARU

Language : Japanese

 

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In the autumn of the island, the spiderwort makes a pretty flower bloom like a firefly. When a night curtain drops, we can see many stars in the sky at night. There are shining innumerable fire to lure fish overlooking the sea and the fireflies flying around. They are pastimes that give poetic charm to autumn only in Tsushima, Nagasaki prefecture.

It's Insecta - Coleoptera - Lampyridae - Pyrocoelia and the ground firefly of the Asian continent which is inhabiting only Tsushima in Japan. Akimado-botaru was named from it is seen fly in autumn, acturelly autunm is "Aki " in Japanese. The ecology is remarkably different from other kinds. It's biologically and geographically in an extremely valuable existence. The habitat of Azu abandonment area in Izuhara was designated as a special natural treasure by Nagasaki Prefecture in 1966.

Shozaburo Watase named Akimado-Botaru and announced it, and Matsumura Matsudaira announced it later first with other Pyrocoelia.


Notes :
The Japanese phenomenon that the first syllable of the following word varies when a word compounds.
e.g. : Akimado + hotaru (firefly) = Akimado-botaru
Jp: = Japanese Name


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The fireflies of five kinds of three genus, Luciola cruciata Motschulsky (Jp: Genji-botaru), Luciola lateralis Motschulsky (Jp: Heike-botaru), Lucidina biplagiata (Jp: Oba-botaru), Luciola tsushimana Nakane (Jp: Tsushima-hime-botaru), Pyrocoelia rufa E. Olivier (Jp: Akimado-botaru), inhabit Tsushima island. (cf. firefly of Tsushima).

Luciola cruciata Motschulsky (Jp: Genji-botaru) which can only inhavit the clear stream can be watched everywhere in the river except a river flowing through the downtown. By a mass emergence, the glimmering is watched all at once in each place, The most surprising place of all is the Mine River where We can observe the firefly on a massive scale. And everyone observing it are taken to the world of fantasy. The Luciola lateralis Motschulsky (Jp: Heike-botaru) is observed in each place such as a field, a brook. The Lucidina biplagiata (Jp: Oba-botaru) has few records probably because it is diurnal. The Luciola tsushimana Nakane (Jp: Tsushima-hime-botaru) was discovered by Takehiko Nakane in Sasuna in 1969 and is indigenous to the Tsushima island. Afterwards, Toshiya Uchino confirmed the habitation in the various places in all of the islands. The Akimado-botaru (En: Pyrocoelia rufa E. Olivier) inhabits the habitat of the Luciola tsushimana Nakane (Jp: Tsushima-hime-botaru).

 

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1. Dstribution Condition

The Akimado-botaru is found in Tsushima Island, Jeju, the Korean Peninsula, China (provenance:Ningbo).

It inhabits all over the island. That was reconfirmed in a survey from 1983 to 1984. It mostly inhabits around lowland bush, but it's also confirmed even on a mountain about 400m high. There is an increase in the mountain surface of concrete with the road maintenance and construction in recent years, It has not been seen in that area. Because it's terrestrial, it's not affected by water pollution. The amount of the fireflies has decreased, but there was no great change in the dstribution condition. It is not hard to imagine that the reason for the Akimado-botaru of the continent inhabits in Tsushima would have been as follow: when Tsushima island was part of the Asian Continent, the distribution spread out.

2. Living Circumstances

The biotope of the Akimado-botaru is to be Keeping the suitable temperature and humidity without artificial lights. There are some mossed stone walls suitable for laying eggs, some embankments with the grass, some thickets. The necessary condition is that there are some thickets with the ground shellfish that serve as prey inhabits. The Akimado-botaru inhabits in a thicket, a grassy plain, a field, a graveyard, the grass of the roadside.

Observation spot A

Along a prefectural road running in the valley of Izuhara-machi. A river flows along the road, and thickets grow thick in the roadside, and a humidity retention state is good, and there are the embankment where the grass grew and a mossed gutter. A road and a river form suitable space. There was a huge outbreak of Acusta despecta sieboldianas after rains. In June, a larva is active flourishingly. The firefly flies, too. The Tsushima-hime-botaru grouped in clumps wafts. Females glow lights to wait for males on the bank and the grass in October.

Observation spot B

At graveyard in Izuhara-machi. It is next to a private house across the road, but the light hardly leaks, and it is dark. There is a moss-covered stone wall and mountain in the backround, and is covered in a thicket. Males begin to fly out of the thcket and dance on a graveyard. Females glow lights in the gap of the stone wall.

Observation spot C

A wasteland in Mitsushima-cho. In grassland at the foot of Mountain that weeds grow thickat near the mountain and a river flows. The Acusta despecta sieboldiana inhabits. Because I can relatively look around the wide area, it is a good observation place. About 30 males are observed, looking over the surrounding area.

Observation spot D

It is along a national route 382 in Mine-cho. Along the way, there is the river chosen by the Japanese Pure Streams. The upper reach of the river is near to the source, and mountains approach both sides of it. The Akimado-botaru can be observed in the thicket along the national route. A lot of river fish and marsh snails inhabit in the river. In June, I come to observe larvas of Akimado-botaru, but I would rather have my eyes glued to the mass outbreak of the Genji-botaru (Luciola cruciata Motschulsky).

Observation spot E

It is along a national route in Kamiagata-cho. There is the road and a river in the valley, so it's slightly suitable space. A mountain approaches immediately, and there is a mossed gutter. Weeds grow thick at the edge of the mountain and the river bank. The Tsushima-hime-botaru (Luciola tsushimana Nakane) inhabits, too.

3. Morphology

Individual difference is remarkable, and the length of the imago is larger than other kinds, male 15-22mm, female 20-27mm. The body consists of the head, the chest, the abdomens.

Its head with blackish brown hides under the prothorax and moves freely. The twin developed antennal senses accounts for half of the head. It has big twin compound eyes and complicated trophi.

The chest has 3 segments of a prothorax, a mesothorax, metathorax. Each of them has a pair of limbs. A prothorax has a pair of elytrons, or front wings, and a mesothorax has a pair of hindwings.

The prothorax is one of the characteristics of Akimado-botaru. A backrest is wide, and the center is crimson, and the whole is golden yellow. The leading edge turns over the top, and the back is sculpted points thickly on the dorsal surface, and small granules are in the posterior half. There are transparent parts on front both sides, they are "mado" of so-called window. This is the reason why it is called Akimado-botaru.

The elytron is blackish brown, and it's covered with small hair. It is sculpted points in crinkling pattern of a wrinkle thickly. There are some ridges on it. The elytron which became chitin protects hindwings. The hindwing is dingy and transparent, and it is used for a flight. The female's elytron and the hindwing are degenerate, but a trace of the degeneration is left. The body is larva form and golden yellow.

Both male and female, the abdomen is cogolden yellow, and has the white luminescent organ of two sections. It gives off very bright glow lamp light.

The egg is bigger than the egg of the Genji-botaru (Luciola cruciata Motschulsky) and is about 2mm in diameter. It is flexible and is lemon yellow. The larva is blackish brown in ground beetle-formed, and peripheral edge color is light. It closely resembles a larva of the Ohmado-botaru (Pyrocoelia discicollis).

The pupa does not form the soil cocoon. It is in condition to have curled itself up. The color is a light yellowish-black. (It is deeply beautiful black as wet.)

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image left: Akimado-botaru female(left). male(right) / image center: Eggs of Akimado-botaru / image right: A pupa of Akimado-botaru

 

Kind distribution habitant emergence Luminescence
Luciola cruciata Motschulsky
(Genji-botaru)
indigenous to Japan pure streams from late May to early July slow blinking bright flashes
Luciola lateralis Motschulsky
(Heike-botaru)
Japan. Korea rice fields, farm ponds, streams from late May to early August fast blinking strong flashes
Lucidina biplagiata (Oba-botaru) Japan. Korea woodlands and grasslands on flatland June diurnal, nothing emits light
Luciola tsushimana Nakane (Tsushima-hime-botaru) indigenous to Tsushima woodlands and grasslands on flatland from late May to late July fast blinking strong flashes
Pyrocoelia rufa
E. Olivier
(Akimado-botaru)
Tsushima Island,
the Korean Peninsula, China
thickets on flatland from early September to Mid-October extremely bright glow lamp light

Table 1 Comparison between Akimado-botaru and other kinds (fireflies in Tsushima) 1

Kind average body length characteristic of prothorax and back wing
amount of spawned eggs
remarks
male female male female
Luciola cruciata Motschulsky
(Genji-botaru)
15mm 17mm light red, black cross crest elytron & hindwing 500 feed: Semisulcospira
Luciola lateralis Motschulsky
(Heike-botaru)
9mm 11mm light red, black big vertical stripes elytron & hindwing 80 emergence time is long
Lucidina biplagiata (Oba-botaru) 10mm 11mm blackish brown, both sides red oval crests elytron & hindwing diurnal
Luciola tsushimana Nakane (Tsushima-hime-botaru) 9mm 8mm light red, black thin stain elytron & hindwing hindwing degenerate 60 clumpy mass emergence
Pyrocoelia rufa
E. Olivier
(Akimado-botaru)
18mm 23mm golden yellow, both sides transparents elytron & hindwing both degenerate 55 egg diameter is Twice of the other kinds

Table 2 Comparison between Akimado-botaru and other kinds (fireflies in Tsushima) 2



4. The life cycle

(1) emergence

The emergence time of the male is from the early September to Mid-October, and the late September is the heyday. The record top, the discovery that the male outbreak is the earliest, is August 21. Early September is the average. The emergence time of the female is from the late September to early-mid-October. The discovery that the female outbreak earliest is September 22. The female outbreak is later than the male. This is caused by a length difference and physical structure. It is thought it takes time to grow. The emergence in Korea is from July to September, and from late August to Mid-September is the heyday. The emergence time is influenced by latitude, a weather condition, habitation of the bait. The differenceof of the time is hardly recognized in Tsushima Island.

When it became dark after the sun set, the firefly flies away from the grass while giving off bright glow lamp light of the blue yellow. A ray and a ray again, one after another, flies spirally around about height from 1 to 4m above the ground. It occasionally swoops down on grass and It takes a rest and may not emit light. The moderate temperature of the activity is an average of 18-20 degrees Celsius. When temperature falls, activity slow down. In addition, when It is raining so hard or the strong wind is blowing, it takes shelter from the rain and wind behind the grass at the bright place. The Akimado-botaru hides itself in shade of overgrown grass during the daytime because it is nocturnal. There is not much number of the outbreak at the same place and the same time. Within the sweep of the eye, we can see 1 - 30 males. There is a difference to the number of the outbreak on the year. Weather condition is one of the factor, but it is conceivable that the population of the Acusta despecta sieboldiana which feed it changes on the year.

The female twists a body with luminescent organ upward in a bush, the embankment where the grass grew, a moss-covered stone wall. It wait for a male while glowing fuzzily and more brightly greenish yellow.

The imago consumes only water and oxygen. It finishes the species preservation activity, and it ends its life of the light in about 20 days.


(2) Fertilization - Spawning

A male which discovered a female by her light signal goes down, waving feelers, on grass. The male approaches the female while being attracted to her pheromone, and the male gets behind the female, touching her head. Then the male mounts the female back and they begin to coupulat. They may have affinity. There is the male which does not lead to copulation, plural males often gather around one female. The mating process can take a whole day and night. The sex ratio is unexplained, but the predominantly male ratio is large, The male which did not copulate flies in the middle of October.

The female which finished copulation creeps under the moss, the stone, the dead tree, the weed, and lays 50-60 eggs. The female which finished laying eggs finishes the life in around one week. Both females and males are low in activity after the copulation. The male which did not copulate can live for one month if it is kept in a room and supplied a drop of water. The egg passes that winter, and it hatches in May of the next year and become the larva.


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The life cycle

(3) Larva

The larva lives on ground. It walks around the thicket for bait while stretching out and waving the head with all one's might when it acts. An action is like an inchworm using legs and uropods. The larva also glows light, but the light is weak. Both the emission of light and the action stop when light shines on larva. Because it is nocturnal, it hides itself under the stone,in the base of the grass, at the bottom of the moss in the daytime. If it is kept in the place without a thing hiding itself When a thing hiding itself under, it may act even in the daytime.

The bait are the Acusta despecta sieboldiana (Siebold's globular snail) and the Euhadra herklotsi which are the terrestrial snail. The larva repeats molt as it grows, and passes that winter, and appears on the ground in May in the next year and moves about actively in search of bait. The mature larva spend winter underground for the last molt from late August, and it become a pupa.

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The larva and the Acusta despecta sieboldiana as a bait are fighting. And the result....


 

(4) Acusta despecta sieboldiana

Scientific name is Amorphophallus konjac.Acusta despecta sieboldiana (Pfeiffer,1850), Japanese name is Usukawa-maimai. Acusta despecta is a species of air-breathing land snail, a terrestrial Gastropoda Pulmonata Stylommatophora (fukusokukou youhai-akou hiigan-moku) in the super family Helicoidea (maimai-chouka), family Bradybaenidae (onaji-maimai-ka). It ranges in southern part of Hokkaido down south to Kuyushu island, and southern part of the Korean Peninsula. The habitation places are in the garden of the private house, a thicket and the field without the forest land. It is a grassland insect, so it's comparatively strong against dryness. The husk is thin and round, and the fauces does not turn over even if it grow up. The feature is that there is not streak on the husk. The husk is thin, and the color is from yellow to light dark reddish-brown. The body is transparent, and there appears to be a darkish part or spots inside. The helicocone is suddenly enlarged, and the body whorl is remarkably big. The husk surface shows growth veins clearly, and there is not a color band. The round shell lip is sharp and thinly. The soft body has remarkable variation of the color from a fawn to black by eating habit. An adult shellfish: the shell hight is about 10mm, and the diameter is about 15mm. Adult shellfishes and young shellfishies pass the winter. It's hermaphroditism, the breeding seasons are twice a year, in spring and autumn. It's nocturnal, but it is active even in the daytime on a cloudy and a rainy day. It's a pest which eats away vegetables before a person notices for the farmer. There is much damage in cultivated field with a lot of organic matter and high humidity. So there is a need to improve the environment. Because it becomes the bait which a larva of Akimado-botaru always eats in Tsushima, there is little damage, but I'm in a complicated state of mind. Rather, fantastic light of Akimado-botaru takes priority in the relation with the person.

(5) Pupa

The pupa does not make the soil cocoon like a Genji-botaru, and it does not move by curling up under the soft ground such as moss, a stone, a bottom of the grass. It occasionally emits a moderate yellow-green light.

(6) Luminescence

There is the species which does not glow light like Oba-botaru, but people is charmed by the light of the firefly.

The luminescence of the firefly, the brightness, the luminescence pattern differ according to the kind, but it has the people feel the elegance, and it gives the viewer comfort. The Genji-botaru firefly is relatively bright light, and it's loved deeply by Japanese from the days of Hikaru Genji. The simultaneous group luminescence is occaionally observed. The boisterous dance of the light which spreads all over the river, the sight has been indelibly etched in my mind. The Tsushima-hime-botaru glows, sometimes flash light, in the thick grass early in the evening, but around 20:00 it flies about forest and bush, glowing strong golden light, blinking more often. It rarely forms a group, but it's aggregate unlike other fireflies. An elliptic lump of 4m in height drifts in the small space on the road flashing golden light rapidly.

In the case of a mating action, the luminescence of the firefly is used for the communication with the friend. The difference of luminescence pattern is for the identification of the friend.

By the way, about the real nature of the luninescence. The luminescent organ is made of the luminous body consisting of luminescent cells, a reflector, the transparent panniculus on the surface of luminous body. light production in fireflies is due to a type of chemical reaction called bioluminescence. The enzyme luciferase acts on the luciferin, in the presence of magnesium ions, and oxygen to produce light.

The luminescence of the Akimado-botaru is glow lamp light having few glimmering. (John Edward Lloyd said...) The firefly glowing serially like Akimado-botaru does not relate the information to certify the species because the communication in case of the mating action is extremely simple. However, because the Akimado-botaru in autumn is different from other fireflies in a season of the emergence, in fact that may not be necessary.

The light of the Akimado-botaru is the brightest in the Japanese firefly. If dozens of them are collected, the historical fact of Sha In (Che Yin : a politician of old West Jindynasty of China), the story that he studied by the glow of a firefly because he could not buy kerosene, is not exactly an exaggeration.

It is usually rare that the Akimado-botaru forms groups, but we may watch several thousand groups at a grassy plain once in a while. This gregariousness is also watched to other kind of firefly. This is considered to be the action for mating or competing for a female, but the whole aspect is unknown.

 

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The foreign enemy of Akimado-botaru is a mantis, a spider, fungi. Although this is providence of the natural world, the firefly is destroyed when a human being affects the firefly. Today the situation is such that the number of Akimado-botaru has decreased. It is urgently necessary to take a protective measure before stigmatizing as biological extinction. The luminescence of the firefly invites a person watching it to the world of the fantasy. We would like to be content to just watch.

The factor to destroy the Akimado-botaru may depend on the interaction of artificial factors, such as abnormal weather, a natural factor of the lack of bait, a weed killer, pollution of the verminicide air dispersion, a roadwork, the artificial illumination. Improving our living environment is opposite to the deterioration of the habitat environment, but it should be sought to follow a path of coexistence. Fortunately, Tsushima has been developed, but the Akimado-botaru has not been exterminated because the nature has been protected in this island. It's fortunate to be conservation of Species because the Akimado-botaru is terrestrial.

The artificial breeding is one of the cnservation measures, but rearing environment control is difficult, and The Akimado-botaru produces few eggs, about one tenth of the Genji-botaru, So we cannot expect much of it. Because environment changes with those days when the Akimado-botaru was designated as a special natural treasure, it is necessary to enlarge a designation area. The designated area need to be expanded.

 

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At first, Mr.Watase investigated the Akimado-botaru and announced it, then Mr.Matsumura introduced it together with the Mado-botaru later. After that, it was designated as a special natural treasure by Nagasaki Prefecture in 1966 and it became known to the hometown Tsushima. NHK broadcastsed "Akimado-botaru" in 1973, and it became well known. Mr.Ohba investigated it in Tsushima in 1980, and announced the habits. In the meantime, Mr.Urata continued research activities in his hometown. The Akimado-botaru also appears in numerous literary works.

In the novel "Autumn of the island" written by Genjiro Yoshida, he says "The Milky Way was full of refreshing atmosphere. Tens of thousands,innumerable fire for luring fish fill Genkai-sea at night, and were flickering. A big mountain firefly has flown across the path and disappeared." Genjiro has experienced the autumn in Tshishima island in 1907 and 1908. We can imagine easily that he mountain path in the novel is Sasu Pass because of its contents. "A big mountain firefly" is the Akimado-botaru judging from the fireflies of five kinds in Tsushima. The author may be greatly impressed by the firefly flying in autumn in Tsushima. By the way, the Akimado-botaru has been confirmed the habitation in the vicinity of Sasu Pass.

It's very interesting, from the viewpoint of diffusion and distribution, that the Akimado-botaru inhabits only in Tsushima in Japan. Though a part of the ecology has been elucidated, many subjects still remain such as wintering habit, gregariousness.

The firefly is one of the most telling barometer of the nature. To decrease in the firefly means that to deteriotate our living environment. We promte the conservation activities including other species, and we would like to take over those fantastic lights and hand them down to posterity.

 

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- Toshiya Uchino (1981) "The Akimado-botaru" . "Nagasaki prefecture Education and Research"
- Kiyoshi Tanaka & Toshiya Uchino (1989) "Fireflis in Nagasaki prefecture" . "Living Things in Nagasaki prefecture"
- Toshiya Uchino (1996) "The firefly in Tsushima" . "Nature and Culture in Tsushima"
- Nobuyolshi Ohba (1980) "Akimado-botaru in Tsushima". "official library bulletin of Yokosuka City Museum"
- Nobuyolshi Ohba (1988)"Genji-botaru"
- Kim Shoukan & Nam Sougou (1981) "Survey Report of the Korean Firrefly (Korea University)"

 

Essay "Be charmed by the firefly in autumn"

 

 

 Nanja Monja Land top page WB01343_1.gif (599 バイト) "The firefly in Tsushima"

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