''Nipponoluciola cruciata'', known as "genji-botaru" (ゲンジボタル) in Japanese, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of firefly found in Japan. Its habitat is small ditches and streams, and its larvae are aquatic. It was formerly known as ''Luciola cruciata'' but was revised taxonomically in 2022.

Taxonomy

This species was described by

Victor Motschulsky Victor Ivanovich Motschulsky (sometimes Victor von Motschulsky, russian: link=no, Виктор Иванович Мочульский, 11 April 1810, in St. Petersburg – 5 June 1871, in Simferopol) was a Russian entomologist mainly interested i ...

in 1854. The type locality is Japan, but it was incorrectly given as Java. Its Japanese name, "genji-botaru", may derive from '' The Tale of Genji'', an 11th-century Japanese novel, or it may derive from the

Genji clan was one of the surnames bestowed by the Emperors of Japan upon members of the imperial family who were excluded from the line of succession and demoted into the ranks of the nobility from 1192 to 1333. The practice was most prevalent during the ...

, which won the 12th-century Genpei War. (Another, smaller firefly species, '' Aquatica lateralis'', has the Japanese common name "heike-botaru", a possible reference to the

Heike clan The Taira was one of the four most important clans that dominated Japanese politics during the Heian, Kamakura and Muromachi Periods of Japanese history – the others being the Fujiwara, the Tachibana, and the Minamoto. The clan is divided ...

, the losers in the Genpei War).

Description

The male is long and wide. The female is larger, long and wide. The

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum ( dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

is reddish pink, with a central marking. The black

elytra An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

are elongate. In the male, the venter is brown and pale yellow, and in the female, it is brown, yellow and reddish pink. The male's luminous organ occupies its sixth ventrite. The antennae, about long, are between the eyes, which are well developed. The larva's body is soft, with gills. It has defensive organs that are eversible (can be turned inside out).

Distribution and habitat

This species occurs throughout Japan, except

Hokkaido is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The lar ...

and

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

. There is one unconfirmed record from Korea. Its habitat is small ditches and streams, with mud or pebbles at the bottom. Adults are found from May to July.

Behaviour and ecology

Larvae of ''Nipponoluciola cruciata'' are aquatic; unable to swim, they crawl at the bottom. They prey on ''

Semisulcospira libertina ''Semisulcospira libertina'' is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Semisulcospiridae. Widespread in east Asia, it lives in China, Taiwan, Korea, Japan, and the Philippines. In some count ...

'' snails. Moriya S., Yamauchi T. & Nakagoshi N. (2010). "Sex ratios in the Japanese firefly, ''Luciola cruciata'' (Coleoptera: Lampyridae) at emergence". '' Japanese Journal of Limnology'' 69(3): 255–258. . They have six to seven

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

s. The fireflies emerge from underground pupae around June. Maturity is reached in more than one year. Adults live for less than three weeks, and they do not eat anything. Their flash communication system is known as the "complex system". The flying males flash synchronously; the females do not fly while flashing, and their flashes are not synchronized. The male's flash pattern changes when it perches near a female, which emits single pulses. The male then approaches the female, and they copulate. In western Japan, there are two seconds between the male's flashes, and in northern Japan, there are four seconds. Intervals of three seconds occur between these two populations. The female lays 500–1000 eggs. In western Japan, females lay eggs in groups, but they are solitary in eastern Japan.

References

External links

{{Taxonbar, from=Q2258699 Lampyridae Bioluminescent insects Insects of Japan Beetles described in 1854 Aquatic insects