[First Record on Yakushima Island] A Rare and Mythical Insect? Discovery Record of the Tenryu Medaka Dwarf Water Beetle (Published in "Monthly Insects")

This article contains a draft of the report titled "A Record of the Tenryu Medaka Chibikawa Ground Beetle in Yakushima," which was published in the following journal.

Citation method: Ikeda, K., & Watanabe, T. 2019. A record of Asaphidion tenryuense konoi S. Uéno, 1955 in Yakushima. Gekkan Mushi 586: 41-42. [Ikeda, K., & Watanabe, T. 2019. A record of Asaphidion tenryuense konoi S. Uéno, 1955 in Yakushima] ISSN: 0388-418X

This article was written assuming the first record of the *Tenryu medaka* subspecies of *Tokara* on Yakushima Island.

There may be minor changes in wording, but the cited references remain the same. For more accurate information, please refer to the journal.

The following page provides supplementary information for this article.

I've discovered additional literature records of the Tenryu medaka small river ground beetle!Ecological Notes(Published paper)

This article contains the full text of "Literature Record of Tenryu Medaka Chibikawa Ground Beetle, Adding to Ikeda and Watanabe (2019)," which was published in the following journal. For those wishing to purchase the print or PDF version, please use the link below. Any errors in identification or information will be corrected in subsequent issues…

ecological-information.com

Distribution of the Tokara subspecies of the Tenryu medaka (a type of medaka).

Asaphidion tenryuense Habu, 1954 is a species found from Honshu to Kyushu and is known as a rare species (Nakane, 1978). Among them, the Tokara subspecies Asaphidion tenryuense konoi Ueno, 1955 has been considered a subspecies of Nakanoshima in the Tokara Islands, Kagoshima Prefecture (Nakane, 1978), but in recent years, individuals thought to be of the same subspecies have been recorded on Tokunoshima (Hirano, 2008) and Satsumasendai City (Hirano, 2008; Aozaki, 2011), and its habitats include the base of Miscanthus grasslands, riverbanks and fields, and the bark and cracks of oak trees in mountains and elementary schools (Hirano, 2008; Aozaki, 2011).

The author's record of Yakushima

The authors photographed a Tenryu medaka dwarf ground beetle (Asaphidion spp.) near the Yakushima World Heritage Center in Anbo, Yakushima Town, around 1:30 PM on November 29, 2017, and report the findings here. Its protruding compound eyes, fine hairs on the dorsal surface, and inconspicuous striations clearly indicate it belongs to the genus Asaphidion. This species is distinguished from the related Asaphidion semilucidum (Motschulsky, 1861) by the absence of bristles on the posterior corners. The Tokara subspecies of this species is distinguished from the nominate subspecies by a clearly protruding central posterior margin of the prothorax and the presence of only the first and second striations on the elytra (Nakane, 1978). This individual lacks bristles on the posterior corners, and while the elytral striations are difficult to discern, the protrusion on the central posterior margin of the prothorax suggests it is the Tokara subspecies. The filming location is at an altitude of approximately 28m, surrounded by a cedar forest, with stairs and a parking lot nearby. The ground surface outside the developed area is covered with numerous mosses, and fallen cedar trees can also be seen. This subspecies was observed wandering on the moss. This report may fill the gap between the distribution reported for Nakanoshima and Satsumasendai City, and its habitat differs from previously reported examples.

References

Aozaki, Yukio, 2011. Collection of *Tenryu medaka dwarf ground beetle* in Satsumasendai City. SATSUMA 146: 249-250.

Nakane, Takehiko, 1978. Beetles of Japan (51). Insects and Nature 13(8): 4-10.

Hirano, Yukihiko, 2008. New locality and habitat of the Tokara subspecies of *Tenryu medaka dwarf ground beetle*. *Gekkan Mushi* (Monthly Insect Magazine) 454: 31-32.