A research team from Nara Women's University and the Osaka City Museum of Natural History, with the cooperation of the Sakurai City Makimuku Studies Research Center, has discovered the world's largest collection of earthen pits from the Kofun period excavated from the Makimuku Ruins in Sakurai City, Nara Prefecture. I found a piece of an old German cockroach.
The earthen pit discovered during the survey of the Makimuki ruins dates from the first half of the Early Kofun period (late 3rd century, Furu 0-type period).As a result of collecting soil from this earthen pit for each layer and performing flotation and washing with water, fragments of the German cockroach were discovered among the many animal and plant remains detected.It was identified as a German cockroach based on the pattern on its pronotum.
German cockroaches have long been thought to be native to northeastern Africa, and were thought to have crossed over to Europe from the Mediterranean Sea on ships.It arrived in Britain in the mid-19th century (during the Crimean War), and then migrated to North America, where it breeds in large numbers and is distributed as far north as Alaska, with the first record in Australia in 1893.There is a description that suggests that it came to Japan around the end of the Edo period as a result of trade.
The research team believes that German cockroaches have been present on the Japanese archipelago since the Kofun period.The reason is that all the hair on the surface has fallen out and no modern hair has mixed in.In addition, a literature review conducted after this discovery revealed that the cockroach discovered in the soil layer of the Ikegami-Sone ruins (Osaka Prefecture), believed to date from the mid-late Kofun period (late 5th century), was actually the German cockroach.
In recent years, it has been suggested that the German cockroach originated in Asia.There is a theory that the Okinawa teal cockroach, which lives outdoors and is distributed from Okinawa to Southeast Asia, originated in Asia, and that the black cockroach, which is believed to be native to southern China, originated in Japan.The research team points out that both may have originated in Japan.
