Professor Hiroki Obata of the Faculty of Letters, Kumamoto University and others discovered the remains of cockroach eggs from the Jomon period at the Motobaru site in Miyazaki City.It is the first example of excavation from the Jomon archaeological site, and is expected to be a clue to research on the origin and transmission of Japanese cockroaches.
While investigating the traces of the maize weevil excavated from the site, the research group discovered two traces of eggs called cockroach eggshell indentations.By the molding method using silicone rubber for the pottery, one point each was detected from the pottery pieces of the early Jomon period about 2 years ago and the early leaves of the same period about 4300 years ago. The two points were considered to be highly similar to the eggshells of Smokybrown cockroaches by comparison with the eggshells of various cockroaches.The time when cockroaches arrived in Japan and the actual state of their evolution indoors after that were estimated only by literature because there were few cases of excavation from archaeological sites, and many were unknown.Smokybrown cockroaches have been said to have originated in southern China and spread to Japan during the Edo period.However, due to the excavation from the Jomon site this time, it is possible that it came from the continent before 4000 or is a native species of Japan.
At the Honnohara site, a huge number of remains and ruins from the late Jomon period have been discovered, and the buildings and residences are also the largest in western Japan.It was estimated that the settlement was extremely habitable based on the large number of earthenware and the largest number of indentations on the maize weevil in Japan, and the detection of indentations on the eggshell of cockroaches supports this.
This discovery raises new issues in research on the origin and transmission of cockroach in Japan, and at the same time, it is thought to be a reference for elucidating the lifestyle and living environment at that time.
