Maize weevil
© Provided by Hiroki Obata
Traces of a maize weevil on earthenware.
Maize weevils found in potsherds from the Jomon Pottery Culture (c. 8000 B.C.-300 B.C.) period point to an ancient belief that the bug is the incarnation of chestnuts and thus a harbinger of a good harvest, a researcher said.

That hypothesis was presented by Hiroki Obata, a professor of archaeology at Kumamoto University, who previously found that weevils, known as a pest that attacks crops like rice, wheat and maize, feasted on stored chestnuts before grain cultivation had fully started.

Obata discovered that an estimated 500 or so maize weevils had been apparently deliberately mixed into clay for earthenware from the late Jomon period found at the Tatesaki archaeological site in Fukushima, Hokkaido.

Obata, who has extensively researched insect and plant impressions left on Jomon pottery, used X-ray CT scanning and other methods to examine the outer surfaces and insides of the fragments.

The results were presented in an article published by the British academic magazine Journal of Archaeological Science Reports in November.

Obata concluded that Jomon people intentionally mixed maize weevils into clay when crafting the earthenware. He said the number was too large for the insects to have been mixed in accidentally.

The research article does not discuss the meaning of hundreds of maize weevil remains contained in the vessel.

However, Obata said: "Our findings may indicate that Jomon people regarded maize weevils as the incarnation of chestnuts and used them to pray for good (chestnut) harvests. I think the discovery gives a glimpse into some of their way of thinking."

Maize weevils are primarily known for the damage they cause to rice. Past studies by Obata and others revealed that the ancient species ate acorns, chestnuts and other kinds of nuts stored in warehouses during the Jomon period, long before rice cultivation fully took off.