TOKYO -- The Environment Ministry has begun to take countermeasures against invasive red imported fire ants at 68 ports and harbors around the country, following the first discovery of the ants in Japan in May 2017.

The Environment Ministry believes that now is a crucial time to prevent fire ants from settling in Japan and breeding after they first appeared last year.

The ministry will investigate the spread of the ants before the hot and humid summer, an ideal environment for the ants. Ministry officials have also given lectures for local governments in a bid to help them prevent an invasion of the ants.

It is believed that more than half of the fire ants found in Japan last year entered the country in shipping containers imported from southern China. The Environment Ministry asked Chinese authorities to set up poisonous ant traps inside shipping containers before vessels leave its ports. However, the Chinese authorities apparently didn't respond.

An Environment Ministry official commented, "We will continue to monitor the fire ants in cooperation with relevant Japanese organizations."

Invasive fire ants were first found inside a container delivered from Nansha Port in China to Amagasaki, Hyogo Prefecture, in May 2017. Following the discovery, a probe confirmed more than 6,500 fire ants in 12 prefectures, including the ants on the premises of container yards. Local officials consequently exterminated the ants.

According to the ministry, the ants apparently haven't settled in Japan even though partially formed ant colonies were found.

Red imported fire ants are an alien species and may cause severe allergic reactions.

Part-time lecturer at the University of Tokyo Mamoru Terayama said that there was a successful case of eradicating fire ants in New Zealand in the 2000s in the early stages after their invasion. On the other hand, the United States, which failed to eradicate the ants, suffered annual financial losses from the ants between roughly 600 to 700 billion yen due to extermination and medical expenses.

(Japanese original by Kazuhiro Igarashi, Science & Environment News Department)