Japan tackles invasive fire ants in first colony found this year, in China shipment

“There is no question that this is becoming a bigger problem every year,” said Dr Koichi Goka, head of the Invasive Species Research Team at the National Institute of Environmental Studies.

“The first fire ants were found in a cargo in 2017 and since then, virtually every month another colony is discovered at a port somewhere in Japan,” he said.

To date, there have been 110 cases reported to the authorities, he said, “but we have been fortunate to find them and quickly eradicate these colonies”.

A queen fire ant can produce as many as 1,600 eggs a day and the insects, which have a reputation for being aggressive, can grow up to 6mm long. Authorities in other countries have confirmed that their bite can cause anaphylactic shock and, in extreme cases, have been reported to have caused death in very young or elderly people.

There have been no reports of colonies beyond the immediate environs of ports, Goka said, but officials and port staff have been instructed to remain alert.

Scientists at the institute have developed a new insecticide to spray inside containers that is now available at every port in Japan. They have also created a bait that contains pesticide.

The ants could cause a great deal of damage if a breeding colony entered a city environment.

“Most of Japan is too cold in the winter months for these ants, so we expect that they would try to nest in urban areas, taking advantage of the ‘heat islands’ created by homes and other buildings,” Goka said.

“They could thrive in that sort of environment, causing damage to structures and injuring people.”

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And if the larger and more aggressive insects entered the subtropical areas of southern Japan, such as Okinawa