Preventing invasion of venomous fire ants First detected in Japan this spring -毒蟻日本で初めて発見-


Fire ants, a poisonous species native of South America, have been discovered one after another across Japan, mainly in coastal areas, since late in May, causing grave concern among local residents. Once bitten by the insect, humans suffer a severe burning sensation and may die in extreme cases. While they have already been found in Australia, Taiwan, Southern China and some other Pacific Rim countries, their existence was confirmed for the first time in Japan. The Ministry of the Environment has been warning people to be on the alert. Is it possible to block their further invasion into Japan? And what precautions are being taken?

According to the National Institute for Environmental Studies, fire ants vary in size from 2.5 to 6 mm, have a red brown body and darker abdomen, and build a nest (anthill) 15 to 50 cm tall on the ground. They are fierce and aggressive by nature, stinging humans over and over again. Their fertility is proved to be quite strong, with each queen producing up to 2,000 to 3,000 eggs per day.

Japan’s Invasive Alien Species Act designates fire ants as a specific creature that disrupts the ecosystem and causes damage to agricultural, forestry and fishery industries as well as human life and health. Once a creature is so specified by the act, its feeding, cultivation, storage, transfer and import are placed under severe restrictions. Furthermore, the legislation requires the state and local governments to take preventive measures where necessary. Accordingly, effective countermeasures need to be urgently taken to prevent the insect from settling in Japan.

On July 4 when a swarm of fire ants were found at Osaka-Minami Port, then Environment Minister Koichi Yamamoto said at a press conference, “The government will do all it can to detect and exterminate (them) as early as possible,” stressing a policy to push ahead with what he called a shoreline operation across the country. In Kobe where fire ants were also detected on July 13, Mayor Kizo Hisamoto told his regular press briefing, “We will step up our fight against harmful alien species centering on insets by enlisting knowledge and information from experts.” The city has formed a task force, made up of Koichi Goka, head of the Ecological Risk Assessment and Control Section of the Center for Environmental Biology and Ecosystem Studies at the National Institute for Environmental Studies, and about 10 other members including specialists and Environment Ministry staffers, with a view to working out a basic plan geared for prevention at an early stage of the invasion by harmful alien species.

Then, what have other countries done so far to counter the invasion by fire ants? On July 10, the Asahi Shimbun reported a successful case in New Zealand where fire ants were found in 2004 and 2006. It said that periodical checks in the port areas and citizens’ constant supply of relevant information resulted in an early detection of the insects, making New Zealand the sole country to exterminate them. Will Japan be able to keep quick-breeding fire ants at bay?

(Written by: Yuto Yawata)






(八幡 侑斗)

photo credit: 東京都環境局ホームページ


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