EDITORIAL: Joint efforts in Japan needed to fight off invasion of red fire ants

Swarms of red fire ants, a venomous invasive species of ant, have been found at a pier at Tokyo Port.

An investigation by the Environment Ministry and the Tokyo metropolitan government has found colonies with more than 50 queens. It is possible that Solenopsis invicta has already spread from Tokyo Port to other parts of the nation.

The fresh discovery of the ferocious little arthropod known as “hiari” in Japan should be taken as a sign that the battle to prevent large-scale infections is now at a critical juncture. The public and private sectors need to work closely together in determined campaigns to eradicate the species.

Fire ants, a native of tropical and subtropical South America, first invaded the United States in the 1930s, and have spread to other parts of the world in this century, including Australia, China and Taiwan.

In Japan, the fire ant was first discovered two years ago in a port in Hyogo Prefecture. Several other discoveries of fire ants have been reported in the nation since then. But the discovery at the Tokyo pier involved by far the largest number of queens.

There is no dearth of introduced species that have become established in Japan. But fire ants could cause far greater economic and ecological damage.

Cases in other countries show that failing to take effective measures to prevent widespread infections will cause the cost of dealing with the pest to soar.

In the United States, the economic losses caused by the ant, which invades houses and parks and damages telecommunications facilities and electrical products as well as crops and livestock, have been estimated to be 700 billion yen ($6.42 billion) annually.

Australia has spent some 30 billion yen to prevent the ant’s spread.

The other day, the government held the first meeting of ministers concerned in two years and decided to make all-out efforts to eradicate the ant at the Aomi container terminal, where the colonies of multiple queens have been found.

In addition to carrying out an investigation and a campaign to exterminate the ant in areas within its usual 2-kilometer range of activity from the colonies, similar steps will also be taken beyond the scope in parks and roadside areas where fire ants tend to establish their colonies.

To ensure the effectiveness of the measures, the government needs to seek close cooperation from port authorities and businesses handling containers.

The Aomi terminal is close to Odaiba, a popular tourist spot on a man-made island in Tokyo Bay bustling with commercial facilities and condominiums.

The awareness of the serious risks posed by the ant should be shared with the operators of such facilities and local residents. The success of the anti-hiari campaign depends on effective efforts to ensure that local businesses and residents will help by supporting measures to discover and stamp out the ant and reporting to the authorities when they find ants that look like fire ants.

It is also vital to provide accurate information about the problem to the public. The fire ant’s bite or sting causes strong pain but seldom is life-threatening unless it elicits an acute allergic reaction in the victim, such as difficulty in breathing.

The efforts to kill fire ants with chemical pesticides, however, could backfire by wiping out the ant’s natural enemies, principally other ant species, thus making it easier for the fire ant to spread.

As it gets colder, the fire ant will become less active. But that does not warrant any optimism.

Since fire ants are expected to survive the winter in Japan, surveillance and preventive efforts should be planned and executed for several years.

The central and local governments need to secure necessary human and financial resources to tackle the challenge.

In New Zealand, where fire ant colonies were first discovered in 2006, three years of strict measures to control the spread of infestations, such as restricting movements of soil and plants within the 2-kilometer radius from the colonies, proved successful in thwarting the ant’s efforts to become established.

If more colonies are found in Japan, the government should consider similar strong actions to deal with the pest.

--The Asahi Shimbun, Oct. 28