Poisonous Australian spiders creeping closer

NAGOYA--A team of exterminators lifted metal grates off ditches at an industrial complex in Minato Ward and stared at the poisonous female redback spiders crouched on their webs glaring back at them.

Working quickly, the bug busters sprayed the nest of dangerous arachnids with insecticide.

Redbacks, which are native to Australia, inject a neurotoxic venom that can cause severe pain and even death.

Local government officials fear the spiders are now firmly established at Nagoya and Yokkaichi ports and surrounding areas, presumably after having hitched rides on ship cargoes.

Worse yet, the eight-legged invaders are on the move, closing in on residential districts, officials say.

In Osaka Prefecture, a 6-year-old boy was treated with antivenom in June, the first time the antivenom was administered in the country after a redback spider bite.

But central and local governments have been slow to thwart the proliferation of redbacks.

A female redback has a round body about 1 center long, while males are smaller, measuring 3-5 millimeters.

According to Mutsuo Kobayashi, head of the entomology department at the National Institute of Infectious Diseases, the spiders produce a neurotoxin, called alpha-latrotoxin, which acts directly on the tissues of the central nervous system.

Severe pain and sweating as well as nausea and other symptoms follow after a bite from a redback.

Antivenom is widely available in Australia, where it was developed after bites from the spider resulted in deaths.

However, it has not been officially approved for use in Japan.

Only a handful of hospitals, including Mie Prefectural General Medical Center in Mie Prefecture and Osaka General Medical Center in Osaka Prefecture, stock redback spider antivenom.

The presence of redbacks in Japan was confirmed in Osaka in 1995.

The Osaka prefectural government has so far received 12 reports of redback spider bites this year.

In many cases, residents were bitten while cleaning their yards or were bitten by spiders lurking in slippers left outdoors.

According to the Environment Ministry's Office for Alien Species Management, through September, redback spiders had been sighted in 16 of 47 prefectures, primarily in western Japan. The ministry's figures were based on media reports.

The poisonous arachnid was found in several locations in the Tokai region, including Kiso Sansen Park straddling Aichi, Mie and Gifu prefectures, Central Japan International Airport and Nagoya Port's Kinjo pier.

However, it is difficult to get a precise handle on the extent of their proliferation.

The Aichi prefectural government and the Nagoya municipal government carry updated spider counts and locations where they were spotted on their websites, but the information is limited to reports submitted by local public health officials.

"Companies and individuals are not required to report to us, so we do not have a precise picture of how far they have spread," said an Aichi prefectural government official.

No redback bites have been reported in the three prefectures.

In the industrial complex in Minato Ward, redback spiders were first spotted last year when workers inspected outdoor equipment.

Yukio Watanabe, an employee of Sanseisha Co., the firm hired to exterminate the spiders, said he fears the species is here to stay.

"I suppose that they infiltrated the industrial complex by sneaking into tanker trucks that come and go in the area," Watanabe said. "The spiders will settle here as long as there are ditches to live in and enough landscaping to provide insects they can prey on."

Takesada Ohashi, managing director of Aichi Prefecture Pest Control Association, a group of companies tasked with stamping out the pest, said redbacks had settled in areas along Route 23 and 247, which run along Ise Bay.

"In Mie Prefecture, they were sighted in residential areas in Kuwana city. I am concerned that children, curious about their striking appearance, may try to touch them," Ohashi said.

Redback spiders have a red stripe on their abdomen.

While the central government and other authorities are supposed to eradicate the redbacks--designated an invasive alien species by law--it is not clear which government agency or ministry should take point.

Bureaucrats in Tokyo pushed the problem down the food chain.

"The central government entrusts local governments to handle the problem of redback spiders," said an official at Environment Ministry's Office for Alien Species Management.

However, officials at the Aichi prefectural government said responsibility lies with private-sector landowners and property managers. Local governments, they said, are responsible only for public spaces, such as parks.

Trying to untangle this bureaucratic web is tricky.

The Ministry of Health, Labor and Welfare seems to be off the hook. Legally at least, the task of getting rid of the deadly spiders does not fall under its jurisdiction.

An official at the ministry's Health Services Bureau admitted that the ministry had provided no help or guidance to public health centers across the country about the problem.

Masahiro Yoshida, a former senior researcher at the Osaka Prefectural Institute of Public Health, has studied the species for many years. He said orchestrated efforts by local governments and residents are needed to stamp out the hazardous creatures.

"Local governments and community associations could regularly clean ditches along roadsides. That alone would help a lot. Government ministries and agencies should join forces immediately to tackle the problem," Yoshida said.

He continued: "If no steps are taken, people could die from bites. The spiders are spreading all over the country like wildfire via distribution routes."

According to the National Institute of Infectious Diseases, people should wear gloves when stamping out redbacks, and kill them by stepping on them or by spraying them with household insecticides.

Redback eggs should be placed in a plastic bag and burned. Spraying the eggs with insecticide can be ineffective.

If bitten, try to kill the spider and take it with you to the hospital so medical personnel can immediately determine the correct treatment.(IHT/Asahi: November 24,2009)