Asian tiger mosquitoes reach California in plant shipments

By Leon Drouin Keith

Associated Press Writer

LOS ANGELES (AP) --

Tiger mosquitoes, known as disease carriers in their Asian homeland, have been introduced into Southern California through shipments of "lucky bamboo," an increasingly common sight in garden nurseries, swap meets and chain stores.

There have been no documented cases of disease in the United States transmitted by the mosquitoes. However, in Asia they have been known to carry viruses that can cause serious infections.

"It's not a danger now, but the possibility is there," said Mike Shaw, director of operations for the Greater Los Angeles County Vector Control District. "This is probably one of the biggest transmitters of diseases out there."

So far, the insect has been found only in maritime shipments to Los Angeles. But ports in San Francisco, Seattle, New York and New Jersey also receive shipments of lucky bamboo, which comes packed in water where mosquitoes can breed.

Lucky bamboo from those shipments is sent all over the country.

Lucky bamboo, or dracaena sanderana, is not part of the bamboo family but resembles the fast-growing plant.

It's a symbol of good luck in Asia and has grown popular in the United States. Some practitioners of feng shui -- the Chinese art of arranging one's environment to enhance positive forces -- use lucky bamboo in designing living spaces.

"Within the last year or so it just took off," said Tony Yung, co-owner of 99 International, a Los Angeles-based company that imports lucky bamboo, mostly for florists. "It's beautiful; it's better than playing with soil all day long. It just grows in the water."

Producers had shipped lucky bamboo via air until about a year and a half ago. Its growing popularity led some distributors to increase volume and reduce costs by using maritime shippers. But switching to sea deliveries meant the bamboo must be stored in about 2 inches of water for about two weeks in cargo containers.

"These maritime containers are temperature controlled, which makes them the perfect breeding ground for mosquitoes," said Mir Mulla, a mosquito researcher at the University of California, Riverside.

Pest control officials were alerted to the problem last week, when mosquitoes flew out of a shipment from South China as agricultural inspectors opened it in the Port of Los Angeles.

On Tuesday, researchers with the Centers for Disease Control and Prevention identified the insects as tiger mosquitoes, which had not been seen before on the West Coast.

The mosquitos also have been found at a greenhouse that distributes lucky bamboo, Shaw said.

It's unclear how far the mosquitoes might have spread. The district is still in the process of checking for tiger mosquitoes around the greenhouse and at four others that deal in imported lucky bamboo.

Crews are spraying pesticide into every individual container of bamboo shipped into Los Angeles. However, Shaw said long-term solutions must come from places where the shipments originate, including China, Thailand and Malaysia.

"We can't continue to do it like this," said Shaw, who sprayed 1,000 containers himself at one greenhouse.

Yung said most of his company's shipments are sent by air but some are sent by ocean freight. He said shippers ought to use pesticides before the lucky bamboo begins its ocean journey.

"If they fog it before they ship it, it shouldn't be a problem," Yung said.

-- PHO (owennos@bigfoot.com), June 29, 2001

Answers

MORE:Mosquito That Can Carry Dengue Fever Lands in L.A.

By APARNA SURENDRAN, STEVE HARVEY, Times Staff Writer

Health authorities say several Asian "tiger mosquitoes," a species known to cause dengue fever and encephalitis in Asia, have been found in Los Angeles Harbor and at a wholesale nursery.

The mosquitoes were discovered at the harbor two weeks ago in small containers of "lucky bamboo," an ornamental plant regarded by many Asians as a good luck charm. The containers held two to three inches of water, which facilitate mosquito breeding.

"We have taken immediate measures to control the problem," said Arthur Tilzer, who heads the Consumer Protection Bureau of the Los Angeles County Department of Health Services. All newly shipped containers of lucky bamboo will be held at port and inspected, officials said; if any mosquitoes or larvae are found, they are to be destroyed.

Dr. Jonathan Fielding, health officer for Los Angeles County, said the mosquito, which has existed east of the Mississippi River since the 1970s, has never been known to cause human illness in the United States. But this is the first time it has been found on the West Coast.

He said people can protect themselves from mosquito bites with repellents containing the chemical DEET. Minoo Madon, technical director at the Greater Los Angeles County Vector Control District, recommended emptying out any containers with stagnant water and cleaning out rain gutters.

Dengue is a viral disease that can cause headaches, joint and muscular pain, and rashes. The Asian tiger mosquito also can carry encephalitis.

-- PHO (owennos@bigfoot.com), June 29, 2001.

Not sure about this but...

What is the life span of said mosquito ? Do they have a 2 week life span to make it thru the ocean voyage? How long do the viral nasties live in the gut of a mosquito ?

If life span of mosquito < 2 weeks then those hatching would be 'clean' - right ?

If life span of virus < 2 weeks then no disease would survive the trip - right ?

Anyone else see this angle ?

J

-- j (jw_hsv@yahoo.com), June 29, 2001.

Good question about the lifespan.

But does the disease get transfered to the young?

This just shows how easy it is to get nasty bugs into the US [pun intended]. The inspectors are not staffed well enough to cope with the volumes.

-- (perry@ofuzzy1.com), June 29, 2001.

The mosquitoes survive the ship voyage as eggs, which hatch into larvae, which must live in water. Yes, they emerge "clean", since they don't bite as larvae. But they soon bite a diseased host, and then can transmit disease with the next bite.

The main mitigating factor in this ominous threat is the fact that the larvae require stagnant water. And it seldom rains in coastal Southern California in summer. Hence, available stagnant water can be made scarce, as part of the eradication effort. If successful, the mosquitoes cannot reproduce.

-- Robert Riggs (rxr.999@worldnet.att.net), June 30, 2001.

June 28 — A new mosquito carrying potentially fatal diseases has made it all the way to Southern California from Asia.

The tiger mosquito, originally from southern China, is striped like its namesake. And while tiny as an insect, it could be as fearsome as any wild feline: the tiger mosquito may carry diseases such as dengue fever and encephalitis, both of which can be deadly. "They are vicious biters and are aggressive biters, seeking blood meals in order to lay [a] fertilized batch of eggs," said Minco Madon, director of vector control for the Los Angeles area. "They need that protein."

The L.A. County Health Department has for years inspected all plant shipments from China, but some recent shipments of "lucky bamboo" managed to get by officials.

They Bite During the Day

"It bites during the day, as opposed to most mosquitoes that bite only at night — and it's quite vicious," said Dr. Jonathan Fielding, director of the L.A. County Public Health Department. "So that's obviously one concern. But the potential is obviously of concern, as well, and that is to transmit viral infections."

A nursery in Pomona Valley first found the mosquitoes on their plants, and now the public is being warned.

Officials say the key now is to find all of the mosquitoes in Southern California before they lay any eggs and spread.

So far, none of the mosquitoes found have carried any dread disease.

In the northeast, particularly New York City and its suburbs, several deadly cases of the West Nile virus in recent years have been traced to imported mosquitoes. That virus is carried by birds, but transmitted by mosquitoes that, until 1999, were unknown in the United States.

http://abcnews.go.com/sections/us/DailyNews/skeeters010628.html

-- Martin Thompson (mthom1927@aol.com), July 01, 2001.

Nasty buggers. Although the presence of the mosquito (a "competent vector" for certain diseases of special concern) doesn't automatically imply human outbreaks are around the corner, they are a necessary component.

As related facts: recall that yellow fever (for example) was a problem 200 years ago in many areas of the U.S., and the oldest cemeteries in for example Philadelphia are filled with victims' graves. We tend to think of yellow fever as only happening in "the tropics" but that isn't always the case. Another example: malaria used to be widespread. Amazingly, a few small clusters of malaria *with probable person to person transmission* (by mosquito) have occurred in recent years in, for example, Long Island NY. Also, the famous U.S. Centers for Disease Control and Prevention had its origins after WW2 as an outgrowth of the programs to control disease- carrying mosquitoes in the American Southeast.

Info on tiger ‘skeeters to be found at:

http://www.mda.state.md.us/mosquito/tigermos.html

(although sections are specific to Maryland, the basic problem is nicely summarized).

For lots of other sources of information, see:

http://www.floridamosquito.org/

and click on “web links”.

-- Andre Weltman, M.D. (aweltman@state.pa.us), July 02, 2001.

Personally, I like mosquitoes ::::-§

-- spider (spider@web.com), July 02, 2001.