What green apple from China goes after rice?

[xchrom]

http://www.elpais.com/articulo/english/What/green/apple/from/China/goes/after/rice/elpepueng/20110919elpeng_6/Ten

Not even drying out half of the Ebro River Delta, in Tarragona province, or dumping quicklime into irrigation channels has managed to remove their little shells from the rice paddies. The apple snail has continued to give farmers headaches for the third year in a row since it first appeared in northern Spain, and now the plague threatens to reach the south.

It is a highly resistant species that reproduces very quickly, and it has been spreading slowly but surely throughout the area since 2009, affecting 9,500 hectares of land. And this, despite the

3.5 million eurosthe Catalan regional government has spent since last year to eradicate the species by taking unprecedented measures: leaving the hardest-hit 9,500 hectares on the left side of the delta without water for nine months, and filling the irrigation ditches with quicklime.

"No country has managed to eradicate this plague," says Ravindra Joshi, an Indian biologist who has been studying the apple snail and its effects on crops since 1980. "After the species is detected, it takes about four years before crop damage occurs," he says. Next year, he predicts, the delta will start to feel the full effects of the animal. "By then, it's usually a catastrophe," says Joshi.

[kristopher]

1. What is the link to China? They are originally from South America...

And they're now common around the world because they are used to clean aquariums.

I googled "apple snail" "green apple snail" and "Invasive species apple snail" and saw nothing that corroborates the storyline in the OP. If it is a problem for agriculture, it is one that doesn't seem to have gained any attention yet.

[xchrom]

3. Ebro Delta: Invasion of the Apple Snail

http://geographyfieldwork.com/EbroDeltaAppleSnailInvasion.htm

Hundreds of thousands of snails that grow to the size of a golf ball are not only taking over and eating the Ebro delta rice fields but also threaten to destroy the delta ecosystem. At the moment, the snails have taken over the rice fields on the left bank, occupying a third of the 32,000 hectares of Natural Park, and have begun to spread to the other side.

In order to halt their advance and destroy them, the farmers have applied the drastic measure of leaving 9,500 hectares of paddy fields dry for six months instead of the usual three. The measures are supported by the Ebro Delta Community authorities, which through its grants have forced the fields to remain flooded through most of the year and thus promote the habitat of migratory birds.

The economic losses are not significant at the moment, but rice farmers fear serious consequences in the medium term if not remedied soon.

The ravages of Pomacea insularum, scientific name of the apple snail species identified in the delta, were previously known only in countries of South America and Asia. The snail is one of many invasive species located in the final stretch of the Ebro and a Government report warns of the risk that "Delta will become the gateway for invasive species of this kind in Europe."


http://www.applesnail.net/content/main.htm
The apple snail website
Update: In late July 2009 an incipient invasion by Pomacea canaliculata was detected in the Ebro Delta, on the Mediterranean shore of Catalonia, Spain. By early September the spread of this applesnail was tremendous, with huge economic losses to rice cultivation. Research on this population's biology and possible control methods is ongoing. TV news on the topic: http://www.tv3.cat/videos/1478229/El-caragol-poma-envaeix-lEbre.


Apple snails take over the Ebro delta
http://www.typicallyspanish.com/news/publish/article_31433.shtml

The snail arrived in Spain four years ago and all attempts to erradicate it have failed.

A plague of apple snails are taking over the delta of the Ebro river, Tarragona, and are proving resistant to all attempts to remove them.

The Pomacea Canaicilata originated in South America and is thought to have reached the Ebro in an accidental escape from the installations of a tropical fish breeder in 2009. The snails eat anything vegetable under the water, and have a dramatic effect on the communities and habitats of other species.

One expert told El País that the expansion can be halted but they cannot be eradicated. Even attempts of using quicklime and other toxic products have proved unsuccessful. Indian biologist, Ravindra Joshi, who has been studying the species since 1980, told the paper that no country has ever proved successful against the snail.

Read more: http://www.typicallyspanish.com/news/publish/article_31433.shtml#ixzz1YPu4cS7n

[kristopher]

4. Thanks for the reply.

I didn't intend to question the problem in Spain. I accept that as legitimate.

But there doesn't appear to be any link to China as the headline implies, nor does this seem to be a *major* problem since they have long been spread globally for aquariums. in spite of that transport mechanism there is no history of them as a widespread threat.

I also have to confess that on my personal scale ranking the inport of ecological issues, the problem of invasive species in general doesn't rank particularly high. That isn't to say in an way that it isn't a REAL problem, for it unquestionably is; it just has to stand in a long line of other real problems competing for attention and resources.

[Ready4Change]

2. Are they edible?

People eat worse things.