「ヒマラヤのバイアグラ」冬虫夏草、過剰採取で絶滅危惧種に

【パリＡＦＰ＝時事】国際自然保護連合（IUCN）は9日、ガなどの幼虫に寄生するヒマラヤ産の菌類で、「ヒマラヤのバイアグラ」とも呼ばれる「冬虫夏草」が、中国の伝統薬の需要の増加により絶滅の危機にひんしていると明らかにした。（写真はネパールのドルパ郡の標高4000メートルの高地で冬虫夏草を採集する人。資料写真）
　冬虫夏草の一種、シネンシストウチュウカソウは世界一高価なキノコで、チベット高原にのみ分布し、現地コミュニティーの主要な収入源となっている。
　同種は標高３５００メートル以上の草地で、冬は氷点下になるが永久凍土ではない場所でしか育たない。コウモリガの幼虫の体内で育ち、宿主の頭を突き破りキノコとして現れる。
　同種は何世紀もの間、中国の伝統薬では万能薬で媚薬（びやく）効果があるとして珍重されてきたが、１９９０年代から需要が急増した。
　ネパールでは毎春、村人らが冬虫夏草を採取するために山に入るため、民家や学校から人けがなくなる。この登山には危険が伴こともあるという。
　ＩＵＣＮによると、過剰採取により、過去１５年で生息数は少なくとも３０％減少し、ＩＵＣＮは同種を「絶滅危惧ＩＩ類」として、絶滅のおそれのある野生生物のリストに追加した。
　ＩＵＣＮ菌類保全委員会のグレゴリー・ミュラー委員長は、キノコとキノコを収入源にしているコミュニティーの双方を守るために、持続可能な採取制限が必要だと述べた。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2020/07/13-13:13）

A parasitic fungus that grows inside the ghost moth caterpillar and then kills its host by bursting through its head is itself threatened with extinction, the IUCN said Thursday, as demand surges for Chinese medicine's Himalayan Viagra.
Ophiocordyceps sinensis, the world's most expensive fungus, only grows on the Tibetan Plateau where it has become the main source of income for some communities.
It has been prized as a health tonic and aphrodisiac in Chinese traditional medicine for centuries, but demand has intensified since the 1990s.
Overharvesting has slashed populations by at least 30 percent in the last 15 years, according to the International Union for the Conservation of Nature, which has now listed it as vulnerable to extinction in its directory of threatened animal and plant species.
This is one of the few documented cases of a fungus being threatened by overharvesting, said Gregory Mueller, who heads up IUCN's Fungal Conservation Committee.
He said there needed to be a sustainable harvest programme to protect both the fungus and the communities that rely on it for their incomes.
Ophiocordyceps sinensis is also known as the Caterpillar Fungus, or Yarchagumba, which means summer plant, winter insect in Tibetan.
It is only found in meadows above 3,500 metres (11,550 feet) and forms when the fungus lodges itself in caterpillars and slowly kills them.
To grow, it needs a specific climate with winter temperatures below freezing but where the soil is not permanently frozen.
Harvesting the cone-shaped fungus is highly profitable.
Every spring in Nepal, houses and schools empty as thousands of villagers make the sometimes perilous journey up into the mountains to collect it.
But this year Kathmandu banned the annual trek to harvest the fungus during its lockdown for the coronavirus pandemic.
No definitive research has been published proving its beneficial qualities, but Chinese herbalists believe it boosts sexual performance, hence the nickname Himalayan Viagra.
Boiled in water to make tea, or added to soups and stews, it is said to cure a variety of ailments from fatigue to cancer, to kidney and lung problems.
Researchers say it can, ounce for ounce, fetch up to three times the price of gold in Beijing.
People in China and Nepal have in the past been killed in clashes over Yarchagumba.