Sun, Feb 23, 2020 page9

• Fireflies threatened globally, with light pollution a glaring problem 光害實在太亮 全球螢火蟲遭到威脅

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  Fireflies are under threat globally, with familiar hazards such as habitat loss and pesticides compounded by another peril: humankind’s ubiquitous nighttime artificial light that plays havoc with their balletic nocturnal courtship, scientists said.

  In the most comprehensive worldwide assessment to date of dangers facing these flying beetles, researchers concluded that some of the more than 2,000 firefly species may face extinction threats while others are doing just fine. Using assessments from 350 experts on fireflies from around the world, the researchers determined that the top threat was habitat loss and fragmentation caused by factors such as urbanization, industrialization and agricultural intensification.

  The second-leading threat was light pollution. Fireflies boast specialized light-emitting organs, typically on their lower abdomen, called lanterns. Fireflies flash to communicate as a part of courtship and reproduction. “Light pollution affects lots of nocturnal creatures, but fireflies are especially susceptible to this particular threat,” said biology professor Sara Lewis of Tufts University in Massachusetts, US, who led the research published on Feb. 3 in the journal Bioscience.

  

  Firefly explosion occurred in the mountainous area, known as “the border of three counties,” in Guanshan Borough of Tainan’s Nanhua District on April 25 last year. 去年四月二十五日，台南市南化區關山里的「三縣界」山區發生螢火蟲大爆發。

  Photo: Wu Chun-feng, Liberty Times
  照片：自由時報記者吳俊鋒攝

  “That’s because many — though not all — fireflies rely on bioluminescent courtship signals to find their mates. When their nighttime environment is too bright, it’s difficult for them to see one another’s signals, so they never get to hook up,” Lewis added. Satellite data has shown nighttime light pollution from the incessant flow of electric lights expanding on a global scale.

  The third-leading threat was widespread agricultural use of pesticides. Most exposure occurs during the fireflies’ larval stages because juveniles spend up to two years living below ground or under water. The researchers said that while there is scant data on long-term population trends for most species, there is evidence that these insects have vanished from many places where they formerly were abundant.

  Fireflies, commonly known as “hue kim goo” (fire gold lady) in Hoklo (commonly known as Taiwanese), inhabit every continent but Antarctica, preferring moist habitats like forests, fields and marshes. “Sometimes they flash, sometimes they glow,” said study co-author Avalon Owens, a Tufts biology doctoral student. “Sometimes the females have wings. Sometimes they look like fat larvae with big eyeballs. Some are over 5cm long. Some are less than 1.25cm. The flash color is generally somewhere between green and orange, though some can look kind of bluish.”

  “I know a lot of people who really hate insects, but I’ve never met anyone who doesn’t love fireflies,” Lewis added. “They might be tiny, but they’re among our best ambassadors for Earth’s natural magic.”

  (Reuters)

  全球螢火蟲普遍受到威脅，常見危害包括棲息地喪失和人類使用殺蟲劑。科學家指出，另一項危機使目前情況更為惡化：無所不在的夜晚人造燈光，打亂了螢火蟲夜間如芭蕾舞般的求偶行為。

  在一項目前最廣泛的全球性評估中，研究人員檢視這類飛行甲蟲面臨的危機，並做出以下結論：全世界兩千多種螢火蟲中，其中一些恐怕正面臨絕種威脅，而其他種螢火蟲狀況尚屬良好。研究人員運用全球各地三百五十位螢火蟲專家提供的評估報告，判定首要的威脅來自棲地喪失和破碎，主要是因為都市化、工業化，以及精耕細作的集約農業等因素導致。

  第二項主要威脅則是光害。螢火蟲擁有專門的發光器官，普遍位於它們的下腹部，稱為發光器。螢火蟲們發出閃光進行溝通，這是它們求偶與繁殖行為的其中一環。美國麻薩諸塞州塔夫茨大學的生物學教授莎拉‧路易斯是這篇研究的主持人，她指出：「光害會影響許多夜行性生物，但是螢火蟲特別容易受到這項威脅影響。」該研究已於二月三日發表在期刊《生物科學》上。

  路易斯補充表示：「雖然並非全部如此，但是許多螢火蟲仰賴生物發光的求偶訊號，以找尋交配對象。當它們身處的夜晚環境太過明亮時，就會很不容易看到另一隻螢火蟲的信號，也因此永遠不能配對成功。」從衛星資料可以看到，持續不斷發亮的電燈在夜晚造成光害，已經漫延到全球性的規模。

  第三項主要威脅來自於人類在農業上廣泛使用殺蟲劑。大部分暴露於殺蟲劑中的影響發生在螢火蟲的幼蟲階段，因為幼體會花上最多兩年的時間在地底下或是水中生活。研究人員表示，關於大多數螢火蟲種類長期數量趨勢變化的資料相當缺乏，但是仍有證據顯示，在許多螢火蟲曾經繁衍旺盛的地方，現在已經看不到它們的蹤影。

  螢火蟲台語又稱為「火金姑」，棲息於南極洲以外的每一塊大陸上，它們偏愛森林、田野和沼澤這類潮溼的棲息地。該研究的共同作者、塔夫茨大學的生物學博士生阿瓦隆‧歐文斯表示：「有時候螢火蟲閃爍發光，有時候則是持續發光。」他補充說：「有些種類的母螢火蟲有翅膀，有些種類外觀看起來像是胖胖的幼蟲，帶有一對大眼珠。有些螢火蟲身長超過五公分，有些可以小於一點二五公分。螢火蟲閃光的顏色通常是介於綠色和橘色之間，但有時候看起來也有帶一點藍色。」

  路易斯補充說：「我認識很多人是真的討厭昆蟲，但我從來沒有遇到過不喜歡螢火蟲的人。」她也說：「螢火蟲或許體型很小，但它們可說是代表地球自然界魔法最稱職的大使。」

  （台北時報章厚明編譯）

  Publication Notes

  TODAY’S WORDS
  今日單字

  1. ubiquitous adj. 無所不在的 (wu2 suo3 bu2 zai4 de5) 2. play havoc with phr. 打亂、造成大混亂 (da3 luan4, zao4 cheng2 da4 hun4 luan4) 3. nocturnal adj. 夜間的 (ye4 jian1 de5) 4. courtship n. 求偶行為 (qiu2 ou3 xing2 wei2) 5. bioluminescent adj. 生物發光的 (sheng1 wu4 fa1 guang1 de5) 6. larva n. 幼蟲 (you4 chong2)
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