外刊双语：蚊子的生存之谜？

原文标题：
Malaria
Slumbering swarms
A mystery about malarial mosquitoes’dry-season survival is solved
疟疾
沉睡成群
疟疾蚊子在旱季的生存之谜被解开了
 
The mosquitoes hide, and enter a state of torpor
原来蚊子躲起来进入了休眠

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THE MOSQUITOES that transmit malaria in Africa have short and merry lives.
在非洲传播疟疾的蚊子拥有短暂且快乐的一生。
 
Six or seven weeks is as much as their adults can manage.
它们成年后，最多能活六到七周。
 
To maintain their populations they must lay eggs in water, in which their larvae then grow and pupate.
为了维持它们的种群数量，它们必须在水中产卵，然后它们的幼虫在水中生长和化蛹。
 

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This means such mozzies fly all year round in wet places, but in those that experience pronounced dry seasons, they vanish.
这意味着这种蚊子全年都在潮湿的地方飞行，但在那些经历明显旱季的地方，它们就会消失。
 
In theory, malarial mosquitoes should die out entirely during dry spells that go on for months, for their eggs are insufficiently drought-resistant to last that long.
理论上，携带疟疾的蚊子应该在持续数月的干旱期间完全灭绝，因为它们的卵没有足够的抗旱性，无法持续那么长时间。
 
Nevertheless, days after rains return, so too do the mosquitoes.
事实并非如此，雨后几天，带有疟疾的蚊子又回来了。
 
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This state of affairs, known as the “dry-season malaria paradox”, has confused mosquito researchers for decades.
这种被称为“旱季疟疾悖论”的情况困扰了蚊子研究人员几十年。
 
Some entomologists propose that these early insects are long-distance migrants from places where standing water remains for them to breed in.
一些昆虫学家提出，这些早期的蚊子是长途迁徙而来的，它们是从有水可供繁殖的地方迁徙过来的。
 
But a report in Nature Ecology and Evolution by Roy Faiman of the National Institutes of Health, in Maryland, and Alpha Yaro at the Malaria Research and Training Centre, in Mali, suggests they are actually locals that have endured the dry season by aestivating—the hot-weather equivalent of hibernating.
但是，马里兰州国立卫生研究院的罗伊·费曼和马里疟疾研究和培训中心的阿尔法·亚罗发表在《自然生态学和进化》上的一份报告表明，这些蚊子实际上是土著，它们通过夏眠来度过旱季，一遇到炎热的天气就休眠。
 
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As with hibernation, aestivation means an animal enters a state of torpor, devoting its energies merely to surviving tough conditions rather than being up, about, and, well, animated.
和冬眠一样，夏眠意味着动物进入一种麻木状态，把精力仅仅用于在恶劣的环境中生存，而不是站起来，四处走动，活跃起来。
 
Entomologists sceptical of the migration theory have speculated that mosquitoes use this trick to survive in places with prolonged dry seasons—for example the Sahel, a band of semi-desert that stretches across Africa just south of the Sahara, traversing Mali as it does so.
对迁徙理论持怀疑态度的昆虫学家推测，蚊子利用这种方法在旱季较长的地方生存。例如横跨马里的萨赫勒地区就是如此。萨赫勒地区是撒哈拉以南横跨非洲的半沙漠地带。
 
But evidence has been elusive.
但一直难以找到证据。
 
This is not because of a lack of interest in tracking mosquitoes through the seasons.
这并不是因为人们在旱季对追踪蚊子没兴趣。
 
Quite the contrary. Their role as carriers of one of the world’s most deadly diseases means there is a lot of curiosity about the matter.
恰恰相反，它们作为世界上最致命疾病之一的携带者，人们对它们充满了好奇。
 
What has been lacking is a suitable tool to investigate.
只不过目前缺乏一种合适的调查工具。
 
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Mosquitoes are tiny.
蚊子是微小的。
 
Following them any distance by eye is impossible, and, unlike larger animals, they cannot be fitted with radio collars or similar tracking devices.
用肉眼追踪它们是不可能的，而且与大型动物不同，它们无法安装无线电项圈或类似的追踪装置。
 
Instead, Dr Faiman and Dr Yaro borrowed an idea from ornithology.
取而代之的是，费曼博士和亚罗博士借用了鸟类学的一个办法。
 
If you want to be able to find out in the future whether you have seen a particular bird before, one way is to mark it with a ring.
如果你想在将来知道你是否见过某只鸟，可以用戒指标记它的方法。
 
You cannot literally ring a mosquito, of course, any more than you can collar it.
当然，你不能给蚊子戴上戒指，就像你不能给它戴上项圈一样。
 
But the two researchers came up with an alternative marker: deuterium.
但两位研究人员提出了另一种标记:氘。
 
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Deuterium is a heavy but non-radioactive isotope of hydrogen. (It has a neutron in its nucleus as well as the hydrogen-defining singleton proton.)

氘是一种重氢，是氢的同位素，无放射性。(它的原子核中有一个中子，还有一个定义氢的单态质子。)
 
Like ordinary hydrogen, deuterium can react with oxygen to yield water, known in this case as “heavy” water.
像普通的氢一样，氘可以与氧反应生成水，在这种情况下被称为“重水”。
 
Natural water does contain a small proportion of the heavy variety, but water enriched with the stuff is distinctive and detectable.
自然界的水中确实含有一小部分重质的种类，但是富含这种物质的水是独特的，可以被检测到。
 
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During the final weeks of the wet season (which lasts from May to October), Dr Faiman and Dr Yaro therefore poured heavy water at intervals into 27 mosquito breeding sites in two Malian villages.
因此，在雨季的最后几周（从5月持续到10月），费曼博士和亚罗博士每隔一段时间就向马里两个村庄的27个蚊子繁殖点注入重水。
 
They made sure, in particular, that they topped up each site every time it rained, to stop the heavy water getting too diluted.
他们特别确保，每次下雨时都要给每个繁殖点加重水，以防止其被过度稀释。
 
They also checked that mosquitoes from these sites were, indeed, deuterium rich, and that those from comparable control sites were not.
他们还检查了来自这些繁殖点的蚊子确实富含氘，而来自类似对照地点的蚊子则没有。
 
Sampled at random in the villages, a third of the insects were, by the end of the procedure, deuterium-positive.
在村庄中随机取样，三分之一的昆虫在检查结束时，氘呈阳性。
 
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Then they waited.
然后就陷入了等待。
 
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At the end of the wet season, the breeding sites duly dried up.
雨季结束时，这些繁殖点迅速干涸。
 
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They waited some more.
他们需要等待更长的时间。
 
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In May, the rains returned, and so did the mosquitoes. And, lo, a fifth of them were full of deuterium. They had, in other words, been aestivating.
5月，雨水和蚊子如期而至。你瞧，其中有五分之一的蚊子是被氘标记过的。换句话说，它们一直在休眠。
 
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The next step is therefore to find out just where the insects were holing up while the rains were gone.
因此，下一步就是要找出旱季蚊子的藏身之处。
 
If these shelters can be identified, they can be attacked.

如果这些藏身之处能被识别出来，人们就可以将其捣毁。

 
Alternatively, special efforts might be made to ambush the aestivators as they wake up, by extensive insecticide-spraying campaigns at the beginning of the rainy season.
或者，人们可以在它们夏眠醒来之时采取特别措施伏击它们，即在雨季开始时大规模喷洒杀虫剂。
 
Either or both of these could put a significant dent in local mosquito populations—which would, in turn, make malaria less of a problem.
这两种方法中的一种或两种都能显著减少当地蚊子的数量。反过来，这意味着疟疾不再是一个问题。
 
（恭喜读完，本篇英语词汇量700左右）
原文出自：2022年10月14日《TE》Science&technology版块。

精读笔记来源于：自由英语之路

本文翻译整理: Maree

本文编辑校对: Irene
仅供个人英语学习交流使用。

【补充资料】（来自于网络）

Malaria（疟疾）是由疟原虫属寄生虫所致。受感染雌性按蚊通过叮咬将寄生虫传给人类。共有五种寄生虫会导致人类疟疾，其中恶性疟原虫和间日疟原虫危害最大。恶性疟原虫是最致命的疟疾寄生虫，在非洲大陆上最流行。间日疟原虫是撒哈拉以南非洲之外大部分国家的主要疟疾寄生虫。疟疾最初的症状（发热、头痛和寒战）通常会在受感染蚊虫叮咬10-15天后显现。症状可能较轻，难以发现是疟疾。如果不予以治疗，恶性疟原虫疟疾可能在24小时内发展成严重疾病，甚至死亡。2020年，世界将近有一半人口面临疟疾风险。一些人群感染疟疾并发展为严重疾病的风险比其他人群高得多。高风险人群包括婴儿、五岁以下儿童、孕妇和艾滋病毒感染者/艾滋病患者，以及搬到存在疟疾密集流行地区的无免疫力的农民工、流动人口和旅行者。
 
萨赫勒（Sahil，意为“边缘”）是非洲北部撒哈拉沙漠和中部苏丹草原地区之间的一条长超过3,800千米的地带，从西部大西洋伸延到东部非洲之角，横跨塞内加尔、毛里塔尼亚、马里、布基纳法索、尼日尔、尼日利亚、乍得、苏丹共和国，南苏丹共和国和厄立特里亚10个国家。
 
【重点句子】（3 个）
This means such mozzies fly all year round in wet places, but in those that experience pronounced dry seasons, they vanish.
这意味着这种蚊子全年都在潮湿的地方飞行，但在那些经历明显旱季的地方，它们就会消失。
 
As with hibernation, aestivation means an animal enters a state of torpor, devoting its energies merely to surviving tough conditions rather than being up, about, and, well, animated.
和冬眠一样，夏眠意味着动物进入一种麻木状态，把精力仅仅用于在恶劣的环境中生存，而不是站起来，四处走动，活跃起来。
 
Either or both of these could put a significant dent in local mosquito populations—which would, in turn, make malaria less of a problem.
这两种方法中的一种或两种都能显著减少当地蚊子的数量。反过来，这意味着疟疾不再是一个问题。