为什么有些人那么招蚊子？
最要命的体质，除了招黑，还有招蚊子。
盛夏时节，除了酷热，最让人难以忍受的恐怕就是被蚊子咬，让人更加难以忍受的则是，周围有一圈人，但蚊子只咬你一个！为什么被蚊子咬的总是你？
Some people can sit outside all summer long and not suffer from mosquito bites. Others turn into an itchy mess despite bathing in DEET and never leaving the purple glow of the bug zapper.
有些人可以整个夏天坐在户外乘凉却不被蚊子叮咬，而另有一些人即便用含驱蚊胺的沐浴露洗浴、随身带着灭蚊灯，却仍遭蚊子叮咬而奇痒难耐。
zapper['zæpɚ]：n. 微波灭虫器
It's mostly about the invisible chemical landscape of the air around us. Mosquitoes take advantage of this landscape by using specialized behaviors and sensory organs to find victims by following the subtle chemical traces their bodies leave behind.
这主要是因为我们身体周围空气中肉眼看不见的化学成分。通过特殊习性和感觉器官，蚊子利用这种化学环境，跟踪人体留下的细微化学痕迹找到叮咬对象。
In particular, mosquitoes rely on carbon dioxide to find their hosts. When we exhale, the carbon dioxide from our lungs doesn't immediately blend with the air. It temporarily stays in plumes that mosquitoes follow like breadcrumbs.
具体来说，蚊子能够靠人体释放的二氧化碳找到它们叮咬的对象。当我们呼气时，从肺里呼出的二氧化碳并非立即与空气混合，而是暂时形成类似于面包粉的团块状气流，而蚊子会跟踪这种气流。
plume [pluːm]：n. 羽毛；羽毛装饰物；（尤指污染物）一团物质
"Mosquitoes start orienting themselves to those pulses of carbon dioxide and keep flying upwind as they sense higher concentrations than the normal ambient air contains," said Joop van Loon, an entomologist at Wageningen University in the Netherlands. Using carbon dioxide, mosquitoes can lock onto targets from up to 164 feet (50 meters) away.
荷兰瓦赫宁恩大学的昆虫学家约普·范隆说：“蚊子开始自我定位，跟踪那些二氧化碳气流，并在它们感觉到二氧化碳浓度比正常环境空气的浓度高时保持逆流飞行。”利用二氧化碳，蚊子可以锁定164英尺（约合50米）以外的目标。
upwind[ʌp'wɪnd]：adv. 逆风地
ambient air： 环境空气
entomologist[,ɛntə'mɑlədʒɪst]：n. 昆虫学者
Things start getting personal when mosquitoes get about 3 feet (1 meter) away from a group of potential targets. In close quarters, mosquitoes take into account a lot of factors that vary from person to person, including skin temperature, the presence of water vapor and color.
当蚊子飞到离一群潜在目标大约3英尺远时，就开始区分每个人的不同情况。在近距离时，蚊子考虑很多因人而异的因素，包括皮肤温度、水汽的存在和颜色。
close quarters：近距离
Scientists think the most important variable mosquitoes rely on when choosing one person over another are the chemical compounds produced by the colonies of microbes that live on our skin.
科学家们认为，蚊子选择某个特定的人作为叮咬目标依据的一个最重要因素是，皮肤上微生物菌落产生的化学成分。
"Bacteria convert the secretions of our sweat glands into volatile compounds that are taken through the air to the olfactory system on the head of the mosquitoes," Van Loon told Live Science.
范隆告诉美国趣味科学网站说：“细菌把人类汗腺的分泌物变成挥发性混合物，通过空气进入位于蚊子头部的嗅觉系统。”
secretion [sɪ'kriːʃ(ə)n]：n. 分泌；分泌物
volatile ['vɒlətaɪl]：adj. [化学]挥发性的；不稳定的
olfactory [ɒl'fækt(ə)rɪ]：adj. 嗅觉的；味道的
These chemical bouquets are complex, including upward of 300 different compounds, and they vary from person to person based on genetic variation and environment.
这些混合物的化学气味很复杂，含有300多种成分，而且因为基因差异和环境不同，因人而异。
upward of：超过，多于
"If you compare a father and daughter in the same household, there can be differences in the ratios of the chemicals the microbes are making," said Jeff Riffell, an associate professor of biology at the University of Washington who has studied mosquito attraction.
美国华盛顿大学研究蚊子吸引力的生物学副教授杰夫·里费尔说：“即使拿一个家庭里的父亲与女儿做比对，微生物产生的化学物质比例可能也有差异。”
For instance, men with a greater diversity of skin microbes tended to get fewer mosquito bites than men with less diverse skin microbes did, a 2011 study in the journal PLOS ONE found. Moreover, men with less diverse microbes tended to have the following bacteria on their bodies: Leptotrichia, Delftia, Actinobacteria Gp3 and Staphylococcus, the researchers said.
譬如，2011年发表在美国《公共科学图书馆·综合》杂志上的一篇研究报告发现，皮肤微生物多样性较高的男性往往比皮肤微生物多样性较低的男性少招蚊子叮咬。而且研究人员称，皮肤微生物多样性较低的男性，他们皮肤上往往有下列几种细菌：纤毛菌、代尔夫特菌、放线菌Gp3和葡萄球菌。
In contrast, men with a diverse array of microbes tended to have the bacteria Pseudomonas and Variovorax on their skin, that study found.
研究发现，相比之下，有多种多样微生物的男性，在他们的皮肤上往往有假单胞菌和贪嗜菌。
Subtle differences in the composition of these chemical bouquets can account for big differences in how many bites a person gets. The composition of those microbial colonies can also vary over time in the same individual, particularly if that person is sick, Riffell said.
这些化学气味成分的细微差异在一个人遭蚊子叮咬时会产生巨大差异。里费尔说，同一个人，这些微生物菌落的组成也可能随时间变化而不同，尤其是在此人生病的时候。
We don't have much control over the microbiomes on our skin, but Riffell did offer some advice based on his research.
我们对皮肤上的微生物没有太多控制权，但里费尔根据他的研究结果给出了一些建议。
microbiome：微生物组，微生物群系
"Mosquitoes love the color black," so consider wearing something lighter at your next cookout, he said.
他说，“蚊子喜欢黑色”，因此下次露天烧烤时，可以考虑穿浅色衣物。
cookout ['kʊkaʊt]：n.（美）野外郊游时烹调的野餐；野烹食物
关于为什么有的人容易招蚊子，除了以上原因，还有很多说法：体温说，血型说，二氧化碳说……今天就来给大家上一堂科普课，告诉你为什么有的人特别招蚊子“喜欢”，小本本准备起来！
1、容易流汗，体温较高
汗液是蚊子觅食的信号之一，所以往往汗液量比较多的人更容易受到蚊子的“青睐”。这是因为汗液中含有乳酸、氨基酸和氨类化合物，容易吸引蚊子的注意。另外，蚊子的触角内有一个受热体，对温度很敏感，而汗液较多的人体表散热快，故而对蚊子的吸引力更大。
2、呼出的二氧化碳比较多
科学家研究发现，蚊子身上有一个触须居然可以感受到50米外的二氧化碳浓度。因此，产生二氧化碳越多的人，越能吸引蚊子。也可以说，新陈代谢较快的人越招蚊子，一般来说，像小孩，体型较大，孕妇，肺活量大的人更容易招蚊子喜欢哦。
3、身体有刺激性较大的气体
蚊子的嗅觉是非常灵敏的，特别是对一些刺激性较大的气体非常的敏感。所以，那些爱化妆的人往往比不化妆的人更容易招惹蚊子。因为很多化妆品中都会有大量的香气，这对蚊子来说可是不小的诱惑。
那么，你是容易招蚊子的体质吗？
来源：中国日报网英语点津 编辑：许雅宁
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