科普知识学英语 飞蛾依靠嗅觉寻找异性

海量资料下载 免费学习英语 www.englishvip.com/xinlw.htm （申请网址） An international team of researchers, including an entomologist at the University of California, Riverside, has an explanation for why we see so many hybrid（混合的，杂种的） moths in nature. The team closely examined the behavior and the olfactory（嗅觉的） circuitry of male moths and found an answer in female-produced pheromones -- chemicals generally consisting of a blend of two to several derivatives of fatty acids. Male moths use pheromones（信息素）to find females. To avoid mating with the wrong moth species, the pheromone blends are specific for each moth species, with only males of the same species "understanding" these volatile messages -- a result shown many times during the last 40 years of research on moth pheromones. The researchers focused on the European corn borer, a moth species in which males often mate with females from a different strain.   Strains are variants, forms of the same species. While two different species cannot mate with each other, strains, being from the same species, can.   To understand the mating behavior of the European corn borer, first, the researchers followed the flights of males to female pheromones in a wind tunnel. Each strain of the European corn borer uses a blend of pheromone components in a very specific ratio. But to their surprise, the researchers found that as the male moth flies upwind along the pheromone plume, its olfactory circuitry loses the ability to measure this ratio.   "This happens because receptors in the moth brain for each pheromone component have differential rates of sensory adaptation and each type of receptor begins to fire at a different rate, causing the input into the moth's brain to change as the moth flies along the plume," explained Teun Dekker, a former UCR graduate student and now an associate professor at the Swedish University of Agricultural Sciences, and a coauthor on the study. "To overcome this mismatch, moths rely on the ratio they detected in their first encounter with the plume."   According to the researchers, this "mental short cut" is needed for male moths to continue their orientation along the plumes which, from a sensory input viewpoint, seem to be changing in pheromone component ratio.   "Once male moths lock onto a pheromone plume, they are much less attuned to blend quality," Dekker said. "In other words, males fly even to blends that were initially unattractive, and so can mate with females of different strains that they would not have approached otherwise, explaining why we find hybrid moths in nature."   Study results appeared online April 15 in the Proceedings of the National Academy of Sciences. 一个国际研究小组的研究人员，包括河滨加州大学的昆虫学家，有一个解释，为什么我们看到这么多的混合（混合的，杂种的）在自然界的飞蛾。团队密切审查的行为和嗅觉（雄蛾的嗅觉的）电路，并在女性生产的费洛蒙找到了答案-一般由两个融合了几种脂肪酸衍生物的化学品。雄蛾使用费洛蒙（信息素）的女性。为了避免错误的蛾类交配信息素混合具体每个蛾，只有男性的同一物种的“理解”这些挥发性消息-多次测试结果显示，在过去40多年的研究蛾费洛蒙。研究人员集中在欧洲玉米螟男性往往从不同的菌株与雌性交配，蛾类。   菌株的变体形式的同一物种。当两个不同的物种不能相互交配，株，即来自同一物种，可以。   要了解欧洲玉米螟的交配行为，首先，研究人员随后在风洞中的雌性信息素的男性的航班。欧洲玉米螟的每个菌株的使用信息素组分的共混物，在一个非常具体的比例。但他们吃惊的是，研究人员发现，雄蛾飞沿着信息素羽逆风，其嗅觉电路失去能力来衡量这个比例。   “这种情况发生，因为每个信息素成分在飞蛾的大脑受体具有感觉适应差分率和每种类型的受体开始火以不同的速率，导致成飞蛾的大脑变更蛾的输入沿羽飞，”解释特恩·德克尔，前加州大学河滨分校的研究生，现在在瑞典农业科学大学副教授，研究的共同作者。“为了克服这种不匹配，飞蛾依靠羽在他们的第一次相遇，他们检测的比例。”   据研究人员介绍，这种“精神的短切”是需要继续自己的定位，从感官输入的角度来看，似乎正在改变信息素成分比沿羽毛的雄蛾。   ，“德克尔说：”一旦雄蛾锁定到信息素羽，他们不太适应混合质量。“换言之，男性即使飞最初不起眼的混合，因此可以与女性不同菌株交配，他们就不会走近，否则，解释为什么我们发现混合飞蛾，在本质上。”   研究结果出现于4月15日在国家科学院的论文集。 “成千上万人疯狂下载。。。。。。 更多价值连城的绝密英语学习资料， 洛基内部秘密英语，技巧，策略 请在 网上 申请报名” 洛基国际英语 竭诚为您服务