最近科学网上转发了一篇称作美洲新艾滋病的报道（http://news.sciencenet.cn/htmlnews/2012/5/264928.shtm），这种病叫查加斯病（Chagas disease），由猎蝽科的锥蝽传播，引起不少人对蝽类昆虫的恐惧。  

 

蝽类昆虫在我们生活中常见，如臭蝽、盲蝽、水黾、负子蝽，有陆生的，也有水生的，其典型特征是它们成虫的前翅为“半翅”，靠基部的半段为革质，较坚硬，无翅脉，而端部的半段为膜质，常有翅脉。虽然它们都长着刺吸式的口器，但食性却大不相同。绝大多数的蝽类昆虫吸食植物的汁液，还有相当一部分主要捕食其它的昆虫，水生的种类则除了捕食一些其它节肢动物外，还吃一些小鱼和蝌蚪。只有少数的种类是吸血的，寄居在脊椎动物、鸟和蝙蝠体上和巢穴，而吸食人血的种类很少，有锥蝽和臭虫。  

 

锥蝽对昆虫生理学做出过很大的贡献。大名鼎鼎的英国昆虫生理学家Vincent Wigglesworth用锥蝽（Rhodnius prolixus） 做了一系列经典实验，成为激素对变态调控研究的范例。锥蝽的幼期有五龄，每一龄都需要吸血，在一定时间后脱皮进入下一龄， 第五龄的幼虫再脱一次就变为成虫。Wigglesworth把一头初龄幼虫与另一头正蜕皮的五龄幼虫的头切掉后颈部相对接起来（见下图），初龄幼虫就会发育出成虫的特征。由于两个虫体的神经系统并不相连，但血液可从一体传递到另一体，因而断定诱导了变态的因子是激素。他还做实验，把一个叫咽侧体的器官从三龄幼虫体内摘除后，幼虫就变成早熟的成虫，而在五龄幼虫内移植四龄幼虫的咽侧体，五龄若虫就蜕变成超龄的幼虫而不是成虫。这是对咽侧体产生的一种昆虫重要激素----保幼激素（juvenile hormone）的首次阐述。后来，Vincent Wigglesworth被伊丽莎白女王封为爵士。

    

在美洲，传播查加斯病的锥蝽见于美国南部、墨西哥、中美洲和南美洲， 出没于家居环境差的居室、厩舍的墙缝、地板缝以及鼠类、鸡犬等动物的巢穴等。在我国华南地区也有锥蝽，应有所警惕。下图是锥蝽传播查加斯病的侵染循环。  

 

       

     

（图片来自网络）

       

本人在2012年8月19-25日参加了在韩国大邱举办的第二十四届国际昆虫学大会。大会第一天颁发了 Wigglesworth奖，得主是澳大利亚研究飞蝗生理学的Steve Simpson教授。Steve做了题为“A Tale of Swarms, Cannibals, Obesity and Ageing”的大会报告，也作为Wigglesworth Memorial Lecture。英国皇家昆虫学会发了一个小册子，上面是这样介绍 Wigglesworth的：

"PROFESSOR SIR VINCENT WIGGLESWORTH was undoubtedly one of Britain's greatest entomologists. He is probably best known for his work on the South American blood sucking bug, Rhodius prolixus (still known affectionately in scientific circles as Wigglesworth's bug). He recognized that animal physiology and function could be studied through insects instead of mice or other laboratory animals, progressing the field of entomology beyond simple collection and classification. His main findings were in the field of insect hormones, their secretory organs and cells, and how these controlled growth, moulting and reproduction. This research was used for the basis of his seminal work, Principles of Insect Physiology, which was to become the standard text not only for his students in Cambridge, but also for scientists worldwide, firmly establishing the new science of insect physiology on the world stage.

His pioneering work began in the twenties and, 70 years later, he was still working in his Cambridge laboratory long after official retirement. A true scientist, he was able to adapt to the changing world around him, always using the latest instruments and methods in his laboratory, and ensuring his research was regularly published. Publishing eight books, two education readers, and around 300 papers, Wigglesworth has left his mark as one of the most productive biologists of the 20th Century.

The Wigglesworth Memorial Lecture and Medal, named in his honour, is awarded every four years to a researcher who, in the judgement of the Trustees, has done outstanding work and who best reflects Wigglesworth's standards of personal involvement in every aspect of research."

2012年8月31日录