到底是什么原因让蚊子对DEET（避蚊胺，一种驱蚊剂）心存顾忌？一些专家相信，这种强效的驱蚊剂只不过妨碍了昆虫对某些更有吸引力的化学物质——例如人体气味——的嗅觉。

    据美国《科学》杂志在线新闻报道，一项新的研究发现，蚊子实际上很讨厌DEET的气味。在电子显微镜下对蚊子的主要嗅觉神经细胞进行的分析显示，DEET实际上唤醒了蚊子的感觉系统，并且蚊子总是避免飞越仅仅涂有DEET的滤网。研究人员在8月18日的美国《国家科学院院刊》（PNAS）网络版上报告了这一研究成果。

原始出处：

PNAS，doi: 10.1073/pnas.0805312105，Zainulabeuddin Syed，Walter S. Leal

Mosquitoes smell and avoid the insect repellent DEET

Zainulabeuddin Syed and Walter S. Leal*

Abstract
The insect repellent DEET is effective against a variety of medically important pests, but its mode of action still draws considerable debate. The widely accepted hypothesis that DEET interferes with the detection of lactic acid has been challenged by demonstrated DEET-induced repellency in the absence of lactic acid. The most recent hypothesis suggests that DEET masks or jams the olfactory system by attenuating electrophysiological responses to 1-octen-3-ol. Our research shows that mosquitoes smell DEET directly and avoid it. We performed single-unit recordings from all functional ORNs on the antenna and maxillary palps of Culex quinquefasciatus and found an ORN in a short trichoid sensillum responding to DEET in a dose-dependent manner. The same ORN responded with higher sensitivity to terpenoid compounds. SPME and GC analysis showed that odorants were trapped in conventional stimulus cartridges upon addition of a DEET-impregnated filter paper strip thus leading to the observed reduced electrophysiological responses, as reported elsewhere. With a new stimulus delivery method releasing equal amounts of 1-octen-3-ol alone or in combination with DEET we found no difference in neuronal responses. When applied to human skin, DEET altered the chemical profile of emanations by a “fixative” effect that may also contribute to repellency. However, the main mode of action is the direct detection of DEET as indicated by the evidence that mosquitoes are endowed with DEET-detecting ORNs and corroborated by behavioral bioassays. In a sugar-feeding assay, both female and male mosquitoes avoided DEET. In addition, mosquitoes responding only to physical stimuli avoided DEET.