到底是什么原因讓蚊子對DEET（避蚊胺,，一種驅(qū)蚊劑）心存顧忌？一些專家相信,，這種強(qiáng)效的驅(qū)蚊劑只不過妨礙了昆蟲對某些更有吸引力的化學(xué)物質(zhì)——例如人體氣味——的嗅覺,。
據(jù)美國《科學(xué)》雜志在線新聞報(bào)道，一項(xiàng)新的研究發(fā)現(xiàn),，蚊子實(shí)際上很討厭DEET的氣味,。在電子顯微鏡下對蚊子的主要嗅覺神經(jīng)細(xì)胞進(jìn)行的分析顯示，DEET實(shí)際上喚醒了蚊子的感覺系統(tǒng),，并且蚊子總是避免飛越僅僅涂有DEET的濾網(wǎng),。研究人員在8月18日的美國《國家科學(xué)院院刊》（PNAS）網(wǎng)絡(luò)版上報(bào)告了這一研究成果。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
