Centro de Investigaciones de Plagas e Insecticidas (CONICET), Juan Bautista de La Salle 4397, Buenos Aires, Argentina.
J Insect Physiol. 2011 Oct;57(10):1431-6. doi: 10.1016/j.jinsphys.2011.07.009. Epub 2011 Jul 27.
For many years it has been accepted that DEET interferes with the detection of odours from the host instead of having a repellent effect. However, recent work showed that DEET acts as an odorant molecule and elicits a behavioural response in the absence of other stimuli. Therefore, DEET must promote some phenomenon connected with the stimuli-sensory system interaction, such as a sensory adaptation, where the sensory system regulates its sensitivity to different stimuli intensities during continuous or repetitive exposure. In this work, we studied different aspects of the insect-DEET interaction through behavioural observations. Previous exposure of fifth instar Rhodnius prolixus nymphs to DEET decreased the behavioural response to this repellent. We observed a decrease in repellence after different times of continuous stimulation with DEET in a time-dependent manner. The response to DEET was recovered 10 min after exposure, when insects were continuously stimulated during 5 or 10 min; maximum repellence was recovered 20 min after exposure when insects were stimulated for 20 min. DEET produced a repellent effect when nymphs were exposed only to its vapours. These results suggest that exposure to DEET produces adaptation in R. prolixus nymphs, and that the behavioural response elicited by DEET occurs via olfaction when no other stimuli are present.
多年来，人们一直认为避蚊胺会干扰宿主气味的检测，而不是具有驱避作用。然而，最近的研究表明，避蚊胺作为一种气味分子，在没有其他刺激的情况下会引起行为反应。因此，避蚊胺必须促进与刺激-感觉系统相互作用有关的某些现象，例如感觉适应，在这种适应中，感觉系统在持续或重复暴露于不同刺激强度时调节其对不同刺激的敏感性。在这项工作中，我们通过行为观察研究了昆虫与避蚊胺相互作用的不同方面。第五龄若虫对避蚊胺的先前暴露降低了对这种驱避剂的行为反应。我们观察到，随着时间的推移，避蚊胺的连续刺激会以时间依赖的方式降低驱避率。暴露后 10 分钟，当昆虫连续刺激 5 或 10 分钟时，对 DEET 的反应得到恢复；暴露后 20 分钟，当昆虫刺激 20 分钟时，最大驱避率得到恢复。当若虫仅暴露在避蚊胺的蒸气中时，避蚊胺会产生驱避作用。这些结果表明，避蚊胺暴露会使 R. prolixus 若虫产生适应性，并且当没有其他刺激存在时，避蚊胺引起的行为反应是通过嗅觉发生的。
