Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91, Stockholm, Sweden.
Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden.
Sci Rep. 2019 Oct 25;9(1):15309. doi: 10.1038/s41598-019-51834-1.
Insects searching for resources are exposed to a complexity of mixed odours, often involving both attractant and repellent substances. Understanding how insects respond to this complexity of cues is crucial for understanding consumer-resource interactions, but also to develop novel tools to control harmful pests. To advance our understanding of insect responses to combinations of attractive and repellent odours, we formulated three qualitative hypotheses; the response-ratio hypothesis, the repellent-threshold hypothesis and the odour-modulation hypothesis. The hypotheses were tested by exposing Drosophila melanogaster in a wind tunnel to combinations of vinegar as attractant and four known repellents; benzaldehyde, 1-octen-3-ol, geosmin and phenol. The responses to benzaldehyde, 1-octen-3-ol and geosmin provided support for the response-ratio hypothesis, which assumes that the behavioural response depends on the ratio between attractants and repellents. The response to phenol, rather supported the repellent-threshold hypothesis, where aversion only occurs above a threshold concentration of the repellent due to overshadowing of the attractant. We hypothesize that the different responses may be connected to the localization of receptors, as receptors detecting phenol are located on the maxillary palps whereas receptors detecting the other odorants are located on the antennae.
昆虫在寻找资源时会接触到复杂的混合气味，其中通常既包含吸引物质也包含排斥物质。了解昆虫如何应对这种复杂的线索对于理解消费者-资源相互作用至关重要，同时也有助于开发控制有害害虫的新工具。为了深入了解昆虫对有吸引力和排斥性气味组合的反应，我们提出了三个定性假设：反应比例假设、排斥阈值假设和气味调节假设。通过在风洞中暴露黑腹果蝇来检验这些假设，这些气味组合包括醋作为引诱剂和四种已知的排斥剂：苯甲醛、1-辛烯-3-醇、土臭素和苯酚。对苯甲醛、1-辛烯-3-醇和土臭素的反应支持了反应比例假设，该假设假设行为反应取决于引诱剂和排斥剂之间的比例。对苯酚的反应则更支持排斥阈值假设，即由于对引诱剂的遮蔽，只有在排斥剂的浓度超过阈值时才会产生厌恶感。我们假设这些不同的反应可能与受体的定位有关，因为检测苯酚的受体位于下颚须上，而检测其他气味的受体则位于触角上。
