Stange Gert
Research School of Biological Sciences, Australian National University, P.O. Box 475, Canberra ACT 2601, Australia Fax: +61 6 249 3808; e-mail:
Oecologia. 1997 May;110(4):539-545. doi: 10.1007/s004420050192.
Sensory organs that detect CO are common in herbivorous moths and butterflies, but their function has been unclear until now. As the CO gradients in the vicinity of a host plant depend on its physiological condition, CO could provide a sensory cue for the suitability of the plant as a larval food source. This study investigated whether changing the atmospheric CO concentration affected oviposition by Cactoblastis cactorum on its host, the cactus Opuntia stricta. On host plants exposed to rapid fluctuations in CO concentration, the frequency of oviposition was reduced by a factor of 3.2 compared to the control. As the fluctuations mask the much smaller CO signals generated by the plants, this suggests that those signals constitute an important component of the host identification process. On host plants exposed to a constant background of doubled CO, oviposition was also reduced, by a factor of 1.8. An increased background reduces host signal detectability, partially as a consequence of a general principle of sensory physiology (Weber-Fechner's law), and partially due to other factors specific to CO-receptor neurons.
能够检测一氧化碳的感觉器官在食草蛾和蝴蝶中很常见，但直到现在其功能仍不清楚。由于寄主植物附近的一氧化碳梯度取决于其生理状况，一氧化碳可能为该植物作为幼虫食物来源的适宜性提供一种感官线索。本研究调查了改变大气一氧化碳浓度是否会影响仙人掌螟在其寄主植物——仙人掌上的产卵情况。与对照相比，在暴露于一氧化碳浓度快速波动的寄主植物上，产卵频率降低了3.2倍。由于这些波动掩盖了植物产生的小得多的一氧化碳信号，这表明这些信号是寄主识别过程的一个重要组成部分。在暴露于一氧化碳浓度翻倍的恒定背景下的寄主植物上，产卵也减少了，减少了1.8倍。背景增加会降低寄主信号的可检测性，部分是由于感觉生理学的一个普遍原理（韦伯-费希纳定律），部分是由于一氧化碳受体神经元特有的其他因素。
