Insects locate their host plants using mainly visual and olfactory cues, generally of the exploited plant structure. However, when the resource is difficult to access, it could be beneficial to utilise indirect cues, which indicates the presence of reward (e.g., oviposition site or mate). In the present study, we investigated the host-plant location strategy of the monophagous Guatemalan potato moth Tecia solanivora (Lepidoptera: Gelechiidae). The larva of the moth feed exclusively on potato Solanum spp. (Solanaceae) tubers usually hidden below ground. Using electrophysiological and behavioural tests, we characterised the olfactory cues mediating the attraction of the moth towards their host plant. Odour blends were made to represent different potato structures: tubers, foliage, and flowers. Synthetic blends were created by combining potato-emitted compounds that were antennal active which showed positive dose–response. Attraction to these blends of compounds in relation to the mating status of males and females was tested in dual-choice Y-tube assays. Both males and females, virgin and mated, were attracted to a three-compound blend representing flower odour, while foliage and tuber blends attracted neither sexes. Oviposition bioassays indicated additionally that the floral blend enhances oviposition. We show that potato flower odour might indicate the presence of an oviposition site for the female and possibly an increased mating opportunity for both sexes. Our results provide one of the few examples of the use of floral odour as a reliable indicator of host and probably mating possibility for phytophagous insects exploiting a site spatially separated from the flower.

中文翻译：

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危地马拉马铃薯蛾Tecia solanivora的寄主植物定位受花卉挥发物的辅助。

昆虫主要使用视觉和嗅觉线索来定位其寄主植物，通常是所利用植物结构的线索。但是，当资源难以访问时，利用间接提示可能是有益的，它指示奖励的存在（例如，产卵位点或伴侣）。在本研究中，我们调查了单相危地马拉马铃薯蛾Tecia solanivora（鳞翅目：Gelechiidae）的寄主植物定位策略。蛾的幼虫仅以马铃薯茄为食spp。（茄科）块茎通常隐藏在地下。使用电生理和行为测试，我们表征了介导蛾对宿主植物的吸引力的嗅觉提示。进行气味混合以代表不同的马铃薯结构：块茎，树叶和花朵。通过组合具有触角活性并显示出正剂量反应的马铃薯发射化合物来创建合成混合物。在双选择Y管试验中测试了与雄性和雌性交配状态相关的这些化合物混合物的吸引力。雄性和雌性，无论是原始的还是交配的，都被一种代表花味的三化合物混合物所吸引，而叶子和块茎的混合物则没有吸引任何性别。产卵生物测定另外表明，花卉混合物增强了产卵。我们显示马铃薯花的气味可能表明雌性有一个产卵位点，并且可能增加男女的交配机会。我们的研究结果提供了使用花香作为寄主的可靠指标的少数几个例子之一，并且可以利用植物在空间上与花朵分开的位置来吞噬食草昆虫。