Jakobsson Johan, Henze Miriam J, Svensson Glenn P, Lind Olle, Anderbrant Olle
Department of Biology, Lund University, Sweden.
Department of Biology, Lund University, Sweden; Brain Research Institute, University of Queensland, Australia.
J Insect Physiol. 2017 Aug;101:161-168. doi: 10.1016/j.jinsphys.2017.06.006. Epub 2017 Jul 1.
We investigated whether the spruce seed moth (Cydia strobilella L., Tortricidae: Grapholitini), an important pest in seed orchards of Norway spruce (Picea abies (L.) Karst.), can make use of the spectral properties of its host when searching for flowers to oviposit on. Spectral measurements showed that the flowers, and the cones they develop into, differ from a background of P. abies needles by a higher reflectance of long wavelengths. These differences increase as the flowers develop into mature cones. Electroretinograms (ERGs) in combination with spectral adaptation suggest that C. strobilella has at least three spectral types of photoreceptor; an abundant green-sensitive receptor with maximal sensitivity at wavelength λ=526nm, a blue-sensitive receptor with λ=436nm, and an ultraviolet-sensitive receptor with λ=352nm. Based on our spectral measurements and the receptor properties inferred from the ERGs, we calculated that open flowers, which are suitable oviposition sites, provide detectable achromatic, but almost no chromatic contrasts to the background of needles. In field trials using traps of different spectral properties with or without a female sex pheromone lure, only pheromone-baited traps caught moths. Catches in baited traps were not correlated with the visual contrast of the traps against the background. Thus, visual contrast is probably not the primary cue for finding open host flowers, but it could potentially complement olfaction as a secondary cue, since traps with certain spectral properties caught significantly more moths than others.
我们研究了云杉种子小卷蛾（Cydia strobilella L.，卷蛾科：小卷蛾族），这是挪威云杉（Picea abies (L.) Karst.）种子园中的一种重要害虫，在寻找花朵进行产卵时是否能够利用其寄主的光谱特性。光谱测量表明，花朵以及由它们发育而成的球果，与挪威云杉针叶背景相比，具有更高的长波长反射率。随着花朵发育成成熟球果，这些差异会增大。视网膜电图（ERG）结合光谱适应表明，云杉种子小卷蛾至少有三种光谱类型的光感受器；一种丰富的对绿色敏感的感受器，在波长λ = 526nm处具有最大灵敏度，一种对蓝色敏感的感受器，λ = 436nm，以及一种对紫外线敏感的感受器，λ = 352nm。基于我们的光谱测量以及从视网膜电图推断出的感受器特性，我们计算得出，适合产卵的开放花朵与针叶背景相比，提供了可检测到的消色差对比度，但几乎没有颜色对比度。在使用具有不同光谱特性的诱捕器进行的田间试验中，无论是否带有雌性性信息素诱饵，只有带有性信息素诱饵的诱捕器捕获到了蛾子。诱饵诱捕器中的捕获量与诱捕器相对于背景的视觉对比度无关。因此，视觉对比度可能不是找到开放寄主花朵的主要线索，但它有可能作为次要线索补充嗅觉，因为具有某些光谱特性的诱捕器捕获到的蛾子明显多于其他诱捕器。
