Greiner Birgit
Department of Cell and Organism Biology, Lund University, Zoology Building, S-22362 Lund, Sweden.
J Comp Neurol. 2006 Mar 20;495(3):255-62. doi: 10.1002/cne.20882.
The apposition compound eye of the nocturnal polistine wasp Apoica pallens shows, in comparison to the closely related diurnal wasp Polistes occidentalis, specific adaptations to vision at low light intensities. When considering recent work on nocturnal and diurnal bees, general principles for dim-light vision in hymenopterans become evident: The rhabdom diameters in nocturnal bees and wasps are 4 times wider compared to their diurnal relatives, leading to wide receptive fields, which in turn account for a 25-fold higher optical sensitivity. Interestingly, the rhabdom diameters in both nocturnal bees and wasps measure 8 mum, which may represent the maximum width for nocturnal hymenopteran apposition eyes. A ratio of 1.8 times larger eyes is present in the nocturnal bees and wasps, which in A. pallens is achieved by increasing the facet number, instead of enlarging the facets, as in nocturnal bees. Although this initially indicates spatial resolution to be important for the nocturnal wasp, the wide receptive fields of the rhabdoms will reduce its potentially high acuity. As the optical sensitivity alone cannot account for the 8 log units intensity difference between day and night, a possible role of neural summation within the first optic ganglion (lamina) of nocturnal hymenopterans is discussed.
与亲缘关系较近的昼行性胡蜂西方黄胡蜂相比，夜行性马蜂淡色黄胡蜂的并列复眼表现出对弱光环境下视觉的特殊适应性。结合近期有关夜行性和昼行性蜜蜂的研究，膜翅目昆虫在弱光环境下的视觉普遍规律变得清晰起来：夜行性蜜蜂和马蜂的视杆直径比它们的昼行性近亲宽4倍，这导致了更宽的感受野，进而使光学敏感度提高了25倍。有趣的是，夜行性蜜蜂和马蜂的视杆直径均为8微米，这可能代表了夜行性膜翅目并列复眼的最大宽度。夜行性蜜蜂和马蜂的眼睛比昼行性的大1.8倍，在淡色黄胡蜂中，这是通过增加小眼数量实现的，而不像夜行性蜜蜂那样增大小眼尺寸。虽然这最初表明空间分辨率对夜行性马蜂很重要，但视杆宽感受野会降低其潜在的高敏锐度。由于仅光学敏感度无法解释昼夜之间8个对数单位的光强差异，因此本文讨论了夜行性膜翅目昆虫第一视觉神经节（板层）内神经总和的可能作用。
