Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, 35020 Legnaro, Padova, Italy.
Eye Hospital, University Medical Centre, Grablovičeva 46, 1000 Ljubljana, Slovenia.
Biol Lett. 2021 Feb;17(2):20200736. doi: 10.1098/rsbl.2020.0736. Epub 2021 Feb 17.
Processionary caterpillars of (in Europe) and (in Australia) (Lepidoptera: Notodontidae) form single files of larvae crawling head-to-tail when moving to feeding and pupation sites. We investigated if the processions are guided by polarization vision. The heading orientation of processions could be manipulated with linear polarizing filters held above the leading caterpillar. Exposure to changes in the angle of polarization around the caterpillars resulted in corresponding changes in heading angles. Anatomical analysis indicated specializations for polarization vision of stemma I in both species. Stemma I has a rhabdom with orthogonal and aligned microvilli, and an opaque and rugged surface, which are optimizations for skylight polarization vision, similar to the dorsal rim of adult insects. Stemmata II-VI have a smooth and shiny surface and lobed rhabdoms with non-orthogonal and non-aligned microvilli; they are thus optimized for general vision with minimal polarization sensitivity. Behavioural and anatomical evidence reveal that polarized light cues are important for larval orientation and can be robustly detected with a simple visual system.
（在欧洲）和（在澳大利亚）的列队毛毛虫（鳞翅目：枯叶蛾科）在移动到取食和化蛹地时，会形成一列列幼虫头尾相连地爬行。我们研究了这些列队是否受到偏振光视觉的引导。通过在领头毛毛虫上方放置线性偏振滤光片，可以操纵列队的行进方向。暴露在毛毛虫周围偏振角的变化会导致行进角度相应的变化。解剖分析表明，这两个物种的 I 背板对偏振视觉有特殊的适应。I 背板有一个具有正交和对齐的微纤毛的光感受器，以及一个不透明且粗糙的表面，这是对日光偏振视觉的优化，类似于成虫的背面边缘。背板 II-VI 具有光滑而有光泽的表面和具有非正交和非对齐的微纤毛的叶状光感受器；因此，它们针对具有最小偏振灵敏度的一般视觉进行了优化。行为和解剖学证据表明，偏振光线索对幼虫的定向很重要，并且可以通过简单的视觉系统可靠地检测到。
