UV luminescence in Jersey Tiger moths

Moths are commonly the target of visual predators such as birds, and hence have evolved some of the most sophisticated of animal pigment patterns. Moths employ coloration for visual misdirection, deterrents, and camouflage, as well as for sexual recognition. Recently, we discovered that all might not be as it seems to human eyes. Noting that both birds and moths have been shown to perceive UV wavelengths, we assessed the coloration of moths under UV lamp light. Under UV lamp light the coloration of some moth species changes. Here, we show that the wings of Jersey Tiger (Euplagia quadripunctaria) moths exhibit fluorescence, a phenomenon observed for the first time in this species. Both the white and red scales of these moths display fluorescence. While UV lamp illumination prompts similar emissions from both white and red scales, 405 nm laser illumination reveals distinct fluorescence spectra. Despite no apparent structural differences observed under SEM between the white, black, and red scales, fluorescence emanates from the entire nanostructured architecture of the scales, indicating a chemical presence throughout. Chemical disparities between the scales are detected via FTIR, though identifying the specific pigment proves elusive. Further investigation is necessary to ascertain the pigments responsible for fluorescence. Additionally, this study prompts exploration of fluorescence patterns in other moth species. The biological significance of this fluorescence phenomenon warrants further inquiry.