Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 99. (Budapest 2007)
Bálint, Zs., Horváth, Z. E. , Kertész, K. , Vértesy, Z. ; Biró, L. P.: Observations on scale structures and spectroscopic properties of Polyommatus lycaenid butterflies (Lepidoptera: Lycaenidae)
ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Volume 99 Budapest, 2007 pp. 115-127. Observations on scale structures and spectroscopic properties of Polyommatus lycaenid butterflies (Lepidoptera: Lycaenidae) Zs. BÁLINT 1 , Z. E. HORVÁTH 2 , K. KERTÉSZ 2 , Z. VÉRTESY 2 & L. P. BÍRÓ 2 1 Department of Zoology, Hungarian Natural History Museum, H-1088 Budapest, Baross utca 13, Hungary. E-mail: balint@nhmus.hu 2 Department ofNanothechnology, Research Institute for Technical Physics and Materials Science, H-1525 Budapest, POB 49, Hungary. E-mail:biro@mfa.kfki.hu Abstract - The morphology of scale micro- and nanostructures were investigated in three species of the monophyletic Polyommatus eros species group and in two closely related outgroup species P. ariana (MOORE, 1865) and P. icarus (DENIS et SCHIFFERMÜLLER, 1775) by Scanning Electron Microscopy. The optical properties of the blue wing dorsa were studied by reflection spectroscopy in the ultraviolet-visible range. We found ingroup correlations between nanomorphology of the scales and the spectral position of the reflectivity maxima. The closely related species of the P. eros group showed qualitatively similar spectra but quantitatively they revealed characteristic features. The outgroup species P. ariana and P. icarus underlined these observations as they possessed quantitatively distinct scale nanomorphology and their reflectivity maxima were clearly different as compared with those of the P. eros group. We discuss that the optical values of the structural colouration of the species we examined play an important role in pre-mate signaling, which creates a successive barrier between taxa otherwise similar in wing pattern and genital structures. We conclude that reflectance measurements may turn into a cheap and handy tool to probe relationships within a given monophyly, in which taxa are otherwise uniform when traditional taxonomic characters are studied. With 15 figures. Key-words - Discolouration, microstructures, nanostructures, Polyommatus, reflectance, scales, signaling, spectrum. INTRODUCTION Year by year we learn that more and more insects, aquatic organisms, birds (PARKER 2005) and more recently even plants (VIGNERON et al. 2005) relay on so-called photonic crystal type materials to achieve certain biological functions. Photonic crystals, or photonic band gaps (PBG), are materials in
