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)

Sizes and ratios of scale structures were measured and calculated with relevant commands of the program BioPhot Analyzer developed jointly by our home institutes in the frame of the project BioPhot (see Acknowledgements). Length and distance of the longitudinal ribs (LR) and the cross ribs (CR) were measured, and the filling factors (FF) of the pepper-pot structures can be seen in the windows (microcells) of the scales have been calculated. The 3D lattices (pepper-pot structures sensu ELIOT) are divided into irregular and distinct domains of complex chitinous material having different rates between closed (chitinised) and open (empty) spaces, this ratio is called the FF. The FF and the complex 3D arrangement of the filled and empty volumes determine the hue of the blue colour generated by the wing dorsal surfaces. Male individuals of each species have been studied and measured; to determine the variability of spectral characteristics we selected five individuals of each species. The data of the specimens are listed in the Appendix I. The reflectance spectra were always measured under normal incidence. According to our observations, this was reliable as the individuals revealed the same spectral characteristics. When deviations from the reflectance typical for the taxon were observed, this could be associated with a damaged wing. Micro- and nanostructures can be damaged by the relaxing procedure before the specimen is placed on the setting board in the museum, but usually such alteration can be identified by examination with the naked eye. Normal incidence reflectance spectra of the butterfly wings were recorded using an Avantes 2048 fiber optic spectrometer in the ultraviolet-visible-near-infra-red (UV-VIS-NIR) range. A diffuse white standard (Avantes) was used to calibrate the spectrometer over the examined spectral range. RESULTS Micro- and nanomorphology - The wing scales of all the species we investigated show qualitatively the same micro- and nanostructures discussed as Uraniatype with pepper-pot structures of ELIOT (1973) and TlLLEY & ELIOT (2002). These 3D structures were classified as Type III Scale by VUKUSIC et al. (2000) stressing that these type of structures display physical colouration that does not arise from multi-layering but from scattering within and on the body of the scale. The measurements we carried out on the LR and the CR reveal that all the taxa investigated are in the same nano domain but differing in quantitative terms (PARKER 2006). The 3D lattices reveal quantitative and qualitative differences (Table 1).