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)

causes a basic effect in the ecology of polyommatine lycaenid butterflies: generally patrolling and perching blue males in discoloured state becomes sedentary and territorial, and their population density turns to be higher with one magnitude (BÁLINT, unpublished data collected in situ in the case of Polyommatus admetus (ESPER, 1789) and P. thersites (CANTENER, 1834)). Consequently we regard scale micro- and nanostructures to be important factors in how the species and its lineage (species group or genus) fits in time and space, prior to any phenomena including sexual interaction (BÁLINT, VÉRTESY & BlRÓ 2005, BÁLINT, KERTÉSZ, VÉRTESY & BÍRÓ 2005 and LUKHTANOV et al 2005). PBG 3D "pepper-pot" lattices are complex structures. Their development should have been a "cost"-intensive task. Published results, which are in accordance with our observations based on more than 70 investigated lycaenid species from all the subfamilies, suggest that micro- and nanostructures are rather constant in closely related species or genera (TlLLEY & ELIOT 2002). Therefore we hypothesise that: (1) allopatric species of a given monophyletic group (with immediate common hypothetical ancestor) possess qualitatively identical optical properties, but they may differ quantitatively as they have a relatively close or immediate common ancestor. Therefore they generate similar colour but always with different hue; (2) lineages branched off but still in the same monophyly (species groups or genera) possess qualitatively different optical characteristics, as their do not share an immediate common ancestor in their lineage. The present paper is addressed to test these two hypotheses by describing and analysing the PBG scale micro- and nanostructures of the target taxa using Scanning Electron Microscopy (SEM) and by measuring the reflectance of the PBG generated colours using experimental spectroscopic techniques. MATERIALS AND METHODS Our target organisms were certain endemic taxa of the P. eros species group {sensu BÁLINT & JOHNSON, 1997) of the Old World genus Polyommatus LATREILLE, 1804 (type species: Papilio icarus DENIS et SCHIFFERMÜLLER, 1775). We investigated three representatives of the group, all isolated from each other. They inhabit tundral or oreal steppes (1) in the Alps: P. eros (OCHSENHEIMER, 1808) (Figs 3-4), (2) in the Balkans: P. eroides (FRIVALDSZKY, 1835) (Figs 5-6) and (3) in the Altai regions: P. erotides (STAUDINGER, 1894) (Figs 7-8). As an outgroup, for testing the second hypothesis, we selected two congeneric taxa,