The presented thesis deals with the intraspecific variability of flower beetles species complex Potosia cuprea (Fabricius, 1795), which is a complex of taxa at the species and subspecies level. Flower beetles from species complex Potosia cuprea are among the most variable Palaearctic Cetoniinae at all. Taxa included in the complex produces chromatic range varieties which were, and still are, perceived differently by different authors. Taxa included in the analyses come primarily from western Palaearctic region, with the main emphasis on European species and subspecies. The aim of this work is the use of molecular genetics methods to verify the justification of their species or subspecies level. At all, there were obtained sequences for two mitochondrial genes (cytochrome b and cytochrome oxidase I) from 14 taxa species complex Potosia cuprea and three related species P. angustata (Germar, 1817), P. fieberi (Kraatz, 1931) and P. marginicollis (Ballion, 1870). Molecular analyzes based on COI dataset and concatenate of CytB and COI revealed the existence of a "European" clade P. cuprea, which includes subspecies: Potosia cuprea bourgini (Ruter, 1967), P. c. brancoi (Barraud, 1992), P. c. cuprea (Fabricius, 1775), P. c. metallica (Herbst, 1790) a P. c. obscura (Mikšić, 1954), to which also fit two...

The aim of the work presented in this thesis is to contribute to a fundamental understanding of polarizing phenomena in some scarab beetles. The aim is also to study the beetle structures as inspiration in fabrication of artificially sculptured films. The three investigated species Cetonia aurata, Potosia cuprea and Liocola marmorata are of the family Scarabaediae and subfamily Cetoniianae (Guldbaggar). They were all collected at Swedish locations and are the only species of Cetoniinae scarabs in Sweden. This work reports on their optical properties represented by Mueller matrix elements, degree of polarization data and trace curves in the Cartesian complex plane representation of polarized light. From these results we verifyan earlier structural model for the Cetonia aurata and make way for similar models of the other two species. The ellipsometer used in this work is of dual rotating compensator type from which the complete Mueller-matrix for the medium examined can be obtained. The ellipsometric measurements were conducted on the scutellum for four different angles of incidence, 45°, 55°, 65° and 75° over a wave-length range of 245-1000 nm. Common for all examined species is that left polarization is observed in the wavelength range of 400 800 nm. For most of these species the polarization state is close to circular at some wavelengths especially at smaller angles of incidence. In general the degree of polarization is high (above 50%) when the polarization is near-circular. The degree of polarization also shows a clear dependence on the angle of incidence. The earlier model for Cetonia aurata shows a good agreement with the experimental data of this work. The model is also found as a good basis to work from to create models for the other two species.