Załącznik online: Macierzpdystansu dla haplotypów porównywanych parami zidentyfikowanych dla łączonego zestawienia markerów mitochondrialnych (COI +16S) analizowanych w populacjachI. cimicoides. Wartości dystansu oznaczono poniżej przekątnej, a powyżej - wartości odchylenia standardowego.

Genetic diversity of populations is shaped by several phenomena, including mutations, genetic drift, natural selection and migration. The presence of bacterial endosymbionts may also influence mitochondrial DNA variability in host species. In addition, historical events, such as Pleistocene glaciations, play a significant role in the observed pattern of diversity. Molecular markers are often used in studies of genetic variability and analyses of population demographic structure. The species studied in this work is the saucer bug, belonging to infraorder Nepomorpha (Hemiptera: Heteroptera). Six populations inhabiting water reservoirs in Poland and Bulgaria were selected for analysis. The aim of the study was estimation of genetic variability and analyze demographic changes in selected populations of <i>Ilyocoris cimicoides</i>. The research was based on the assessment of molecular variability of mitochondrial (COI, 16S) and nuclear (EF-1α) markers. In addition, molecular detection of the endosymbiotic bacteria <i>Wolbachia</i> was performed based on amplification of a fragment of the <i>wsp</i> gene, and the absence of the endosymbiotic bacteria in selected populations of <i>I. cimicoides</i> was demonstrated. The results obtained during the study indicate a moderate degree of genetic diversity between the analysed populations. Despite the large geographical distance and limited mobility of the species, no clear isolation due to distance between the studied individuals was observed. Neutrality tests and analysis of the mismatch distribution indicate a recent expansion in the studied populations. Further research based on additional statistical and phylogenetic analyses, including a larger number of specimens from a wider geographical range is needed. This will allow for a more accurate explanation of the observed pattern of phylogenetic relationships within the studied species and to place the signs of expansion demonstrated in this study in time.