Takecallis nigroantennatus Wieczorek sp. nov. (Hemiptera: Aphididae), associated with the cold hardy bamboo variety Fargesia spp. (Bambusoideae), is described and illustrated along with a key to species of the genus Takecallis. The results of a mitochondrial COI (DNA barcoding) and nuclear elongation factor 1 (EF1α) gene sequences, which confirm the genetic difference of the new taxon from the other congeneric species, are provided. The possible way of introduction of this species to Europe is discussed with its new locality from Belgium.

Species (or cryptic species) identification in microbial eukaryotes often requires a combined morphological and molecular approach, and if possible, mating reaction tests that confirm, for example, that distant populations are in fact one species. We used P. biaurelia (one of the 15 cryptic species of the P. aurelia complex) collected worldwide from 92 sampling points over 62 years and analyzed with the three above mentioned approaches as a model for testing protistan biogeography hypotheses. Our results indicated that despite the large distance between them, most of the studied populations of P. biaurelia do not differ from each other (rDNA fragment), or differ only slightly (COI mtDNA fragment). These results could suggest that in the past, the predecessors of the present P. biaurelia population experienced a bottleneck event, and that its current distribution is the result of recent dispersal by natural or anthropogenic factors. Another possible explanation for the low level of genetic diversity despite the huge distances between the collecting sites could be a slow rate of mutation of the studied DNA fragments, as has been found in some other species of the P. aurelia complex. COI haplotypes determined from samples obtained during field research conducted in 2015–2016 in 28 locations/374 sampling points in southern Poland were shared with other, often distant P. biaurelia populations. In the Kraków area, we found 5 of the 11 currently known COI P. biaurelia haplotypes. In 5 of 7 reservoirs from which P. biaurelia was obtained, two different COI haplotypes were identified.

SAWKA N. 2012. Mating types in Paramecium and a molecular approach to their determination. Folia biologica (Krakow) 60: 3-9. Mating types are expressed in ciliates for the duration of the mature period of their clonal cycle. During cell conjugation the reciprocal fertilization of complementary mating types takes place. Models of mating type determination in the Paramecium aurelia species complex based on classical genetics are reviewed including molecular aspects of the studies.