@article {13235,
	title = {Genetic distinctness of parthenogenetic forms of European Polydrusus weevils of the subgenus Scythodrusus},
	journal = {Insect Science},
	volume = {19},
	number = {2},
	year = {2012},
	month = {April},
	pages = {183-194},
	abstract = {Among eight species of Polydrusus weevils which belong to subgenus Scythodrusus, at least two possess parthenogenetic forms: P. (S.) inustus and P. (S.) pilifer. Both of these species consist of dioecious populations in the Caspian area and of parthenogenetic populations in Eastern Europe (P. (S.) inustus), the Caucasus region (both species) and Middle Asia (P. (S.) pilifer). The origin of parthenogenesis in this subgenus is unresolved; however some data suggest that the parthenogenetic forms are of hybrid ancestry. The genetic distinctness of parthenogenetic Scythodrusus was assessed on the basis of COII, ITS2, EF1-[alpha] and Wolbachia wsp, 16S ribosomal DNA, ftsZ and hcpA sequence comparisons. Both taxa turned out to be monophyletic for all markers, which is an evidence against hybridization of their dioecious ancestors. On the other hand, a high frequency of heterozygous P. (S.) inustus females suggests an origin resulting from hybridization between genetically distinct dioecious representatives of this species. Very similar strains of Wolbachia supergroup A were found in both species, indicating that they have been either inherited from a common ancestor or were transmitted between parthenogenetic Scythodrusus weevils and probably spread randomly across their ranges.},
	keywords = {Polydrusus, Scythodrusus},
	isbn = {1672-9609},
	author = {Kajtoch, Lukasz and Korotyaev, Boris and Lachowska-Cierlik, Dorota}
}
@article {13236,
	title = {Genetic constitution of parthenogenetic form of Polydrusus inustus (Coleoptera: Curculionidae) - hints of hybrid origin and recombinations},
	journal = {Folia Biologica (Cracow)},
	volume = {57},
	number = {3-4},
	year = {2009},
	month = {2009},
	pages = {149-156},
	abstract = {Asexual reproduction among insects may arise spontaneously, as a result of infectious agents or hybridization between phylogenetically distinct organisms. Polyploidy, which may be the result of auto- or allopoliploidization (also associated with hybridization), is often connected with parthenogenesis. However, all studied parthenogens of weevils were apomietic, rare meiotic stages have been observed in a few of them what could Suggests in their genomes besides file Mutational changeability also recombination may occurs. We Studied the level of heterozygosity in Internal Transcribed Spacer 2 sequences, and congruence of mitochondrial (cytochrome B) and nuclear genealogies among individuals of parthenogenetic form of Polydrusus inustus. High frequency (87.0\%) of heterozygotes in ITS2 sequences may indicate a hybrid origin of the parthenogen. It is possible that this parthenogenetic form arose via a hybridization event between phylogenetically distinct lineages of bisexual P. inustus, known only from Georgia and Turkey, or between this species and one of the closely relatives from file subgenus Scythodrusus, Although result of partition-homogeneity test did not show significant incongruence of mitochondrial and nuclear genealogies, in the network was detected one loop. Most probable explanations for existence of that loop in parthenogenetic form and for origin of rare homozygotes, which were detected in ITS2 sequences, is gene conversion. It is supported by recently cytogenetic studies indicating rare meiotic stages during the oogenesis of triploids of P. inustus.},
	keywords = {Polydrusus},
	isbn = {0015-5497},
	author = {Kajtoch, Lukasz and Lachowska-Cierlik, Dorota}
}
@article {13237,
	title = {Genetic diversity of the xerothermic weevils Polydrusus inustus and Centricnemus leucogrammus (Coleoptera: Curculionidae) in central Europe},
	journal = {European Journal of Entomology},
	volume = {106},
	number = {3},
	year = {2009},
	month = {2009},
	pages = {325-334},
	abstract = {Phylogeography, genetic diversity, and demography of central European populations of two flightless xerothermic weevils, Polydrusus inustus and Centricnemus leucogrammus, were studied based on the polymorphism of three mtDNA genes (COII, CytB, and ND1). Results indicate that these xerothermic beetles may have different origins. P. inustus is a recent migrant as the parthenogenetic form has a low level of genetic diversity and lacks a geographic population structure. This is probably a result of a recent (before the end of last glaciation) expansion and/or present dispersal mediated by humans. On the other hand, C. leucogrammus appears to be a relic species as the populations of this species are much more genetically diverse (six distinct clades) and some of the populations are allopatric and others sympatric. They probably diverged and expanded during the last few glaciations. Genetic discontinuities were detected among localities that are now separated by gaps in the distribution. Boundaries (mountains or farmland) separate the populations into three groups: (1) Moravia and Slovakia, (2) the lower Vistula Valley in northern Poland and (3) south-eastern Poland together with western Ukraine. Evidence for recent gene flow was found only among populations from south-eastern Poland and western Ukraine, and between these two groups. One population from northern Poland was surprisingly related to populations in southern Poland, which may be due to extinction of intermediate populations.},
	keywords = {Centricnemus leucogrammus, Polydrusus, Polydrusus inustus},
	isbn = {1210-5759},
	author = {Kajtoch, Lukasz and Lachowska-Cierlik, Dorota and Mazur, Mieczyslaw}
}
