The Chromosomes of three species of the Nasonia complex (Hymenoptera, Pteromalidae).

Die Ergebnisse der Untersuchung des Karyotyps der Schwesterarten Nasonia vitripennis (Walker, 1836), N. longicornis Darling, 1990 und N. giraulti Darling, 1990 werden mitgeteilt. Für die beiden letztgenannten Arten liegen bisher keine karyologischen Daten vor. Die Karyotypen der drei untersuchten Arten mit n=5 und 2n=10 bestehen aus metacentrischen Chromosomen. Die Verteilung des konstitutiven Chromatins scheint in der Gattung Nasonia Ashmead, 1904 ebenfalls sehr einheitlich zu sein. Demgegenüber ergab die Morphometrie der Chromosomen statistisch signifikante Unterschiede zwischen den drei Arten. Die vorliegenden Daten entsprechen der Abfolge der Artenspaltungen im Nasonia-Komplex, die auf der Basis molekulargenetischer Untersuchungen festgestellt wurde.The karyotypes of three sibling species, Nasonia vitripennis (Walker, 1836), N. longicornis Darling, 1990 and N. giraulti Darling, 1990 were examined, the latter two species for the first time. All species have chromosome numbers of n=5 and 2n=10, their chromosomes being metacentric. The distribution of constitutive heterochromatin also appears to be similar in the genus Nasonia Ashmead, 1904. However, statistical karyotypic differences between studied species were revealed using chromosome morphometrics. These data are consistent with the order of divergence in the Nasonia complex found on the basis of molecular studies

Chromosomes of Aphidius ervi Haliday, 1834 (Hymenoptera: Braconidae).

Die Chromosomenanalyse einiger Laborlinien von Aphidius ervi Haliday, 1834 aus Deutschland ergab n=5 und 2n=10. Allerdings wurden bei einigen weiblichen Tieren einer Population Chromosomensätze mit 2n=12 gefunden. Diese Tiere repräsentieren wahrscheinlich eine thelythoke Linie, die aus einer ursprünglich arrhenotoken Population hervorging. Der Karyotyp mit 2n=12 enthält ein zusätzliches charakteristisches Paar vollständig heterochromatischer akrozentrischer Chromosomen.StichwörterChromosomes, Aphidius ervi, Hymenoptera, Braconidae.Chromosome numbers of n=5 and 2n=10 were found in a few laboratory strains of Aphidius ervi Haliday, 1834 from Germany. However, several females having 2n=12 were detected in one of the populations studied. These females are likely to represent a thelytokous strain originating from an initially arrhenotokous one. The karyotype with 2n=12 has a characteristic additional pair of fully heterochromatic acrocentric chromosomes.KeywordsChromosomes, Aphidius ervi, Hymenoptera, Braconidae

Chromosomes of the genus Arge Schrank, 1802 (Hymenoptera, Argidae): new data and review

Results of the chromosome study of 12 sawfly species of the genus Arge Schrank, 1802 are reviewed, including new data on the karyotypes of A. ciliaris (Linnaeus, 1767) and A. enodis (Linnaeus, 1767) with n = 10. Moreover, the same chromosome number, n = 10, is found in A. ustulata (Linnaeus, 1758), for which n = 8 was previously reported. In addition, n = 8 is confirmed in A. gracilicornis (Klug, 1814). The results of the morphometric analysis of chromosome sets of these four species are given. In the genus Arge, haploid chromosome numbers of n = 8, 10, 11 and 13 were found. Among these sawflies, n = 8 appeared to be the most frequent chromosome number, followed by n = 10. The known data of the chromosome study of these insects are summarized and discussed in the light of phylogeny and taxonomy of the genus Arge

Genomic and karyotypic variation in Drosophila parasitoids (Hymenoptera, Cynipoidea, Figitidae)

Abstract Drosophila melanogaster Meigen, 1830 has served as a model insect for over a century. Sequencing of the 11 additional Drosophila Fallen, 1823 species marks substantial progress in comparative genomics of this genus. By comparison, practically nothing is known about the genome size or genome sequences of parasitic wasps of Drosophila. Here, we present the first comparative analysis of genome size and karyotype structures of Drosophila parasitoids of the Leptopilina Förster, 1869 and Ganaspis Förster, 1869 species. The gametic genome size of Ganaspis xanthopoda (Ashmead, 1896) is larger than those of the three Leptopilina species studied. The genome sizes of all parasitic wasps studied here are also larger than those known for all Drosophila species. Surprisingly, genome sizes of these Drosophila parasitoids exceed the average value known for all previously studied Hymenoptera. The haploid chromosome number of both Leptopilina heterotoma (Thomson, 1862) and Leptopilina victoriae Nordlander, 1980 is ten. A chromosomal fusion appears to have produced a distinct karyotype for Leptopilina boulardi (Barbotin, Carton et Keiner-Pillault, 1979)(n = 9), whose genome size is smaller than that of wasps of the Leptopilina heterotoma clade. Like Leptopilina boulardi, the haploid chromosome number for Ganaspis xanthopoda is also nine. Our studies reveal a positive, but non linear, correlation between the genome size and total chromosome length in Drosophila parasitoids. These Drosophila parasitoids differ widely in their host range, and utilize different infection strategies to overcome host defense. Their comparative genomics, in relation to their exceptionally well-characterized hosts, will prove to be valuable for understanding the molecular basis of the host-parasite arms race and how such mechanisms shape the genetic structures of insectcommunities

The last twenty years of parasitic Hymenoptera karyology: an update and phylogenetic implications

Volume: 4Start Page: 41End Page: 6

Chromosomes of Blastophaga psenes (Hymenoptera: Agaonidae)

Volume: 19Start Page: 187End Page: 18

Chromosomes of Belonocnema treatae Mayr, 1881 (Hymenoptera, Cynipidae)

Chromosomes of the asexual and sexual generation of the gall wasp Belonocnema treatae Mayr, 1881 (Cynipidae) were analyzed. Females of both generations have 2n = 20, whereas males of the sexual generation have n = 10. Cyclical deuterotoky is therefore confirmed in this species. All chromosomes are acrocentric and form a continuous gradation in size. This karyotype structure is probably ancestral for many gall wasps and perhaps for the family Cynipidae in general. Chromosome no. 7 carries a characteristic achromatic gap that appears to represent a nucleolus organizing region

Morphometric analysis and taxonomic revision of <em>Anisopteromalus</em> Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) - an integrative approach.

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Data from: Morphometric analysis and taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) – an integrative approach

We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of species) and all available published data on morphology, karyology, behavior, host associations, and geographic distribution. We demonstrate that the analysis of quantitative characters using MRA plays a major role for the integration of name-bearing types and thus for the association of taxa with names. Six species are recognized, of which two are new: A. cornis Baur sp. n. and A. quinarius Gokhman & Baur sp. n. For Anisopteromalus calandrae (Howard), a well-known, cosmopolitan parasitoid of stored-product pests, we have selected a neotype to foster continuity and stability in the application of this important name. The species was sometimes confused with the related A. quinarius sp. n., another cosmopolitan species that is frequently encountered in similar environments. We also show that several species originally described or later put under Anisopteromalus actually belong to different genera: Cyrtoptyx camerunus (Risbec) comb. n.; Meraporus glaber (Szelényi) comb. n.; Dinarmus schwenkei (Roomi, Khan & Khan) comb. n. Neocatolaccus indicus Ayyar & Mani is confirmed as a junior synonym of Oxysychus sphenopterae (Ferrière) syn. n. and Anisopteromalus calandrae brasiliensis (Domenichini) stat. rev. must be considered as a valid but doubtful taxon

Data from: Morphometric analysis and taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) – an integrative approach

We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of species) and all available published data on morphology, karyology, behavior, host associations, and geographic distribution. We demonstrate that the analysis of quantitative characters using MRA plays a major role for the integration of name-bearing types and thus for the association of taxa with names. Six species are recognized, of which two are new: A. cornis Baur sp. n. and A. quinarius Gokhman & Baur sp. n. For Anisopteromalus calandrae (Howard), a well-known, cosmopolitan parasitoid of stored-product pests, we have selected a neotype to foster continuity and stability in the application of this important name. The species was sometimes confused with the related A. quinarius sp. n., another cosmopolitan species that is frequently encountered in similar environments. We also show that several species originally described or later put under Anisopteromalus actually belong to different genera: Cyrtoptyx camerunus (Risbec) comb. n.; Meraporus glaber (Szelényi) comb. n.; Dinarmus schwenkei (Roomi, Khan & Khan) comb. n. Neocatolaccus indicus Ayyar & Mani is confirmed as a junior synonym of Oxysychus sphenopterae (Ferrière) syn. n. and Anisopteromalus calandrae brasiliensis (Domenichini) stat. rev. must be considered as a valid but doubtful taxon