Search Results (6)

Coxal combs, found only in members of the ‘cydnoid’ complex (comprising four families: Cydnidae, Parastrachiidae, Thaumastellidae, and Thyreocoridae) within the superfamily Pentatomoidea, have long been regarded as a character confirming their close evolutionary relationship. However, many studies have demonstrated that these four families are phylogenetically distant. Others have been treated as subfamilies of the broadly defined Cydnidae, with the coxal combs as the only character linking them. This is the first study on the origin of coxal combs in species of all families and subfamilies that represent the broadly conceived Cydnidae (69 species in 39 genera). Moreover, this study presents the first 16S rDNA gene sequences providing a basis for such analyses. The analyses included DNA sequences of 62 species in 34 genera of Cydnidae sensu stricto, three species in two genera of Thyreocoridae, two species in two genera of Parastrachiidae, and two species in one genus of Thaumastellidae. The sequence analysis in the family Cydnidae covered 35 species representing 19 genera of the subfamily Cydninae, 16 species in eight genera of the subfamily Sehirinae, five species in two genera of Amnestinae, three species in three genera of Garsauriinae, two species in one genus of Cephalocteinae, and one species of Amaurocorinae. The results of our study demonstrate the independent origin of coxal combs in taxa of the ‘cydnoid’ complex within the superfamily Pentatomoidea. They confirm the polyphyly not only of the entire ‘cydnoid’ complex but also of the family Cydnidae itself. Full article

The SSU nuclear rDNA (encoding 18S ribosomal RNA) is one of the most frequently sequenced genes in the molecular analysis of insects. Molecular apomorphies in the secondary and tertiary structures of several 18S rRNA length-variable regions (LVRs) located within the V2, V4, and V7 hypervariable regions can be good indicators for recovering monophyletic groups within some heteropteran families. Among the LVRs that have been analysed, the LVR L in the V4 hypervariable region is the longest and most crucial for such assessments. We analysed the 18S rRNA V4 hypervariable region sequences of 45 species from the family Cydnidae, including all 6 subfamilies (Amaurocorinae, Amnestinae, Cephalocteinae, Cydninae, Garsauriinae, and Sehirinae) and three pentatomoid families (Parastrachiidae, Thaumastellidae, and Thyreocoridae), which have often been included in the broadly defined Cydnidae family. This is the first time that representatives of all Cydnidae subfamilies have been included in a molecular analysis. Only taxa from two subfamilies, Sehirinae and Cydninae, have been used in previous molecular studies. The secondary and tertiary structures of the LVR L were predicted for each species using the two-step procedure already accepted for such analyses to recover any molecular apomorphy essential for determining monophyly. The results of our comparative studies contradict the current understanding of the relationships among burrowing bugs and the current family classification. Full article

The SSU nrDNA, a small subunit of the nuclear ribosomal DNA (coding 18S rRNA), is one of the most frequently sequenced genes in molecular studies in Hexapoda. In insects, including true bugs (Hemiptera: Heteroptera), only its primary structures (i.e., aligned sequences) are predominantly used in phylogenetic reconstructions. It is known that including RNA secondary structures in the alignment procedure is essential for improving accuracy and robustness in phylogenetic tree reconstruction. Moreover, local plasticity in rRNAs might impact their tertiary structures and corresponding functions. To determine the systematic position of Thaumastellidae within the superfamily Pentatomoidea, the secondary and—for the first time among all Hexapoda—tertiary structures of 18S rRNAs in twelve pentatomoid families were compared and analysed. Results indicate that the shapes of the secondary and tertiary structures of the length-variable regions (LVRs) in the 18S rRNA are phylogenetically highly informative. Based on these results, it is suggested that the Thaumastellidae is maintained as an independent family within the superfamily Pentatomoidea, rather than as a part of the family Cydnidae. Moreover, the analyses indicate a close relationship between Sehirinae and Parastrachiidae, expressed in morpho-molecular synapomorphies in the predicted secondary and tertiary structures of the length-variable region L (LVR L). Full article

The fossil burrower bug Eocenocydnus lisi described from the Late Eocene of the Isle of Wight, UK, is analysed using a parallel, cross-eyed viewing method. The species, tentatively placed in the subfamily Sehirinae, is redescribed and its systematic position is discussed. Newly recovered morphological characteristics allow it to be placed in the tribe Cydnini of the subfamily Cydninae. Full article

Eight species of the superfamily Pentatomoidea are recorded from Greece for the first time: Aelia germari Küster 1852, Eurygaster hottentotta (Fabricius 1775), Eysarcoris aeneus (Scopoli 1763), Neottiglossa lineolata (Herrich-Schaeffer 1830), Neottiglossa pusilla (Gallen 1789), Picromerus bidens (Linnaeus 1758), Podops (Podops) inunctus (Fabricius 1775) and Tarisa pallescens (Jakovlev 1871). A complete updated species checklist with distributional data notes for all the new species for Greece are provided. Full article

Pentatomoidea is the largest superfamily of Pentatomomorpha; however, the phylogenetic relationships among pentatomoid families have been debated for a long time. In the present study, we gathered the mitogenomes of 55 species from eight common families (Acanthosomatidae, Cydnidae, Dinidoridae, Scutelleridae, Tessaratomidae, Plataspidae, Urostylididae and Pentatomidae), including 20 newly sequenced mitogenomes, and conducted comparative mitogenomic studies with an emphasis on the structures of non-coding regions. Heterogeneity in the base composition, and contrasting evolutionary rates were encountered among the mitogenomes in Pentatomoidea, especially in Urostylididae, which may lead to unstable phylogenetic topologies. When the family Urostylididae is excluded in taxa sampling or the third codon positions of protein coding genes are removed, phylogenetic analyses under site-homogenous models could provide more stable tree topologies. However, the relationships between families remained the same in all PhyloBayes analyses under the site-heterogeneous mixture model CAT + GTR with different datasets and were recovered as (Cydnidae + (((Tessaratomidae + Dinidoridae) + (Plataspidae + Scutelleridae)) + ((Acanthosomatidae + Urostylididae) + Pentatomidae)))). Our study showed that data optimizing strategies after heterogeneity assessments based on denser sampling and the use of site-heterogeneous mixture models are essential for further analysis of the phylogenetic relationships of Pentatomoidea. Full article