Divergence time analysis of the Neotropical wasp genus Protopolybia Ducke, 1905 (Vespidae, Polistinae, Epiponini) using a Multilocus Phylogenetic Approach.

The genus Protopolybia Ducke was analyzed using a multilocus phylogenetic approach, which confirmed its monophyly. In contrast with the arrangements derived solely from morphological data, however, this analysis divides the genus into only two major clades. The study also presents divergence times for the origin and diversification of Protopolybia, which are related to possible vicariant events occurring in the Amazon biome.

Rediscovery of the social wasp Mischocyttarus (Kappa) tapuya Schulz, with description of the female, larva and nest (Vespidae, Polistinae).

Mischocyttarus tapuya was originally described from a single male specimen collected in a forest near Belm, state of Par, Brazil, in the year of 1893, and had never been found again. We recently collected a colony of this species in an urban forest locality near Belm, and here describe the previously unknown female, mature larva, and nest of this social wasp.

Taxonomic revision of the P. chartergoides species-group of the genus Protopolybia Ducke, 1905 (Hymenoptera: Vespidae, Polistinae).

A taxonomic revision of the Protopolybia chartergoides species-group was undertaken. Protopolybia isthmensis (Richards) stat. nov. is elevated to the level of species. The male genitalia of P. chartergoides (Gribodo), P. fuscata (Fox), and P. pallidibalteatus (Cameron) are illustrated and described. New collection records and new identification keys are presented for the species groups of Protopolybia, and the species within the P. chartergoides species-group.

Taxonomic revision of the Protopolybia picteti-emortualis species-group (Richards, 1978), with descriptions of two new species (Hymenoptera: Vespidae, Polistinae).

A taxonomic revision of the Protopolybia picteti-emortualis species-group now demonstrates that this group is possibly the largest in Protopolybia, comprising 15 species: P. eldinaris sp. nov.; P. djaneteae sp. nov.; P. cameranii (Zavattari 1906) = P. bella (Von Ihering 1903) syn. nov.; P. fulvotincta stat. rev.; P. biguttata, P. nitida, P. alvarengai, P. iheringi, P. perfulvula, P. steinbachi, P. wheeleri, P. rotundata, P. picteti, P. emortualis and P. duckei. Male and female genitalia are illustrated for P. biguttata Bequaert, P. bella, P. nitida, P. fulvotincta and P. picteti. New collection records and a new identification key are presented for this species-group.

Update to the knowledge of the social wasps of the Brazilian state of Amapá based on the vespid collection of the Amapá Research Institute (IEPA) (Hymenoptera, Vespidae, Polistinae).

Information is presented concerning specimen records of polistine social wasps in the state of Amapá, Brazil, in the years from 1904 to 2016, mainly coming from the IEPA and MPEG collections. Spatial distribution of records and of the total collecting effort were analyzed with respect to general landscape aspects of the region, such as vegetation types, hydrography, road infrastructure and the state network of conservation unities. The number of social wasp species registered for Amapá is now 144, with 17 new records of species for the Guiana Shield, and nine species not yet described. Seventeen genera are known to occur in the region, with Mischocyttarus de Saussure and Polybia Lepeletier being richer in species.

Revision of the species-group of Mischocyttarus (Omega) filiformis (de Saussure 1854), with description of three new species (Hymenoptera, Vespidae).

A taxonomic revision of the species-group related to M. filiformis (Saussure 1854) is presented along with an identification key to species. After Richards (1978) and following the rearrangement of the subgenus Omega de Saussure by Silveira (2008), the species-group considered herein included three species in addition to M. filiformis; i.e. M. buyssoni (Ducke 1906), M. napoensis Richards 1978 and M. omicron Richards 1978.  In the present work, three new species are added: M. nazgul sp. nov.; M. asahi sp. nov.; M. kallindusfloren sp. nov.; the male of M. filiformis is also described here in detail for the first time, and new distributional records are provided for the included species.

Interplay between magnetic, metal/insulator and topological phases in Hg1-x Mn x Te alloys: prediction of a ferromagnetic Weyl semimetal at x = 0.25.

We report a theoretical investigation of magnetic, electronic, and topological properties of Hg1-x Mn x Te alloys. We consider periodic structures with Mn concentrations as x = 0, 0.25, 0.5, 0.75, and 1. Our hybrid DFT/Hartree-Fock calculations for the bandgaps of antiferromagnetic (ground-state) phases are in good agreement with experiments. The calculations also show that the modification of the magnetic ordering from anti- to ferromagnetic leads to a significant bandgap reduction, resulting in a metal/insulator transition at higher Mn concentrations. We show that a ferromagnetic Weyl semimetal phase is achieved for x = 0.25, where a single pair of Weyl nodes mirrored by the [Formula: see text] point in the momentum space is observed. The non-trivial topological property of the ferromagnetic Hg0.75Mn0.25Te is confirmed by the calculation of the chirality of each Weyl node, which are connected by a surface Fermi arc of a semi infinite Hg0.75Mn0.25Te.

Taxonomic notes on social wasps of the groups of Mischocyttarus wagneri (Buysson 1908) and M. barbatus Richards 1945 (Hymenoptera, Vespidae, Polistinae)

ABSTRACT Taxonomic revisionary notes and identification keys are presented for two species-groups of wasps of the genus Mischocyttarus, subgenus Phi. Material of the M. wagneri and M. barbatus groups, including types, was examined in several collections, resulting in description of one new species for the first mentioned group (M. camanducaia sp. nov.), and several new synonymies for both groups as follows (senior synonym in bold): [Mischocyttarus mourei Zikán 1949 = Mischocyttarus laneiZikán 1949 = Mischocyttarus plaumanniZikán 1949]; [Mischocyttarus declaratusZikán 1935 = Mischocyttarus confirmatusZikán 1935 = Mischocyttarus brackmanniZikán 1949 = Mischocyttarus alternatusZikán 1949 = Mischocyttarus cabaunaZikán 1949]; [Mischocyttarus barbatus Richards 1945 = Mischocyttarus ecuadorensisZikán 1949 = Mischocyttarus pedunculariusZikán 1949]. In addition, several cases are demonstrated of changing in group content, with species being moved into and out of groups as required. Both groups are distributed on the highlands of Central and South America, with the M. wagneri group being endemic to southeastern areas of the continent.

Notes on the nest of the social wasp Pseudopolybia langi (Hym., Vespidae, Polistinae)

Abstract Detailed descriptions of the architecture of Pseudopolybia langi nests are presented for the first time. Structural variations in the arrangements of nest parts are described and compared with features observed in other species of Pseudopolybia and other epiponine genera.

Taxonomic revision of the Protopolybia sedula species-group (Hymenoptera, Vespidae, Polistinae), with an new identification key to species.

A taxonomic review of the P. sedula species-group is presented. New diagnostic characters are described and all species redescribed. The male genitalia of P. sedula (de Saussure) and P. weyrauchi Bequaert are described and drawn. New collection records and a new identification key for the species-group are given.

Bilayers of Ni3C12S12 and Pt3C12S12: graphene-like 2D topological insulators tunable by electric fields.

In the present work we predict, through first-principles calculations, that bilayers of the recently synthesized Ni3 [Formula: see text] [Formula: see text] and Pt3 [Formula: see text] [Formula: see text] layered materials are topological insulators upon electron doping, and that their topological insulator properties can be modulated by the application of electric fields with magnitudes achievable in devices. The electronic structures of both bilayers are characterized by spin-orbit split graphene-like bands, with gap magnitudes that are three orders of magnitude larger than graphene's. In ribbon geometries, chiral edge modes develop at each side with band dispersions similar to that of Kane-Mele graphene model. Surprisingly, the edge states' spin-propagation locking occurs even for very thin ribbons. We also find that the response of the electronic structure of both materials to applied electric fields are similar to both graphene and the Kane-Mele model with a Rashba term. All these findings indicate that these bilayer systems can be considered as large-spin-orbit graphene analogues with a strong sensitivity to applied electric fields.

Electronic and spin-orbit properties of the kagome MOF family M3(1,2,5,6,9, 10-triphenylenehexathiol)2 (M = Ni, Pt, Cu and Au).

We investigate, through first-principles calculations, the electronic band structure-including the spin-orbit coupling-of single-layer M3(THT)2 metal-organic frameworks, where M = Ni, Pt, Cu and Au, and THT is the 1,2,5,6,9,10-triphenylenehexathiol molecule. This MOF family contains, in its electronic structure, spin-orbit gaps that could allow their use in quantum spin Hall effect devices. We find that the partial inclusion of exact exchange in the calculations (beyond a semi-local exchange-correlation level) leads to quantitative, and even qualitative, modifications of the electronic structure of Ni3(THT)2 and Pt3(THT)2 relative to calculations at semi-local exchange-correlation level: upon inclusion of exact exchange, the predicted fundamental band gap of these semiconductor materials increases to more than twice, and the predicted spin-orbit gaps change by as much as 44%. Even the qualitative description of the valence bands of these materials changes upon inclusion of exact exchange. We also find that the magnitudes of the spin-orbit gaps are not monotonic with the atomic number of the metal atom.

Nectarinella manauara, new species and record of the genus from Brazilian Amazonia (Hymenoptera, Vespidae, Polistinae)

ABSTRACT Nectarinella manaura sp. nov. is described, representing the first record of the genus from Brazilian Amazonia. Its description raises richness for Nectarinella from two to three species, and extends the range of characteristics for the genus, especially in terms of body size and color patterns. Discovery of the new species may shed new light into the knowledge of phylogenetic relationships between Nectarinella and other closely related genera.

Vibrational corrections to the second hyperpolarizabilities of Al(n)P(n) clusters.

In this work, we report results of vibrational corrections to the second hyperpolarizabilities of Al2P2, Al3P3, Al4P4, Al6P6, and Al9P9 clusters. The vibrational corrections were calculated through the perturbation theoretic method of Bishop and Kirtman and also using a variational methodology at the second order Møller-Plesset perturbation theory level with the aug-cc-pVDZ basis set. Results show that the vibrational corrections are important, accounting for more than half of the corresponding electronic second hyperpolarizabilities at the static limit. Comparisons between results obtained through both methods show very good agreements for the terms [α(2)] and [µß] but significant differences for the term [µ(2)α]. Dynamic vibrational corrections to the second hyperpolarizabilities related to the dc-second harmonic generation, intensity dependent refractive index, and dc-Kerr nonlinear optical processes are also reported.

Notes on social wasps of the group of Mischocyttarus(Omega) punctatus (Ducke), with description of six new species (Hymenoptera, Vespidae, Polistinae)

ABSTRACTA revision of the taxonomic status and an identification key for wasp species of the genus Mischocyttarus related to M. punctatus (Ducke, 1904) are presented here. Six new species are proposed (M. tayrona Silveira sp. nov.; M. anchicaya Silveira sp. nov.; M. caxiuana Silveira sp. nov.; M. verissimoi Silveira sp. nov.; M. rodriguesi Silveira sp. nov.; M. ryani Silveira sp. nov.), raising to nine the number of species in the M. punctatus group. The highest diversity of the group concentrates in northern South America, in Andean areas and Amazonia. New information concerning the very peculiar nests of these wasps is also given.

New species of pollen wasps Paramasaris fernandae sp. nov. (Hymenoptera, Vespidae, Masarinae) from a rain forest locality in Brazilian Amazonia.

Paramasaris fernandae Silveira, sp. nov. is described from the Brazilian state of Pará, and its affinities with other species in the genus are discussed. Record of this new species greatly expands geographical range of occurrences for Paramasaris Cameron as a whole, and in a kind of forest habitat unusual for the group.

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest. The knowledge of social wasp richness and biology in the Amazonian region is considered insufficient. Although the Amazonas state is the largest in the region, until now only two brief surveys were conducted there. Considering that the systematic inventory of an area is the first step towards its conservation and wise use, this study presents faunal data on social wasp diversity in a 25 km² area of "terra firme" (upland forest) at the Ducke Reserve, Manaus, Amazonas, Brazil. Wasps were collected in the understory, following a protocol of three collectors walking along 60 trails 1,000 m in extension for 16 days between August and October 2010. Methods used were active search of individuals with entomological nets and nest collecting. Fifty-eight species of social wasps, allocated in 13 genera, were recorded; 67% of the collected species belong to Polybia, Agelaia and Mischocyttarus; other genera were represented by only four species or less. The most frequent species in active searches were Agelaia fulvofasciata (DeGeer, 1773), Agelaia testacea (Fabricius, 1804) and Angiopolybia pallens (Lepeletier, 1836). Twelve species were collected in nests. Prior to this study, 65 Polistinae species were deposited at the INPA Collection. Collecting in the study grid, an area not previously sampled for wasps, resulted in an increase of 25% species, and species richness was 86. According to the results, there is evidence that the diversity of social wasps at the Ducke Reserve is even higher, making it one of the richest areas in the Brazilian Amazonia.

Social wasp species of Mischocyttarus (Phi) related to M. alfkenii (Ducke) and M. paraguayensis Zikán (Hymenoptera, Vespidae, Polistinae)

Social wasp species of Mischocyttarus (Phi) related to M. alfkenii (Ducke) and M. paraguayensis Zikán (Hymenoptera, Vespidae, Polistinae). A revision of the taxonomic status and an identification key are presented for species of the genus Mischocyttarus related to M. alfkenii (Ducke) and M. paraguayensis Zikán. Seven new species are proposed in the alfkenii and basimacula groups (M. achagua sp. nov.; M. arawak sp. nov.; M. awa sp. nov.; M. embera sp. nov.; M. muisca sp. nov.; M. uniformis sp. nov.; M. waunan sp. nov.), with five new synonymies [M. mamirauae Raw = M. alfkenii (Ducke); M. alfkenii excrucians Richards = M. flavicornis nigricornis Zikán = M. flavicornis Zikán; M. basimacula superpictus Richards = M. basimacula (Cameron)]. Specific status is also newly recognized for M. trinitatis Richards. Two new species are described in the paraguayensis and bahiae group (M. suzannae sp. nov.; M. tayacaja sp. nov.), while fifteen new synonymies are proposed (M. aracatubaensis Zikán = M. araujoi Zikán = M. costalimai Zikán = M. gilvus Zikán = M. infrastrigatoides Zikán = M. infrastrigatus Zikán = M. infrastrigatus Zikán = M. ornatulus Zikán = M. riograndensis Richards = M. rivulorum Richards = M. schrottkyi Zikán = M. scitulus Zikán = M. similaris Zikán = M. similatus Zikán = M. paraguayensis Zikán). These numbers change the picture of diversity in these species groups, as partly found in Richards's revision, published in 1978, reflecting higher diversity in northern Andean areas than in the Brazilian Atlantic region.

Vibrational corrections to the first hyperpolarizability of the lithium salt of pyridazine Li-H3C4N2.

In this work we report results of vibrational corrections to the polarizability and first hyperpolarizability of the lithium salt of pyridazine Li-H3C4N2 obtained at the second-order Mo̸ller-Plesset theory level with the aug-cc-pVDZ basis set. The calculations were carried out by means of the perturbation theoretical method of Bishop and Kirtman and also using a variational approach proposed here. The results obtained show that at the static limit, the pure vibrational corrections for the polarizability and first hyperpolarizability have the same order of magnitude of the corresponding electronic contributions. Comparisons between the results obtained through the two methods show that the perturbation theoretical method is not suitable to treat the system studied, while the variational methodology presented seems to be an alternative approach to treat anharmonic systems.