An updated checklist of the Odonata from Argentina

An updated checklist of the Odonata spp. known to occur in Argentina is presented along with distributional information by province. 27 spp. are removed from previous listings, and 32 new records are added, bringing the total number of spp. to 271. Of the new records, 14 correspond to new spp. currently under description. The distribution of the 17 species presently known to be endemic to Argentina is mapped.Instituto de Limnología "Dr. Raúl A. Ringuelet

Oreiallagma gen. nov. with a redefinition of Cyanallagma Kennedy 1920 and Mesamphiagrion Kennedy 1920, and the description of M. dunklei sp. nov. and M. ecuatoriale sp. nov. from Ecuador (Odonata: Coenagrionidae)

In this paper we re-evaluate Cyanallagma Kennedy 1920, which currently includes 15 species, and we address another five species that share diagnostic characters with some of them but are currently placed within Leptagrion Selys 1876, Mesamphiagrion Kennedy 1920, and Telagrion Selys 1876. A new genus, Oreiallagma, is described to include five species originally placed in Acanthagrion Selys 1876, Cyanallagma, and Telagrion. These species are O. thelkterion (De Marmels 1997) (type species), O. acutum (Ris 1918), O. oreas (Ris 1918), O. prothoracicum (Kimmins 1945), and O. quadricolor (Ris 1918). The last stadium larva of O. quadricolor is described. The remaining species currently includedin Cyanallagma are allocated to two separate genera: Cyanallagma sensu stricto and Mesamphiagrion. Cyanallagma sensu stricto comprises southern South American species including the type species, Cyanallagma interruptum (Selys 1876). Mesamphiagrion Kennedy 1920 includes a cluster of species from northwestern South America that are considered congeneric with the type species Mesamphiagrion occultum (Ris 1918). Two new species from Ecuador, M. dunklei and M. ecuatoriale, are described and Argia hebdomatica Navás 1934 is found to be a junior synonym of M. ovigerum (Calvert 1909). Synonymic lists, diagnoses, illustrations, keys, and distribution maps for the three genera are provided.Fil: Von Ellenrieder, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Garrison, Rosser W.. California Department of Food and Agriculture; Estados Unido

Redefinition of Leptobasis Selys with the synonymy of Chrysobasis Rácenis and description of L. mauffrayi sp. nov. from Peru (Odonata: Coenagrionidae)

Chrysobasis is synonymized with Leptobasis. The latter is diagnosed by the combination of rounded frons, CuP reaching hind margin of wing, CuA relatively short, and supplementary pretarsal claw reduced to vestigial, and by the presence on the distal segment of the genital ligula of a pair of chitinized, flap-like, movable processes directed posteriorly. A new species from Peru, L. mauffrayi, is described, and illustrations, maps, and keys for all Leptobasis species are provided.Chrysobasis es sinonimizado con Leptobasis, el último es diagnosticado por la combinación de frente redondeada, CuP alcanzando el margen posterior del ala, CuA relativamente corta, y uña pretarsal suplementaria reducida a vestigial, y por la presencia de un par de procesos quitinizados, a modo de lengüetas, movibles, dirigidos posteriormente en el segmento distal de la ligula genital. Se describe una nueva especie de Perú, L. mauffrayi, y se proveen ilustraciones, mapas y claves para todas las especies de Leptobasis.Fil: Garrison, Rosser W.. California Department of Food and Agriculture; Estados UnidosFil: Von Ellenrieder, Natalia. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Redefinition of Mesoleptobasis Sjöstedt 1918 with the inclusion of Metaleptobasis cyanolineata (Wasscher 1998) comb. nov. and description of a new species, Mesoleptobasis elongata (Odonata: Coenagrionidae)

Metaleptobasis cyanolineata es transferida a Mesoleptobasis y una nueva especie, Mesoleptobasis elongata, es descripta. El género es diagnosticado por la combinación de frente redondeada, pronoto marcadamente modificado con largos procesos al menos en machos, patrón de coloración pterotorácico sin raya medio-dorsal oscura, pretarso con diente suplementario vestigial o ausente, vena descendente del cuadrángulo formando una línea recta hasta el margen del ala, y lígula genital con un pequeño pliegue interno y con proyecciones a modo de espinas en los margenes laterales distalmente a la flexura. Se proveen ilustraciones, mapa y clave para sus especies.Metaleptobasis cyanolineata is transferred to Mesoleptobasis and a new species, Mesoleptobasis elongata, is described. The genus is diagnosed by the combination of rounded frons, highly modified pronotum with long processes at least in males, pterothoracic color pattern lacking dark mid-dorsal stripe, pretarsus with supplementary tooth vestigial or absent, vein descending from quadrangle forming an unbroken line to wing margin, and genital ligula with a small inner fold and with spine-like projections on lateral margins distal to flexure. Its species are illustrated, mapped, and keyed.Fil: Garrison, Rosser W.. California Department of Food and Agriculture; Estados UnidosFil: Von Ellenrieder, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin

Drepanoneura gen. nov. for Epipleoneura letitia and Protoneura peruviensis, with description of eight new Protoneuridae from South America (Odonata: Protoneuridae)

A new genus, Drepanoneura (type species Drepanoneura loutoni sp. nov.), is described to include Epipleoneura letitia Donnelly, Protoneura peruviensis Fraser, and six new congeneric species from South America: D. donnellyi, D. flinti, D. janirae, D. loutoni, D. muzoni, and D. tennesseni. Drepanoneura is similar to Epipleoneura and Epipotoneura in venational characters, but differs from them in morphology of male cercus, genital ligula, female pronotum, and epiproct. A new species of Epipleoneura from Venezuela, E. demarmelsi, and a new species of Epipotoneura from Brazil, E. machadoi, are described, and diagnostic illustrations for the poorly known Epipotoneura nehalennia Williamson are also presented. A generic characterization, diagnoses, and keys for species of Drepanoneura are provided, as well as diagnostic illustrations and distribution maps for all involved species.Fil: Von Ellenrieder, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Garrison, Rosser W.. California Department of Food and Agriculture; Estados Unido

What is Amphipteryx agrioides Selys 1853 (Odonata: Amphipterygidae)?

The family Amphipterygidae comprises a group of moderately large, robust species of pan-tropical damselflies. It was first recognized by Selys (1853) as his "6me legion" based on the description of a unique female which he named "Amphipteryx agrioïdes." Its provenance ("Colombie. [Collect. Selys.]") has remained a mystery as no specimens of this genus had subsequently been collected from South America. Selys (1854a: 241, 243) expanded on the distribution of the specimen noting (page 241) that it had been collected “dans la province de Cumana (Amérique méridionale équatoriale)” and (page 243) “d’après un exemplaire recueilli par M. Funck, et qui se trouvait avec l’ Hetaerina majuscula et l’ Agrion (Hyponevra) Funcki….” De Marmels (1990) dismissed the record of A. agrioides from “Cumaná [Venezuela]” as unlikely and suggested deletion of the species from that country. The single holotype female was apparently never re-examined, except by the late B.E. Montgomery who never published his observations, until recently (von Ellenrieder & Garrison 2007). Calvert (1901) in his Biologia CentraliAmericana assigned this name to specimens from Mexico and Guatemala. He described the male for the first time and gave a description of the female comparing it with the original description and noting that "The hind prothoracic lobe also possesses two dorsal lamellate processes (not mentioned by Selys)…." González (1991) described A. longicaudatus (should be A. longicaudata; Novelo 1995) from Oaxaca, Mexico and distinguished this species from A. agrioides based only on Calvert's (1901) description and illustrations. Several years ago, Rosser W. Garrison was sent digital images of the holotype female of A. agrioides by Jérôme Constant of the IRSNB, and observed that the pronotal armature differed from specimens given this name by Calvert (1901) and González (1991) (Garrison pers. comm.). Since Amphipteryx is the type genus of the family Amphipterygidae, it is imperative that its type species, A. agrioides, be correctly assigned to specimens. The purpose of this paper is to determine the correct identity of A. agrioides, provide diagnostic illustrations of the same, and discuss the location of its type locality.Fil: González Soriano, Enrique. Universidad Nacional Autónoma de México. Departamento de Botánica. Instituto de Biología; MéxicoFil: Von Ellenrieder, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin

Description of the female and larva of Phyllogomphoides joaquini Rodrigues Capitulo, 1992 (Anisoptera: Gomphidae)

The ♀ and last larval instar are described and illustrated based on specimens from Argentina (Buenos Aires province). The ♀ is unique in the possession of a subapical tooth on each lobe of the vulvar scale, and it can be besides distinguished from P. andromeda, the only other Phyllogomphoides sp. found in Argentina, by the pterothoracic colour pattern. The larva differs from all known South American Phyllogomphoides larvae by the crenate inner margin of the labial palp.Instituto de Limnología "Dr. Raúl A. Ringuelet

Estimation of electrical conductivity of a layered spherical head model using electrical impedance tomography

Electrical Impedance Tomography (EIT) is a non-invasive method that aims to create an electrical conductivity map of a volume. In particular, it can be applied to study the human head. The method consists on the injection of an unperceptive and known current through two electrodes attached to the scalp, and the measurement of the resulting electric potential distribution at an array of sensors also placed on the scalp. In this work, we propose a parametric estimation of the brain, scalp and skull conductivities using EIT over an spherical model of the head. The forward problem involves the computation of the electric potential on the surface, for given the conductivities and the injection electrode positions, while the inverse problem consists on estimating the conductivities given the sensor measurements. In this study, the analytical solution to the forward problem based on a three layer spherical model is first described. Then, some measurements are simulated adding white noise to the solutions and the inverse problem is solved in order to estimate the brain, skull and scalp conductivity relations. This is done with a least squares approach and the Nelder-Mead multidimensional unconstrained nonlinear minimization method.Facultad de Ingenierí

Optimal design of on-scalp electromagnetic sensor arrays for brain source localisation

Optically pumped magnetometers (OPMs) are quickly widening the scopes of noninvasive neurophysiological imaging. The possibility of placing these magnetic field sensors on the scalp allows not only to acquire signals from people in movement, but also to reduce the distance between the sensors and the brain, with a consequent gain in the signal-to-noise ratio. These advantages make the technique particularly attractive to characterise sources of brain activity in demanding populations, such as children and patients with epilepsy. However, the technology is currently in an early stage, presenting new design challenges around the optimal sensor arrangement and their complementarity with other techniques as electroencephalography (EEG). In this article, we present an optimal array design strategy focussed on minimising the brain source localisation error. The methodology is based on the Cramér-Rao bound, which provides lower error bounds on the estimation of source parameters regardless of the algorithm used. We utilise this framework to compare whole head OPM arrays with commercially available electro/magnetoencephalography (E/MEG) systems for localising brain signal generators. In addition, we study the complementarity between EEG and OPM-based MEG, and design optimal whole head systems based on OPMs only and a combination of OPMs and EEG electrodes for characterising deep and superficial sources alike. Finally, we show the usefulness of the approach to find the nearly optimal sensor positions minimising the estimation error bound in a given cortical region when a limited number of OPMs are available. This is of special interest for maximising the performance of small scale systems to ad hoc neurophysiological experiments, a common situation arising in most OPM labs