Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) and other nematode genera associated with insects from Pinus pinaster in Portugal

Insects associated with maritime pine, Pinus pinaster, in Portugal were collected and screened for the presence of Bursaphelenchus species. Nematodes were identified using Internal Transcribed Spacers-Restriction Fragment Length Polymorphism (ITS-RFLP) analysis of dauer juveniles and morphological identification of adults that developed from dauer juveniles on fungal cultures or on cultures in pine wood segments at 26 C. Several associations are described: Bursaphelenchus teratospicularis and Bursaphelenchus sexdentati are associated with Orthotomicus erosus; Bursaphelenchus tusciae, B. sexdentati and/or Bursaphelenchus pinophilus with Hylurgus ligniperda and Bursaphelenchus hellenicus with Tomicus piniperda, Ips sexdentatus and H. ligniperda. An unidentified Bursaphelenchus species is vectored by Hylobius sp. The previously reported association of Bursaphelenchus xylophilus with Monochamus galloprovincialis was confirmed. The association of Bursaphelenchus leoni with Pityogenes sp. is not definitively established and needs further studies for clarification. Other nematode genera besides Bursaphelenchus were found to be associated with the insects sampled, including two different species of Ektaphelenchus, Parasitorhabditis sp., Parasitaphelenchus sp., Contortylenchus sp. and other unidentified nematodes. The Ektaphelenchus species found in O. erosus is morphologically similar to B. teratospicularis found in the same insect; adults of both the species are found in cocoon-like structures under the elytra of the insects. Introduction Approximately one third of the nematodes belonging to the order Aphelenchida Siddiqi, 1980 are associated with insects (Poinar, 1983). These nematodes establish a variety of associations with the insects, which may be described as commensalism, e.g. phoresy (to the benefit of the nematode but not affecting the insect), mutualism (both the organisms benefit) or parasitism (nematodes benefit at the expense of the insect) (Giblin-Davis, 2004). Most Bursaphelenchus Fuchs, 1937 species are mycetophagous, feeding on fungi in the galleries of bark beetles and thu

Cholini (Coleoptera: Curculionidae, Molytinae) depositados na Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia

In Brazilian Amazonia, Cholini (Coleoptera, Curculionidae, Molytinae) is represented by 53 species distributed in seven generaAmeris Dejean, 1821; Cholus Germar, 1824; Homalinotus Sahlberg, 1823; Lobaspis Chevrolat, 1881; Odontoderes Sahlberg, 1823; Ozopherus Pascoe, 1872 and Rhinastus Schoenherr, 1825. This work documents the species of Cholini housed in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil and gives the geographical and biological data associated with them. A total of 186 Cholini specimens were identified as belonging to 14 species (13 from Brazilian Amazonia) and five genera (Cholus, Homalinotus, Odontoderes, Ozopherus and Rhinastus). Only 24% of the Cholini species reported from Brazilian Amazonia are actually represented in the INPA collection, underscoring the need for a more systematical collecting based on available biological information. The known geographical distribution was expanded for the following speciesCholus granifer (Chevrolat, 1881) for Brazil; C. pantherinus (Olivier, 1790) for Manaus (Amazonas); Cholus parallelogrammus (Germar, 1824) for Piraquara (Paraná); Homalinotus depressus (Linnaeus, 1758) for lago Janauacá (Amazonas) and rio Tocantins (Pará); H. humeralis (Gyllenhal, 1836) for Novo Airão, Coari (Amazonas) and Porto Velho (Rondônia); H. nodipennis (Chevrolat, 1878) for Carauari, Lábrea (Amazonas) and Ariquemes (Rondônia); H. validus (Olivier, 1790) for rio Araguaia (Brasil), Manaus (Amazonas), rio Tocantins (Pará), Porto Velho and BR 364, Km 130 (Rondônia); Odontoderes carinatus (Guérin-Méneville, 1844) for Manaus (Amazonas); O. spinicollis (Boheman, 1836) for rio Uraricoera (Roraima); and Ozopherus muricatus Pascoe, 1872 for lago Janauacá (Amazonas). Homalinotus humeralis is reported for the first time from "urucuri" palm, Attalea phalerata Mart. ex Spreng.Na Amazônia brasileira, Cholini (Coleoptera, Curculionidae, Molytinae) é representada por 53 espécies, distribuídas em sete gêneros: Ameris Dejean, 1821; Cholus Germar, 1824; Homalinotus Sahlberg, 1823; Lobaspis Chevrolat, 1881; Odontoderes Sahlberg, 1823; Ozopherus Pascoe, 1872 e Rhinastus Schoenherr, 1825. Este trabalho documenta as espécies de Cholini depositadas na Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia, Manaus, Brasil, além de apresentar a distribuição geográfica e informações sobre a biologia dessas espécies. Foram identificados 186 espécimes de Cholini, pertencentes a 14 espécies (13 da Amazônia brasileira) e cinco gêneros (Cholus, Homalinotus, Odontoderes, Ozopherus e Rhinastus). Somente 24% das espécies de Cholini registradas para a Amazônia brasileira estão representadas na coleção do INPA, ressaltando a necessidade de um esforço de coleta sistemático baseado na informação biológica disponível. Foi ampliada a distribuição geográfica conhecida das seguintes espécies: Cholus granifer (Chevrolat, 1881) para Brasil; C. pantherinus (Olivier, 1790) para Manaus (Amazonas); Cholus parallelogrammus (Germar, 1824) para Piraquara (Paraná); Homalinotus depressus (Linnaeus, 1758) para lago Janauacá (Amazonas) e rio Tocantins (Pará); H. humeralis (Gyllenhal, 1836) para Novo Airão, Coari (Amazonas) e Porto Velho (Rondônia); H. nodipennis (Chevrolat, 1878) para Carauari, Lábrea (Amazonas) e Ariquemes (Rondônia); H. validus (Olivier, 1790) para rio Araguaia (Brasil), Manaus (Amazonas), rio Tocantins (Pará), Porto Velho e BR 364, Km 130 (Rondônia); Odontoderes carinatus (Guérin-Méneville, 1844) para Manaus (Amazonas); O. spinicollis (Boheman, 1836) para rio Uraricoera (Roraima) e Ozopherus muricatus Pascoe, 1872 para lago Janauacá (Amazonas). Homalinotus humeralis é associado pela primeira vez com a palmeira urucuri Attalea phalerata Mart. ex Spreng

Mechanisms underlying a thalamocortical transformation during active tactile sensation

During active somatosensation, neural signals expected from movement of the sensors are suppressed in the cortex, whereas information related to touch is enhanced. This tactile suppression underlies low-noise encoding of relevant tactile features and the brain’s ability to make fine tactile discriminations. Layer (L) 4 excitatory neurons in the barrel cortex, the major target of the somatosensory thalamus (VPM), respond to touch, but have low spike rates and low sensitivity to the movement of whiskers. Most neurons in VPM respond to touch and also show an increase in spike rate with whisker movement. Therefore, signals related to self-movement are suppressed in L4. Fast-spiking (FS) interneurons in L4 show similar dynamics to VPM neurons. Stimulation of halorhodopsin in FS interneurons causes a reduction in FS neuron activity and an increase in L4 excitatory neuron activity. This decrease of activity of L4 FS neurons contradicts the "paradoxical effect" predicted in networks stabilized by inhibition and in strongly-coupled networks. To explain these observations, we constructed a model of the L4 circuit, with connectivity constrained by in vitro measurements. The model explores the various synaptic conductance strengths for which L4 FS neurons actively suppress baseline and movement-related activity in layer 4 excitatory neurons. Feedforward inhibition, in concert with recurrent intracortical circuitry, produces tactile suppression. Synaptic delays in feedforward inhibition allow transmission of temporally brief volleys of activity associated with touch. Our model provides a mechanistic explanation of a behavior-related computation implemented by the thalamocortical circuit