Systematic assessment of nymphs of Diesingiinae (Pentastomida: Sebekidae) parasitizing Palloceros harpagos (Cyprinodontiformes: Poeciliidae) from Parque Nacional Iguazú, Argentina: filling gaps in an incomplete phylogenetic framework.

During a search for parasites in fishes from Iguazu River, Argentina, a nymph of pentastomid was found encysted on mesenteries of Phalloceros harpagos. The 28S rDNA and COI mt-DNA were used to compare with the sequences deposited in the GenBank. Pentastomid nymphs belong to the subfamily Diesingiinae (Sebekidae) for having chloride cell pores distributed in a single row per annulus; also, the hooks and rows of spines of our material differ to other genera. Present specimens are most likely Diesingia sp., having 63-74 annuli, a U shaped oral cadre with fibers closing anteriorly and a peg like extension of the oral cadre. The 28S rDNA analysis places our samples into a sister group of Alofia sp., but the COI mt-DNA situate them on the base of the clade. In conclusion, our pentastomid positively belongs to Diesingia sp., however, indisputable assignation requires a reliable description of the nymph, or the availability of sequences linking nymphs and adults, which even could provide evidence of a new hitherto undescribed genus. Aditionally, the systematic position of Sebekia oxycephala previously described by P. harpagos is discussed on the basis of our results, allowing us to suggest a re-assignation of such specimens to the genus Diesingia.

Molecular phylogenetic relationship between Philometroides tahieli (Nematoda, Philometridae) and other philometrids from South America.

In South America, the family Philometridae is represented by several genera and species. In particular, Philometra and Philometroides are the most speciose genera. In Argentina, only Philometroides tahieli has been reported so far. The main objective of this study was to analyze the phylogenetic relationship between Ps. tahieli and other South American philometrids using molecular data. The molecular analysis was performed using a female specimen of Ps. tahieli found on the opercular muscle of a juvenile Micropogonias furnieri from brackish waters in Argentina. Phylogenetic relationships were studied based on partial sequences of the 18S rDNA and 28S rDNA genes. In the 18S rDNA tree, Ps. tahieli was mainly grouped with other Philometroides from freshwater hosts from China, sharing the site of infection (head tissues or muscles). In the 28S rDNA tree, obtained with fewer sequences, Ps. tahieli is related species from subcutaneous tissues of head. This study contributes with information on philometrids and confirms the presence of different lineages among South American species, with Ps. tahieli representing a new one. Further studies on South American species using more molecular markers and new morphological characters will improve our knowledge of philometrid biodiversity and phylogeny.

Molecular data reveal hidden diversity of the genus Clinostomum (Digenea, Clinostomidae) in Argentina, with the description of a new species from Ardea cocoi (Ardeidae).

The genus Clinostomum has been recently a subject of a large number of molecular phylogenetic studies that have uncovered a larger species diversity than we thought. In Argentina, only two nominal species have been reported, namely C. detruncatum and C. marginatum. Three putative species represented by metacercariae were recently molecularly diagnosed, and there are at least two additional metacercarial morphotypes diagnosed on morphological grounds. Here, we molecularly characterized specimens of Clinostomum sampled from freshwater fishes and fish-eating birds from Argentina through mtDNA cytochrome c oxidase subunit I (COI). Unexpectedly, the phylogenetic analysis uncovered three new additional genetic lineages, two of them corresponding to metacercarial stages and another matching COI sequences of C. heluans Braun, 1899, being considered conspecific, whereas the others still require formal description. Additionally, we add a new host species for a lineage molecularly diagnosed in a previous study. The adult specimens recovered from A. cocoi in Buenos Aires Province represented a new species clearly distinguished from the two species previously reported in Argentina. Clinostomum detruncatum is distinguished from the new species by possessing a characteristic tenoidean uterus, and testes located more posteriorly. Clinostomum marginatum is morphologically similar but differs from the new species in having rounded ovary, posterior testis lobated, and lateral cirrus-sac and displacing the anterior testis, and vitelline follicles not extending beyond the caeca end. Our study raises the number of Clinostomum species in Argentina up to 10. We describe the new species herein.

Detection of Flaviviral-Like DNA Sequences in Aedes aegypti (Diptera: Culicidae) Collected From Argentina.

Diseases caused by flaviviruses are a major public health burden across the world. In the past decades, South America has suffered dengue epidemics, the re-emergence of yellow fever and St. Louis encephalitis viruses, and the introduction of West Nile and Zika viruses. Many insect-specific flaviviruses (ISFs) that cannot replicate in vertebrate cells have recently been described. In this study, we analyzed field-collected mosquito samples from six different ecoregions of Argentina to detect flaviviruses. We did not find any RNA belonging to pathogenic flaviviruses or ISFs in adults or immature stages. However, flaviviral-like DNA similar to flavivirus NS5 region was detected in 83-100% of Aedes aegypti (L.). Despite being previously described as an ancient element in the Ae. aegypti genome, the flaviviral-like DNA sequence was not detected in all Ae. aegypti samples and sequences obtained did not form a monophyletic group, possibly reflecting the genetic diversity of mosquito populations in Argentina.

Interacción entre Epipompilus platensis (Hymenoptera: Pompilidae) y Ariadna mollis (Araneae: Segestridae) / Interaction between Epipompilus platensis (Hymenoptera: Pompilidae) and Ariadna mollis (Araneae: Segestridae)

Resumen En el presente estudio se dan a conocer por primera vez, datos sobre la interacción entre ejemplares de avispas de la especie Epipompilus platensis Roig Alsina, 2017 (Hymenoptera, Pompilidae) y arañas de la especie Ariadna mollis (Holmberg 1876) (Araneae, Segestriidae), en las localidades de Punta Lara (partido de Ensenada) y José Hernández (partido de La Plata), ambas pertenecientes a la provincia de Buenos Aires. Se recolectaron varios ejemplares de A. mollis en el mes de abril del 2015, y se seleccionaron aquellos que presentaban un huevo o una pequeña larva adherida al dorso del abdomen. Se mantuvieron bajo observación en bioterio hasta completar el desarrollo al estado adulto de la avispa. Del total de las arañas colectadas, el 9.6% se encontró parasitado por avispas. De ese porcentaje, cuatro larvas de E. platensis llegaron al estado adulto (tres hembras y un macho). Los resultados obtenidos contribuyen al conocimiento de una nueva interacción entre avispas y arañas.

Abstract In the present study, data on the interaction between wasp specimens of the species Epipompilus platensis Roig Alsina, 2017 (Hymenoptera, Pompilidae) and spiders of the species Ariadna mollis (Holmberg 1876) (Araneae, Segestriidae) are presented for the first time. Present in the localities of Punta Lara (Partido de Ensenada) and José Hernández (Partido de La Plata), both belonging to the province of Buenos Aires. Several specimens of A. mollis were collected on april 2015, and those that presented an egg or a small larva attached to the back of the abdomen were selected. They were kept under observation in a bioterium until completing the development of the wasp's adult state. Of the total spiders collected, 9.6% were parasitized by wasps. Of that percentage, four larvae of E. platensis reached the adult stage (three females and one male). The results obtained contribute to the knowledge of a new interaction between wasps and spiders.

Natural occurrence in Argentina of a new fungal pathogen of cockroaches, Metarhizium argentinense sp. nov.

The aim of this study was to search for entomopathogenic fungi that infect wild cockroaches in forest ecosystems in two protected natural areas of Argentina. Two isolates of Metarhizium argentinense were obtained and identified from wild cockroaches (Blaberidae: Epilamprinae) through the use of morphological characteristics and molecular phylogenetic analyses. This novel species was found in Argentina and is a member of the Metarhizium flavoviride species complex. Phylogenetic analyses, based on sequence similarity analysis using internal transcribed spacer (ITS) and a set of four protein-coding marker sequences (EF1A, RPB1, RPB2 and BTUB), supported the status of this fungus as a new species. In addition, we tested the biological activity of the new species through assays against Blattella germanica nymphs and found that the two evaluated isolates were pathogenic. However, isolate CEP424 was more virulent and caused a confirmed mortality of 76 % with a median lethal time of 7.2 d. This study reports the southernmost worldwide location of a Metarhizium species that infects cockroaches and will help expand the knowledge of the biodiversity of pathogenic fungi of Argentine cockroaches.

Geometric morphometric on a new species of Trichodinidae. A tool to discriminate trichodinid species combined with traditional morphology and molecular analysis.

This study reports a new Trichodinidae, Trichodina bellottii n. sp., parasitizing the pearly fish Austrolebias bellottii from Buenos Aires, Argentina. Its small subunit ribosomal ribonucleic acid (SSU rDNA) was sequenced for the first time. Based on the results from morphological identification, SSU rDNA sequencing, and Elliptical Fourier analysis, the new species was identified and compared with similar species. Phylogenetic analysis revealed that the genetic distances among the new species and similar species reached interspecific levels, furthermore, the phylogenetic study also validated the identification of T. bellottii n. sp. and its placement in the genus Trichodina. To be able to quantitatively describe the differences in shapes with similar species, this study used the elliptic Fourier analysis by first time in this genus.

Contribution to the knowledge of pathogenic fungi of spiders in Argentina: Southernmost record in the world / Aporte al conocimiento de los hongos patógenos de arañas en Argentina: El registro más austral del mundo

The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina.

El objetivo de este estudio fue identificar hongos entomopatógenos de arañas en un área protegida de la provincia de Buenos Aires, Argentina. La especie de araña identificada fue Stenoterommata platensis. Los patógenos identificados fueron Lecanicillium aphanocladii Zare y W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones y Samson y Ophiocordyceps caloceroides (Berk y M.A. Curtis). Este estudio constituye el registro más austral del mundo y contribuye a ampliar el conocimiento de la biodiversidad de hongos patógenos de arañas en Argentina.

Contribution to the knowledge of pathogenic fungi of spiders in Argentina. Southernmost record in the world.

The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina.

Description and host interactions of a new species of Exetasis Walker (Diptera: Acroceridae), with a key to species of the genus.

Exetasis jujuyensis Gillung sp. nov. (Acroceridae) is described from Argentina and a dichotomous key to species of Exetasis Walker is provided. Detailed observations are presented on the effect of fly larval development on the behavior of the host spider (Acanthoscurria sternalis Pocock (Theraphosidae)).