Abstract A revision of the Nabis punctipennis complex is here provided. Nabis (Austronabis) subgen. nov. (type species: N. (A.) punctipennis Blanchard) from South America is described based on male and female genitalia. This new subgenus is compared with all the other Nabis subgenera in the world and a key for 13 Nabis subgenera is provided. Nabis (A.) subgen. nov. is composed of: N. (A.) argentinus Meyer-Dür, N. (A.) faminei Stål, N. (A.) paranensis Harris and N. (A.) punctipennis. Redescriptions of each species are given, with images of their male and female genitalia, including new characters of the male genitalia and new distributional records. We also discuss the taxonomic position of Nabis ashworthi Faúndez and Carvajal and propose that it should be transferred to the subgenus Nabis (Dolichonabis) Reuter, new combination.

Abstract: The genus Stenodema Laporte, 1832 is a group of grass-feeding plant bugs worldwide distributed, with five species recorded for the Subantarctic sub-region (sunsuMorrone 2015). Males of Stenodema longicuneata (Carvalho and Rosas, 1966) are redescribed and photographed. Stenodema laolaoensis (Carvalho, 1985) is proposed as a junior synonym of S. longicuneata. New geographic records are provided and distributional and biogeographic issues are discussed.

Apipé Grande Island is localized north of the province of Corrientes (Argentina), with the phytogeographic regions of the Chaco Húmedo and the Selva Paranaense adjacent to it. The objectives of the study were to determine the composition and arthropod assemblages in forest environments of Apipé Grande Island, and evaluate if they differ of continental arthropod communities of the same environment, and determine with which of those adjacent phytogeographic region (Chaco Húmedo or Selva Paranaense) shares more arthropod species. Five sites were sampled in each of the next studied areas: Apipé, Chaco Húmedo and Selva Paranaense, with a G-Vac over vegetation. Rank-abundance curves were generated to compare communities; and with a NMDS we analyzed the degree of assemblages association of species/morphospecies between sites. Raup-Crick standardized index was calculated to determine whether ecological communities have a nonrandom structure. Many arthropods species did not have high dispersal capabilities, but they were shared between the continental and Apipé communities, which suggests that the dispersal limitation of these species is not a constraint in the process of structuring assemblies. Environmental requirements of the species seem to be an important factor in determining the composition of these communities.

La isla Apipé Grande se encuentra al norte de la provincia de Corrientes, Argentina, siendo el Chaco Húmedo y la Selva Paranaense las regiones fitogeográficas adyacentes a ella. Aquí se determina la composición del ensamble de artrópodos de parches de bosques de Apipé Grande, se evalúa si presenta diferencias con comunidades de artrópodos de ambientes continentales similares, y se determina con cuál región fitogeográfica adyacente comparte más especies. Se muestrearon 5 sitios en cada una de las siguientes áreas: Apipé, Chaco Húmedo y Selva Paranaense, con un G-Vac sobre la vegetación. Se generaron curvas de rango-abundancia para comparar la composición de las comunidades, y con un NMDS se analizó el grado de similitud de los ensambles de especies/morfoespecies entre sitios. Se calculó el índice de Raup-Crick estandarizado, a fin de determinar si las comunidades se encuentran estructuradas al azar o no. Apipé presentó un ensamble propio, compartiendo un porcentaje de fauna con las comunidades continentales. Si bien muchos artrópodos compartidos entre el continente y Apipé no tienen altas capacidades de dispersión, esta limitación en la dispersión parece no ser un condicionamiento para estructurar los ensambles, siendo los requerimientos ambientales de las especies importantes para determinar la composición de las comunidades.

The syntypes of Lamprodema inerme Berg a Megalonotini, deposited in the collection of Museo de La Plata (Argentina) are examined and transferred to the monotypic genus Stictolethaeus O´Donnell in the tribe Lethaeini as Stictolethaeus inerme (Berg) (new combination) and Stictolethaeus slateri O´Donnell is treated as a junior synonym of Lamprodema inerme (new synonymy). The absence of inner laterotergites in the macropterous syntype reveals that further studies are needed in order to establish the correct position of Stictolethaeus inerme within a tribe.

El material tipo de Lamprodema inerme Berg, un Megalonotini, depositado en la colección del Museo de La Plata (Argentina) es examinado y la especie es transferida al género monotípico Stictolethaeus O´Donnell en la tribu Lethaeini como Stictolethaeus inerme (Berg) (nueva combinación) y Stictolethaeus slateri O´Donnell es relegada a sinónimo junior de Lamprodema inerme (nueva sinonimia). La ausencia de laterotergitos internos en el único ejemplar macróptero conocido revela que son necesarios más estudios para establecer la correcta ubicación de S. inerme.