Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05), suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05). The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007-08 the sex ratio was biased toward males (1 F:2.26 M), while in 2008-09 it was biased toward females (1.35 F:1 M). The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05). We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species.

The rapid advances in cyber-infrastructure, bioinformatics, digital imaging and related information technologies facilitate the access to taxonomic data and allow generating new information on a scale appropriate to meet the decline in biodiversity. Basic taxonomic information, such as taxonomic literature, catalogues, specimen-level data, location of types, and interactive keys are already available, at least for some groups, on the Web. In this article we explore the modern means of disseminating taxonomic information, mostly entomological information, in the Internet; we review some of the different ways taxonomists have so far made use of the Web or will be able to do so in the near future, and how modern means of sharing data, especially via the Internet, are being used to streamline taxonomic work and improve links with end users.

Los rápidos avances en la ciber-infraestructura, la bioinformática, la fotografía digital y las tecnologías de la información contribuyen a acceder fácilmente al conocimiento taxonómico y permiten generar información a una escala acorde con las necesidades de la crisis de la biodiversidad. El conocimiento taxonómico básico, como literatura taxonómica, catálogos de nombres científicos, registros de ejemplares, localización de ejemplares tipo en colecciones biológicas, y claves interactivas de varios grupos de organismos ya están disponibles a través de Internet. En este artículo, se analiza cómo la información taxonómica, principalmente la entomológica, es presentada a la comunidad en Internet; se discuten las diferentes formas en que la taxonomía ya ha hecho uso de este medio o podrá hacerlo en un futuro cercano, y cómo los actuales medios de compartir datos, especialmente a través de Internet, están siendo utilizados para hacer más eficientes las tareas taxonómicas, realzar las publicaciones y mejorar los vínculos con los usuarios.

This contribution records for the first time the subfamily Proctolabinae from Argentina. This subfamily contains 29 genera and 209 species restricted to the Neotropics with only one genus, Eucephalacris Descamps, reaching south as far as Mato Grosso in Brazil and northern Paraguay. Specimens belonging to Eucephalacris borellii (Giglio-Tos) were collected in Misiones province. The presence of this species registered herein raises to eleven the number of Acrididae subfamilies known to occur in the country, and highlights the importance of conducting surveys of Acridoidea and Orthoptera in general, in diverse regions of Argentina. Brief diagnoses and illustrations of the characters that allowed the identification of the genus and species are also given in this contribution.

Esta contribución registra por primera vez la subfamilia Proctolabinae para la Argentina. La subfamilia Proctolabinae contiene 29 géneros y 209 especies restringidas a la región Neotropical, con sólo uno de sus géneros, Eucephalacris Descamps, que llega al sur hasta Mato Grosso en Brasil y el norte de Paraguay. Ejemplares pertenecientes a Eucephalacris borellii (Giglio-Tos) fueron colectados en el departamento de Guaraní, provincia de Misiones. La presencia de Eucephalacris borellii, registrada en este trabajo, eleva a once el número de subfamilias de Acrididae presentes en la Argentina, y destaca la necesidad de realizar relevamientos sobre la diversidad de Acridoidea y de Orthoptera en general, en diversas regiones de nuestro país. También se brindan en esta contribución una breve diagnosis e ilustraciones de los caracteres que permiten la identificación del género y de la especie.