Cohnella is a highly cellulolytic bacterial genus, which can be found in a variety of habitats. The aim of this study was to assess its presence in the digestive tract of termite species collected in North-eastern Argentina: Nasutitermes aquilinus, N. corniger and Cortaritermes fulviceps. Gut homogenates were incubated with cellulosic substrate for bacterial growth. Bacterial 16S rDNA was partially amplified using new primers for Cohnella spp. and cloned. Sequences obtained showed highest similarity (97.2-99.9%) with those of Cohnella spp. previously reported from diverse environments. Phylogenetic analysis tended to group the clones according to their host species and sampling sites. These results indicate the association of Cohnella-related intestinal symbionts with three common Neotropical termites. Their potential industrial application encourages further research.

Cohnella es un género de bacterias celulolíticas que puede ser encontrado en una variedad de hábitats. El propósito de este estudio fue registrar su presencia en el tracto digestivo de termitas (Nasutitermes aquilinus, N. corniger y Cortaritermes fulviceps) colectadas en el noreste argentino (NEA). Se incubaron homogenados de intestinos en sustrato celulósico para multiplicar las bacterias. Utilizando nuevos cebadores para Cohnella spp., se amplificó una porción del ADN ribosomal 16S bacteriano, el cual fue posteriormente clonado. Las secuencias obtenidas mostraron su mayor porcentaje de similitud (97,2-99,9%) con Cohnella spp., previamente reportadas en diversos ambientes. El análisis filogenético tendió a agrupar a los clones de acuerdo a la especie hospedante y al sitio de muestreo. Estos resultados indican que especies de termitas frecuentes en el NEA albergan simbiontes intestinales relacionados con el género Cohnella. Las potenciales aplicaciones industriales de estos microorganismos animan a profundizar los estudios.

Soil macrofauna from four natural and agricultural ecosystems with different disturbance degrees, located at the Esteros del Ibera ecoregion (Corrientes, Argentina) was analyzed in order to assess the impact of productive activities in this wetland. The diversity, abundance, density and biomass of the main invertebrate groups were determined and the analyzed communities were compared. The modified Conservation and Sustainable Management of Below Ground Biodiversity protocol was applied at four points on each site. The influence of different perturbation factors on the biota was analyzed. Soil macrofauna was composed by 19 invertebrate orders, mainly earthworms and arthropods (termites, ants and beetles were the most abundant). The differences between the analyzed assemblages were referred to taxonomic composition, diversity, order number and density, but they were not statistically significant for the last feature. Most individuals were detected in surface soil layer (0-10 cm) and biomass was higher on pastures although the orders of higher relative biomass were different at each site. On the bases of the similarities in the macrofaunal communities, the analyzed ecosystems formed two groups: cotton crop -forested pasture and natural forest- grazed pasture. Two of the analyzed perturbations (replacement of natural vegetation and soil removal) influenced the soil macrofauna. Ants and worms were identified as potential bioindicators in these assemblages, while subterranean termites were well represented, mainly in the more disturbed sites.

Se analizó la macrofauna del suelo de cuatro ambientes naturales y agroecosistemas localizados en zonas altas de la eco-región Esteros del Iberá (Corrientes, Argentina) con distintos grados de perturbación, a fin de contribuir a evaluar el impacto de las actividades productivas en este humedal. Se determinó la diversidad, abundancia, densidad y biomasa de los principales grupos y se compararon las comunidades analizadas. Se aplicó el protocolo de Conservación y Manejo Sustentable de la Biodiversidad del Suelo modificado, en cuatro puntos en cada sitio. Se analizó la influencia de distintos factores de perturbación sobre la biota. La macrofauna del suelo estuvo integrada por 19 órdenes de invertebrados, principalmente oligoquetos terrestres y artrópodos, entre los cuales las termitas, hormigas y coleópteros fueron los más abundantes. Las diferencias entre los ensambles analizados se evidenciaron en su composición taxonómica, diversidad, número de órdenes y densidad de los grupos más abundantes, pero ellas no fueron estadísticamente significativas para esta última característica. La mayoría de los individuos se detectaron en el estrato superficial del suelo (0-10 cm) y la biomasa fue más elevada en los pastizales aunque los órdenes de mayor biomasa relativa fueron distintos en cada sitio. Las similitudes entre ambientes agruparon por un lado al cultivo de algodón y al pastizal forestado, y por otro al bosque y al pastizal sometido a pastoreo. Dos de las perturbaciones ambientales analizadas (reemplazo de la vegetación natural y remoción del suelo) influyeron sobre las comunidades macroedáficas. Las hormigas y lombrices resultaron posibles invertebrados bioindicadores en estas comunidades, en tanto que las termitas subterráneas resultaron importantes por su diversidad y biomasa, principalmente en los dos ambientes con mayor grado de perturbación.

O conhecimento da biodiversidade de insetos em áreas naturais da Argentina é limitado e os cupins estão entre os menos estudados. Para conhecer a diversidade dos Isóptera em algumas áreas protegidas do país, foi feita uma amostragem de cupins em três parques nacionais da região noroeste da Argentina, durante 1995-1999. Os resultados aqui apresentados correspondem ao Chaco National Park (Província de Chaco), Iguassu National Park (Província de Misiones) e Mburucuya National Park (Província de Corrientes). Entre as quatro famílias de cupins registrados na Argentina, a família dos Termitidae foi a mais bem representada nas três áreas. Os gêneros registrados foram: Rugitermes Holmgren e Tauritermes Krishna (Kalotermitidae), Heterotermes Frogatt (Rhinotermitidae), Cornitermes Wasmann, Cortaritermes Mathews, Diversitermes Holmgren, Nasutitermes Dudley, Velocitermes Holmgren (Nasutitermitinae), Amitermes Silvestri, Microcerotermes Silvestri, Neocapritermes Holmgren, Termes Linné (Termitinae), Anoplotermes Muller, Aparatermes Fontes and Ruptitermes Mathews (Apicotermitinae) (Termitidae). Nenhuma das espécies de cupim coletadas foi comum para os três parques e apenas quatro foram coletadas em duas reservas. Devido ao arranjo particular dos cupins, que foi encontrado em cada parque, estas três áreas naturais protegidas podem ser consideradas como importantes reservas para a conservação da fauna de cupins na região noroeste da Argentina.

The knowledge of insect biodiversity in natural areas of Argentina is limited, and termites are among the understudied taxa. In order to assess the diversity of Isoptera in some protected areas of the country, termite sampling within three National Parks of the Northeast region of Argentina was developed during 1995-1999. The results presented in this paper correspond to the Chaco National Park (Province of Chaco), Iguassu National Park (Province of Misiones) and Mburucuya National Park (Province of Corrientes). Among the four termite families recorded from Argentina, the family Termitidae was the best represented at the three sampled areas. The recorded genera (15) were: Rugitermes Holmgren and Tauritermes Krishna (Kalotermitidae), Heterotermes Frogatt (Rhinotermitidae), Cornitermes Wasmann, Cortaritermes Mathews, Diversitermes Holmgren, Nasutitermes Dudley, Velocitermes Holmgren (Nasutitermitinae), Amitermes Silvestri, Microcerotermes Silvestri, Neocapritermes Holmgren, Termes Linné (Termitinae), Anoplotermes Müller, Aparatermes Fontes and Ruptitermes Mathews (Apicotermitinae) (Termitidae). None of the collected termite species was common to the three National Parks, and only four of them were detected at two of the reserves. Due to the particular assemblage of termites found at each park, these three natural protected areas could be considered important reserves for the conservation of the termite fauna from the Northeast region of Argentina.