Abstract: In this study, the capacity and ultimate behavior of Reinforced Concrete (RC) and Steel Fiber Reinforced Concrete (SFRC) beams are evaluated. Nonlinear Finite Element Analysis (NLFEA) and the inverse analysis technique were used to model its structural response using the ATENA finite element software. The smeared crack approach, the crack band model, and advanced constitutive models were used to reproduce concrete fracture. The analyzed beams were subjected to rupture in a four-point bending test setup. The relationship between the shear span and the depth of the beams was 1.5. Four scenarios were analyzed, RC beams with and without stirrups, and SFRC beams without stirrups with volumes of 0.57% and 0.76%. The results obtained in the modeling are discussed in terms of the ability of the models to numerically reproduce the relationships: load versus displacement, load versus strain, crack patterns, and failure modes. The analysis techniques allowed to reproduce the experimental response of the beams with good agreement. They show great potential to solve structural engineering problems.

Lepidura Townes is a genus with an Andean distribution of the subfamily Mesochorinae, occurring in Chile and Argentina. Among the 14 species described, the males remain unknown in seven: L. callaina Dasch, L. improcera Dasch, L. mallecoensis Dasch, L. nigricephala Araujo & Vivallo, L. patagonica Araujo & Vivallo, L. seminitida Araujo & Vivallo and L. viridis Dasch. Based on the study of specimens deposited in the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia”, Argentina, the male of L. patagonica is described and illustrated for the flrst time. In addition, a new distribution record of L. olivacea Dasch in Argentina is also provided.

Lepidura Townes es un género con distribución andina de la subfamilia Mesochorinae, con especies presentes en Chile y Argentina. De las 14 especies descritas, los machos permanecen desconocidos en siete: L. callaina Dasch, L. improcera Dasch, L. mallecoensis Dasch, L. nigricephala Araujo & Vivallo, L. patagonica Araujo & Vivallo, L. seminitida Araujo & Vivallo y L. viridis Dasch. En base al estudio de especímenes depositados en el Museo Argentino de Ciencias Naturales "Bernardino Rivadavia”, Argentina, aquí se describe e ilustra por primera vez el macho de L. patagonica. Adicionalmente, se proporciona un nuevo registro de distribución de L. olivacea Dasch en Argentina.

The doryctine braconid wasp genus Caingangia Marsh is recorded for the first time from Argentina, based on specimens of C. wesa sp. nov. which is described and illustrated. A key to known species of the genus is provided.

El género Caingangia Marsh se cita por primera vez para la Argentina en base a especímenes de C. wesa sp. nov. que se describe e ilustra. Se brinda una clave para identificar las especies del género.

Dendrocerus ranquel sp. nov., from La Pampa, Argentina is described and ilustrated. Its affinities with other species of the group halidayi are discussed.

Se describe e ilustra Dendrocerus ranquel sp. nov. procedente de la provincia de La Pampa, Argentina. Se discuten sus afinidades con otras especies del grupo halidayi.