Two new species belonging to the braconid genus Bracon (Braconinae) are described from the tropical rainforest of Los Tuxtlas in the state of Veracruz, Mexico, B. laurae sp. nov. and B. rosamondae sp. nov. These species are morphologically similar and were reared from fruits of three Lauraceae species, Damburneya ambigens, D. salicifolia and Nectandra turbacensis. However, comparison of their DNA barcoding locus and a fragment of the nuclear ribosomal 28S gene confirmed their allospecificity. These two species share a number of morphological features with the two described Neotropical Bracon species that are known to be phytophagous (seed predators), B. phytophagus Quicke and B. zuleideae Perioto & Lara. We therefore propose a new species-group for the above four species, the B. phytophagus Quicke species-group, and suggest that the two newly described species also have a phytophagous feeding strategy.

A pesar de la importancia ecológica y económica de la Orinoquía colombiana, aún son escasos los  studios básicos sobre la vegetación, los cuales se requieren para planificar el manejo y la conservación de la flora de esta región. El objetivo de este estudio fue analizar la riqueza, composición y distribución geográfica de las plantas vasculares de la cuenca baja del río Pauto (Casanare-Colombia). Se hicieron muestreos de la vegetación durante las temporadas de sequía y lluvias en cuadrantes de 1x1 m en las sabanas y en parcelas de 50x20 m en los bosques, incluyendo áreas con transformación antropogénica.  e registraron 701 especies, 421 géneros y 121 familias en un catálogo sistemático; 52  de las especies no se habían registrado previamente en la flora de la Orinoquía. En las sabanas, las familias con mayor riqueza fueron Leguminosae sensu lato (43), Cyperaceae (42) y Poaceae (38); y en los bosques, Leguminosae sensu lato (49), Malvaceae y Rubiaceae (26 cada una). Las formas de crecimiento con más especies fueron las hierbas (294), seguidas de árboles (129) y sufrútices (111). La mayoría de las especies están ampliamente distribuidas en el Neotrópico y muchas se encuentran en las selvas húmedas, bosques secos y sabanas de Suramérica. En el futuro es necesario incrementar los muestreos en sabanas y en el estrato herbáceo de los bosques ribereños, así como los esfuerzos de categorización de las amenazas de la flora regional de la Orinoquía.

Premise: Although ecological differentiation driven by altitude and soil is hypothesized to promote coexistence of sympatric tree species of Damburneya (Lauraceae), the mechanistic role of leaf functional variation on ecological differentiation among co-occurring species remains unexplored. We aimed to determine whether the patterns of leaf trait variation reflect ecological differences among sympatric Damburneya species. We tested whether trait correlations underlying functional strategies and average species traits vary in response to local soil heterogeneity along an altitudinal gradient, potentially affecting species distributions. Methods: At two contrasting altitudes (100, 1100 m a.s.l.) in a Mexican tropical rainforest, we characterized soil chemical and physical properties and sampled four Damburneya species to quantify five leaf functional traits. We used linear models to analyze paired and multivariate trait correlations, spatial and interspecific effects on trait variation, and trait response to local soil heterogeneity. Relative contributions of intra-and interspecific variation to local trait variability were quantified with an ANOVA. Results: Soil nutrient availability was higher at low altitude, but all species had a high leaf N:P ratio across altitudes suggesting a limited P supply for plants. Species distribution differed altitudinally, with some species constrained to low or high altitude, potentially reflecting soil nutrient availability. Leaf traits responded to altitude and local soil properties, suggesting interspecific differences in functional strategies according to the leaf economics spectrum (conservative vs. acquisitive). Conclusions: The interspecific divergence in functional strategies in response to local environmental conditions suggests that trait variation could underlie ecological differentiation among Damburneya sympatric species.