Water-repellent plant surface structure induced by gall-forming insects for waste management.

Many animals and plants have evolved elaborate water-repellent microstructures on their surface, which often play important roles in their ecological adaptation. Here, we report a unique type of water-repellent structure on a plant surface, which develops as an insect-induced plant morphology in a social context. Some social aphids form galls on their host plant, in which they produce large amounts of hydrophobic wax. Excreted honeydew is coated by the powdery wax to form 'honeydew balls', which are actively disposed by soldier nymphs through an opening on their gall. These activities are enabled by a highly water-repellent inner gall surface, and we discovered that this surface is covered with dense trichomes that are not found on normal plant surfaces. The trichomes are coated by fine particles of the insect-produced wax, thereby realizing a high water repellency with a cooperative interaction between aphids and plants. The plant leaves on which the gall is formed often exhibit patchy areas with dense trichomes, representing an ectopic expression of the insect-induced plant morphology. In the pouch-shaped closed galls of a related social aphid species, by contrast, the inner surface was not covered with trichomes. Our findings provide a convincing example of how the extended phenotype of an animal, expressed in a plant, plays a pivotal role in maintaining sociality.

Communities of anamorphic fungi on green leaves and leaf litter of native forests of Scutia buxifolia and Celtis tala: Composition, diversity, seasonality and substrate specificity / Comunidades de hongos anamórficos en hojas verdes y hojarasca de bosques nativos deScutia buxifolia y Celtis tala: composición, diversidad, estacionalidad y especificidad del sustrato

Background: Xeric forests dominated by two tree species, Scutia buxifolia (Rhamnaceae) and Celtis tala (Ulmacea), are temperate, semi-deciduous wooded communities that represent the most abundant woodlands on the eastern plains of Buenos Aires Province, Argentina. The district of Magdalena has one of the most well-preserved native-forest areas, with an environmental heterogeneity that gives rise to the wide variability in the vegetation present. Aims: The aim of this study was to analyze the species composition, diversity, seasonal variations, and substrate specificity of anamorphic fungi (Ascomycota) on the green leaves and in the leaf litter of native forests dominated by Scutia buxifolia and Celtis tala from Magdalena, Buenos Aires, Argentina. Methods: In order to obtain the mycobiota of decomposition, seasonal samples of green leaves and leaf litter from both types of trees were collected over a two-year period. In the laboratory, the leaves were placed in a moist chamber and incubated at room temperature. Results: A total of 100 species of anamorphic Ascomycota were identified in both forests. No significant variations were observed in the richness, diversity, or evenness of the fungal communities of the green leaves and leaf litter of both forests between seasons. Conclusions: The species that characterized the fungal communities in the leaves of each of the trees were found to be different. The type of substrate had a stronger influence in determining the composition of the fungal community in both types of forests (AU)

Antecedentes: Los bosques xerófilos dominados por las especies arbóreas Scutia buxifolia (Rhamnaceae) y Celtis tala (Ulmaceae) conforman comunidades boscosas semicaducas y templadas que constituyen los bosques nativos más abundantes de la provincia de Buenos Aires, Argentina. En el distrito de Magdalena constituyen una de las comunidades naturales de este tipo mejor conservada, con una heterogeneidad ambiental que da lugar a la gran variabilidad en la composición de la vegetación presente. Objetivos: El objetivo del presente trabajo fue analizar las distribución de especies, la diversidad, las variaciones estacionales y la especificidad por el sustrato de hongos anamórficos (Ascomycota) presentes en las hojas verdes y en la hojarasca de los bosques nativos xerófilos dominados por las especies arbóreas Scutia buxifolia y Celtis tala en el partido de Magdalena, provincia de Buenos Aires, Argentina. Métodos: Para obtener la micobiota descomponedora se tomaron muestras estacionales de hojas verdes y hojarasca de los 2 tipos de árboles durante un período de 2 años. En el laboratorio, las hojas se colocaron en cámara húmeda y se incubaron a temperatura ambiente. Resultados: Se identificaron 100 especies de anamorfos de la división Ascomycota en las hojas de ambos tipos de árboles. No se observaron diferencias en cuanto a la diversidad, equidad y riqueza de especies entre ambos tipos de hojas. Conclusiones: Las especies que componen la comunidad fúngica de las hojas de Scutia buxifolia y Celtis tala es diferente. El tipo de sustrato que representan las hojas de cada especie arbórea condiciona la composición de la comunidad de anamorfos de Ascomycota presentes en ambos tipos de hoja (AU)