Which Seed Properties Determine the Preferences of Carabid Beetle Seed Predators?

Ground beetles are important invertebrate seed predators in temperate agro-ecosystems. However, there is a lack of information regarding which seed properties are important to carabids when they select seeds for consumption. Therefore, seed properties, such as size, shape, morphological defence, and chemical composition, were measured, and in addition to seed taxonomy and ecology, these data were used to explain carabid preferences. Carabid preferences were assessed using a multi-choice experiment with 28 species of weed seeds presented to 37 species of Carabidae. Multiple regression on distance matrices (MRM) was used to determine the importance of particular sets of seed properties for carabids. The analysis was conducted for the full set of carabids (37 species) as well as for subsets of species belonging to the tribes of Harpalini or Zabrini. For the complete set of species, seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties significantly explained carabid preferences (proportion of explained variance, R2 = 0.465). The model for Harpalini fit the data comparably well (R2 = 0.477), and seed dimensions, seed mass and seed coat properties were significant. In comparison to that for Harpalini, the model for Zabrini had much lower explanatory power (R2 = 0.248), and the properties that significantly affected the preferences were seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties. This result suggests that the seed traits that carabids respond to may be specific to taxonomic and likely relate to the degree of specialisation for seeds. This study contributes to understanding the mechanisms that determine the preferences of carabid beetles for seeds.

The resilience of weed seedbank regulation by carabid beetles, at continental scales, to alternative prey.

Carabids are generalist predators that contribute to the agricultural ecosystem service of seedbank regulation via weed seed predation. To facilitate adoption of this ecosystem services by farmers, knowledge of weed seed predation and the resilience of seedbank regulation with co-varying availability of alternative prey is crucial. Using assessments of the seedbank and predation on seed cards in 57 cereal fields across Europe, we demonstrate a regulatory effect on the soil seedbank, at a continental scale, by groups formed of omnivore, seed-eating (granivore + omnivore) and all species of carabids just prior to the crop-harvest. Regulation was associated with a positive relationship between the activity-density of carabids and seed predation, as measured on seed cards. We found that per capita seed consumption on the cards co-varied negatively with the biomass of alternative prey, i.e. Aphididae, Collembola and total alternative prey biomass. Our results underline the importance of weed seedbank regulation by carabids, across geographically significant scales, and indicate that the effectiveness of this biocontrol may depend on the availability of alternative prey that disrupt the weed seed predation.

Ethnobotanical inventory of medicinal plants used in the Qampaya District, Bolivia / Inventario etnobotánico de plantas medicinales usadas en el Distrito Qampaya, Bolivia

Herbal medicine therapy is traditionally practiced by indigenous healers in Bolivia for hundreds years. Due to the great geographical and ecological diversity, there are thousands of native plants, which are utilized against diverse types of diseases. Nowadays, there is a worldwide problem connected with possible loss of ethnobotany knowledge because of the lack of the interest of young people. In present study, survey focused on medicinal plants used by rural people in Qampaya District, Potosí Department, Bolivia has been done. The data were collected from 60 respondents by semi-structured interviews. The results showed that 60 plant species belonging to 30 families are known as curative plants in this area. The mostly named families were Asteraceae (14 species) followed by Lamiaceae (7 species) and Brassicaceae (4 species). Predominant health problems treated by these plants are urological problems and gastro-intestinal disorders. The most frequently used plant parts were leaves and the preparation is mostly done as infusion. Even though the knowledge of using medical plants plays important role in life of Bolivian rural people, which use plants as medicines against various types of diseases, this study showed that 25 percent of respondents didn’t know any medicinal plants. On the other hand 40 percent of asked people have known 6 or more medicinal plant species.

La terapia de la medicina herbolaria es practicada, tradicionalmente, por los curanderos indígenas en Bolivia, desde hace cientos de años. Gracias a la gran diversidad geográfica y ecológica, hay miles de plantas nativas, que se utilizan para el tratamiento de diferentes tipos de enfermedades. Hoy en día, hay un problema mundial relacionado con la posible pérdida del conocimiento etnobotánico, esto debido a la falta de interés de las nuevas generaciones. El presente estudio descriptivo, mediante una encuesta, fue enfocado a las plantas medicinales utilizadas por la población rural del Distrito Qampaya, Departamento de Potosí, Bolivia. Los datos se obtuvieron de 60 informantes mediante una encuesta semiestructurada. Los resultados mostraron que 60 especies de plantas medicinales. pertenecientes a 30 familias botánicas, son conocidas en el área de intervención. Las familias botánicas, más importantes de uso medicinal son Asteraceae (14 especies), seguido de Lamiaceae (7 especies) y Brassicaceae (4 especies). Los problemas predominantes de salud, tratados con estas especies, son los urológicos y trastornos gastrointestinales. La parte de la planta más utilizada son las hojas y la forma más común de uso es en infusión. A pesar de que el conocimiento sobre la utilización de las plantas medicinales, juega un papel importante en la vida de la población rural de Bolivia, quienes utilizan las plantas medicinales para el tratamiento de diversos tipos de enfermedades, este estudio mostró que el 25 por ciento de los encuestados no tienen conocimiento sobre la utilidad medicinal de ninguna especie vegetal. Por otro lado, el 40 por ciento de los informantes conocen 6 o más especies de plantas medicinales.