Herbivores, saprovores and natural enemies respond differently to within-field plant characteristics of wheat fields

Understanding ecosystem functioning in a farmland context by considering the variety of ecological strategies employed by arthropods is a core challenge in ecology and conservation science. We adopted a functional approach in an assessment of the relationship between three functional plant groups (grasses, broad-leaves and legumes) and the arthropod community in winter wheat fields in a Mediterranean dryland context. We sampled the arthropod community as thoroughly as possible with a combination of suction catching and flight-interception trapping. All specimens were identified to the appropriate taxonomic level (family, genus or species) and classified according to their form of feeding: chewing-herbivores, sucking-herbivores, flower-consumers, omnivores, saprovores, parasitoids or predators. We found, a richer plant community favoured a greater diversity of herbivores and, in turn, a richness of herbivores and saprovores enhanced the communities of their natural enemies, which supports the classical trophic structure hypothesis. Grass cover had a positive effect on sucking-herbivores, saprovores and their natural enemies and is probably due to grasses' ability provide, either directly or indirectly, alternative resources or simply by offering better environmental conditions. By including legumes in agroecosystems we can improve the conservation of beneficial arthropods like predators or parasitoids, and enhance the provision of ecosystem services such as natural pest control

Informe Final: Projecte 2020PID-UB/017

Projecte: 2020PID-UB/017En aquest projecte s’ha explorat i utilitzat les eines del paquet d’R exams per tal de generar activitats personalitzades per als alumnes de l’assignatura de Disseny d’Experiments del grau interuniversitari UB-UPC d’Estadística. El paquet exams permet crear qüestionaris que incorporen preguntes de tipus test, numèriques o una barreja d’ambdues. Mitjançant codi R es poden generar aleatòriament diferents conjunts de dades i possibles respostes de tal manera i així els qüestionaris siguin únics per a cada alumne. Una altra avantatge que ofereix el paquet exams és que en integrar-se al Moodle un cop finalitzat el qüestionari la nota queda integrada automàticament a la base de dades de qualificacions. A més, l’alumne veu immediatament la nota i quins errors ha comès i les solucions de cada resposta. Tot i que els professors no teníem experiència prèvia amb el paquet exams, no ha sigut difícil confeccionar les preguntes ni tampoc integrar-les a la plataforma del campus virtual a través del Moodle. Al contrari, aquest procés ha resultat senzill i no hem trobat cap dificultat tècnica. L’alumnat ha respost de forma positiva, i han trobat gratificant el fet de saber la nota i els errors que havien comés en acabar el qüestionari. Per aquest motiu, creiem que l’ús del paquet exams com a part de la docència de l’assignatura és molt positiva i planegem continuar usant-lo tot explorant noves funcionalitats que ofereixi aquesta eina. Per últim, pensem que la utilització d’exams es podria estendre també a altres assignatures de anàlisis de dades i d’altres graus, com de fet s’està realitzant a l’assignatura de Disseny d’Experiments i Anàlisis de Dades (DEAD) del grau de Biomedicin

Changes in flood damage with global warming in the east coast of Spain

One common approach to cope with floods is the implementation of structural flood protection measures, such as levees or flood-control reservoirs, which substantially reduce the probability of flooding at the time of implementation. Numerous scholars have problematized this approach. They have shown that increasing the levels of flood protection can attract more settlements and high-value assets in the areas protected by the new measures. Other studies have explored how structural measures can generate a sense of complacency, which can act to reduce preparedness. These paradoxical risk changes have been described as levee effect, safe development paradox or safety dilemma. In this commentary, we briefly review this phenomenon by critically analysing the intended benefits and unintended effects of structural flood protection, and then we propose an interdisciplinary research agenda to uncover these paradoxical dynamics of risk

Brassica aphid (Hemiptera: Aphididae) populations are conditioned by climatic variables and parasitism level: a study case of Triângulo Mineiro, Brazil

Cosmopolitan pests such as Brevicoryne brassicae, Lipaphis pseudobrassicae, and Myzus persicae (Aphididae) cause significant damage to Brassicaceae crops. Assessment of the important biotic and abiotic factors that regulate these pests is an essential step in the development of effective Integrated Pest Management programs for these aphids. This study evaluated the influence of leaf position, precipitation, temperature, and parasitism on populations of L. pseudobrassicae, M. persicae, and B. brassicae in collard greens fields in the Triângulo Mineiro region (Minas Gerais state), Brazil. Similar numbers of B. brassicae were found on all parts of the collard green plants, whereas M. persicae and L. pseudobrassicae were found in greatest numbers on the middle and lower parts of the plant. While temperature and precipitation were positively related to aphid population size, their effects were not accumulative, as indicated by a negative interaction term. Although Diaeretiella rapae was the main parasitoid of these aphids, hyperparasitism was dominant; the main hyperparasitoid species recovered from plant samples was Alloxysta fuscicornis. Parasitoids seem to have similar distributions on plants as their hosts. These results may help predict aphid outbreaks and gives clues for specific intra-plant locations when searching for and monitoring aphid populations.Peer ReviewedPostprint (author's final draft

Brassica aphid (Hemiptera: Aphididae) populations are conditioned by climatic variables and parasitism level: a study case of Triângulo Mineiro, Brazil

Cosmopolitan pests such as Brevicoryne brassicae, Lipaphis pseudobrassicae, and Myzus persicae (Aphididae) cause significant damage to Brassicaceae crops. Assessment of the important biotic and abiotic factors that regulate these pests is an essential step in the development of effective Integrated Pest Management programs for these aphids. This study evaluated the influence of leaf position, precipitation, temperature, and parasitism on populations of L. pseudobrassicae, M. persicae, and B. brassicae in collard greens fields in the Triângulo Mineiro region (Minas Gerais state), Brazil. Similar numbers of B. brassicae were found on all parts of the collard green plants, whereas M. persicae and L. pseudobrassicae were found in greatest numbers on the middle and lower parts of the plant. While temperature and precipitation were positively related to aphid population size, their effects were not accumulative, as indicated by a negative interaction term. Although Diaeretiella rapae was the main parasitoid of these aphids, hyperparasitism was dominant; the main hyperparasitoid species recovered from plant samples was Alloxysta fuscicornis. Parasitoids seem to have similar distributions on plants as their hosts. These results may help predict aphid outbreaks and gives clues for specific intra-plant locations when searching for and monitoring aphid populations.Peer Reviewe