Understanding insect foraging in complex habitats by comparing trophic levels: insights from specialist host-parasitoid-hyperparasitoid systems

Insects typically forage in complex habitats in which their resources are surrounded by non-resources. For herbivores, pollinators, parasitoids, and higher level predators research has focused on how specific trophic levels filter and integrate information from cues in their habitat to locate resources. However, these insights frequently build specific theory per trophic level and seldom across trophic levels. Here, we synthesize advances in understanding of insect foraging behavior in complex habitats by comparing trophic levels in specialist host-parasitoid-hyperparasitoid systems. We argue that resources may become less apparent to foraging insects when they are member of higher trophic levels and hypothesize that higher trophic level organisms require a larger number of steps in their foraging decisions. We identify important knowledge gaps of information integration strategies by insects that belong to higher trophic levels

Dimensional and morphological analysis of the detritus from six european wood boring insects

Detailed morphological and dimensional analysis of the detritus deposited in the galleries of woodboring insects was performed for some of the most common xylophagous insect larvae in timber construction in Spain. The samples studied belong to six species of four common families of borers:Cerambycidae, Anobiidae, Curculionidae and Lyctidae. The samples were provided by Spanish and German companies and laboratories. The detritus was assessed for size, shape, and colour and, for different species, was found to show morphological and dimensional differences, enabling betterand faster identification of these destructive agents. Frass shape and colour assessment together with statistical dimensional data of the six species are presented. A predictive function based on length and width variables of the detritus is proposed, using multivariate discriminant analysis methodology. This function has been proven to be more than 78% effective in tests of the model

In vitro testing of alternative synthetic and natural antiparasitic compounds against the monogenean sparicotyle chrysophrii

Gill monogenean Sparicotyle chrysophrii is considered the most detrimental fish parasite to the Mediterranean aquaculture. Treatment of sparicotylosis relies on frequent gill inspections correlated with the seasonal increase in seawater temperature, application of functional feeds, and treatments with formalin baths where permitted. While the latter is bound to be banned in Europe, other synthetic anthelminthics, such as praziquantel and ivermectin, are prone to induce resistance in the parasites. Therefore, we investigated, in vitro, 14 synthetic and natural compounds against adult S. chrysophrii, developing dose–response modelsm and estimated toxicity levels at 20%, 50%, and 80% parasite mortality. Bactericidal activity of target compounds was also tested in two important aquaculture bacteria; Vibrio harveyi and V. anguillarum, while their potential host toxicity was evaluated in gilthead seabream SAF-1 cell line. Synthetic compound bithionate sodium exerted the most potent toxicity against the monogenean, no host cytotoxicity, and a medium and high potency against two bacterial pathogens. In comparison, target natural compounds were approximately 20 (cedrol) or up to 154 times (camphor) less toxic for the monogenean. Rather than completely dismissing natural compounds, we suggest that their application in combination with synthetic drugs, especially if administered in the feed, might be useful in sparicotylosis treatment

Adaptive Interaction of Persistent Robots to User Temporal Preferences

Abstract. We look at the problem of enabling a mobile service robot to autonomously adapt to user preferences over repeated interactions in a long-term time frame, where the user provides feedback on every interaction in the form of a rating. We assume that the robot has a discrete and finite set of interaction options from which it has to choose one at every encounter with a given user. We first present three models of users which span the spectrum of possible preference profiles and their dynamics, incorporating aspects such as boredom and taste for change or surprise. Second, given the model to which the user belongs to, we present a learning algorithm which is able to successfully learn the model parameters. We show the applicability of our framework to personalizing light animations on our mobile service robot, CoBot.

Efecto de las gemas en la resistencia a flexión de piezas enterizas de madera

A theoretical analysis is conducted to determine the effect of wanes on the bearing capacity of timber in light of the reduction they entail in cross-sectional area compared to fully rectangular sections. The concomitant loss of bending strength is likewise evaluated. Parallel tests are run on 84 samples —51 with wanes— of large section, Scotch (Pinus sylvestris L.) and Corsican (Pinus pinaster Ait.) pine beams taken from old buildings. The bending strength, modulus of elasticity and density are found in accordance with European standard EN 408. The mechanical properties of the specimens with and without wanes are found to be very similar, and no statistically significant differences are recorded. The effect of the decline in section may be offset by greater continuity of surface fibers and the section shape effect. One practical consequence of this finding is that (within certain limits) wanes may be disregarded when grading large section timber beams in existing structures, where this flaw is very common; this in turn would reduce the high percentage of rejected beams imposed by the present visual grading standards.Se ha realizado un análisis teórico del efecto de las gemas en la capacidad resistente de vigas de madera debida a la disminución de la sección con respecto a la sección rectangular, evaluando la pérdida de resistencia a flexión equivalente. Por otro lado, se han ensayado 84 piezas de pino silvestre (Pinus sylvestris L.) y pino pinaster (Pinus pinaster Ait.) de gruesa escuadría procedente de edificios antiguos, de las que 51 presentaban el defecto de las gemas. Se ha obtenido la resistencia a flexión, el módulo de elasticidad a flexión y la densidad mediante ensayo según norma EN 408.Las propiedades mecánicas de las piezas con gemas y sin gemas resultan muy similares y no hay diferencias estadísticamente significativas. El efecto de pérdida de sección debida a la gema parece compensarse con la mayor continuidad de las fibras en la superficie de la pieza y con un efecto de forma de la sección. Una consecuencia práctica que se deriva de este hecho es que podrían despreciarse las gemas (hasta un límite) en la clasificación de piezas de madera de gruesa escuadría en estructuras existentes, donde es muy frecuente este defecto, evitando el elevado rechazo que implica la aplicación de las normas actuales de clasificación visual