Análisis de supervivencia de Ageniaspis fuscicollis (Dalman), parasitoide de la polilla del olivo

Muchos parasitoides adultos necesitan líquidos azucarados como el néctar o las melazas de insectos para garantizar su supervivencia. Ageniaspis fuscicollis es un importante parasitoide de la polilla de olivo, Prays oleae (Bernard), siendo el más abundante en la práctica totalidad de las regiones productoras de olivo. Aunque se conocen algunos detalles sobre su reproducción, existe un escaso conocimiento acerca de su supervivencia o los recursos alimenticios de los adultos. En este trabajo se realizó un análisis de supervivencia de A. fuscicollis alimentado con sacarosa, fructosa y glucosa a varias concertaciones, debida la importancia de estos compuestos como constituyentes del néctar y las melazas de insectos. Así mismo se analizó la supervivencia del parasitoide alimentado con melazas de la cochinilla negra, Saissetia oleae (Olivier 1791), y del algodón del olivo, Euphyllura olivina (Costa 1839). Los ensayos fueron realizados en cámaras climáticas con humedad y temperatura controladas (70% H.R.), siendo testadas dos temperaturas (21 y 25 ºC) en el caso de las melazas. Los azucares y la melaza de S. oleae aumentaron la supervivencia de A. fuscicollis. La melaza de E. olivina no mostró diferencias con respecto al control negativo. Así mismo, la supervivencia de A. fuscicollis fue inferior con temperaturas más elevadas. Los resultados de este trabajo sugieren que la presencia de líquidos azucarados como el néctar y las melazas de insectos en el agroecosistema olivar podrían beneficiar la supervivencia de A. fuscicollis. Sin embargo, la melaza de E. olivina parece tener características que limitan la supervivencia del parasitoide. Temperaturas podrían perjudicar la presencia del parasitoide.info:eu-repo/semantics/publishedVersio

Artrópodes predadores associados à oliveira no Planalto Mirandês

A oliveira é atacada por mais de 250 espécies fitófagas, contudo, apenas um reduzido número apresenta importância económica. A reduzida importância da maioria das espécies deve-se principalmente à acção dos factores de limitação natural, com relevância para os predadores. Com o objectivo de contribuír para o conhecimento do complexo de artrópodes predadores associados à oliveira no Planalto Mirandês, entre Março e Outubro de 2005 a 2008, realizaram-se amostragens em dois olivais, um situado no concelho de Vimioso (Campo de Víboras) e outro no de Mogadouro (Vilarinho dos Galegos). As amostragens foram efectuadas mensalmente através da técnica de pancadas, recolhendo-se cinco amostras por olival e por data de amostragem. O material recolhido foi separado e os artrópodes predadores foram contados e identificados até à ordem ou família. Os artrópodes predadores encontrados em maior número pertencem à ordem Araneae, que representaram entre 49,6% e 82,7% do total de predadores recolhidos, dependendo da data de amostragem, olival e ano, seguidos da famílias Formicidae e Coccinellidae com representatividades entre 2,1% a 35,6% e 5,9% e 20,4%, respectivamente. Os da ordem Neuroptera foram os menos abundantes e representaram entre 3,1% e 7,8% do total das capturas. Comparando os dois olivais, verificou-se que as capturas foram, na generalidade dos casos, mais elevadas em Vilarinho dos Galegos e o maior número de indivíduos capturados ocorreu em Junho e Setembro. The olive tree has more than 250 phytophagous species that potentially can attack the plant. However, only a low number of species are economically important. The reduced importance of several phytophagous species can be attributed to the action of natural control factors, with special emphasis for predators. This study aims to contribute for the knowledge of the communities of predator arthropods associated with the olive tree in Planalto Mirandês region. The experimental work took place in two olive groves that were sampled between March and October of 2005 to 2008. One olive grove was located in Vimioso (Campo de Víboras) and the other in Mogadouro (Vilarinho dos Galegos). The arthropod community was sampled by using the beating technique on an approximately monthly basis and five samples were collected per olive grove and sampling date. All captured individuals were sorted, counted and identified till order or family under a binocular microscope. The order Araneae was the group found in higher abundance with a representatively between 49.6% e 82.7% of the total collected predators, varying with the sampling date, the olive grove and the year, followed by families Formicidae and Coccinellidae with relative abundances between 2.1% to 35.6% and 5.9% to 20.4%, respectively. The order Neuroptera was the less abundant and represented between 3.1% and 7.8% of the total captures. Comparing the two studied olive groves, the number of captures was generally higher in Vilarinho dos Galegos and the number of captured individuals occurred in July and September

Are surrounding patches barriers for Prays oleae (Bernard) in the olive agroecosystem?

The increasing interest in organic products leads to a need of finding strategies for pest control free of pesticides. Conservation biological control, through habitat management, seeks to manage the environment in order to achieve pest reductions. In this context, the surrounding habitats of agroecosystems can be management in order to impede pest dispersion and for that is crucial to understand how landscape connectivity affects pest’s species. Thus, we studied the capability of Prays oleae (Bernard) to disperse through non-crop patches composed by woody and herbaceous vegetation. For that the flight activity of P. oleae was monitored in olive groves, and surrounding scrubland and herbaceous patches from the end of March to December of 2012 and 2013. Generalized Linear Models were used to analyze the abundance of P. oleae in the different patches and locations. P. oleae captures varied between years, likely because of a strong relation with the weather conditions. For the first time, landscape connectivity aspects were identified for P. oleae, being that was clearly able to disperse over scrublands and herbaceous patches. This study provides new data that contributes to the knowledge about P. oleae dynamic under adverse weather conditions and discloses new queries about the P. oleae dispersion and movement between patches.The authors are grateful to the Portuguese Foundation of Science and Technology for financial support through the project EXCL/AGRPRO/ 0591/2012 “Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions”.info:eu-repo/semantics/publishedVersio

Combining ptychographical algorithms with the Hybrid Input-Output (HIO) algorithm

AbstractIn this article we combine the well-known Ptychographical Iterative Engine (PIE) with the Hybrid Input-Output (HIO) algorithm. The important insight is that the HIO feedback function should be kept strictly separate from the reconstructed object, which is done by introducing a separate feedback function per probe position. We have also combined HIO with floating PIE (fPIE) and extended PIE (ePIE). Simulations indicate that the combined algorithm performs significantly better in many situations. Although we have limited our research to a combination with HIO, the same insight can be used to combine ptychographical algorithms with any phase retrieval algorithm that uses a feedback function

Effects of kaolin particle films on the life span of an orb-weaver spider

Araniella cucurbitina (Araneae: Araneidae) is a widespread orb-weaver spider commonly found in agroecosystems. Mineral particle films such as kaolin, due to their protective or anti-feeding action, can represent an alternative to pesticides, especially in organic farming systems, but little is known about its effects on A. cucurbitina. Therefore, we tested the effect of kaolin sprays on the life span of A. cucurbitina under laboratory conditions. Four treatments were tested encompassing different exposure routes. Thus, kaolin sprays were applied on (i) the surface, (ii) the prey (fly), (iii) the spider and (iv) both spider & prey. A control group was tested with water in each treatment. Results showed that sprays of kaolin significantly affected the survival of A. curcubitina when applications were done on the surface and on both spider & prey registering a reduction of 48% and 56%, respectively. Spiders in control obtained higher probability of reaching alive at the end of the assay than those treated with kaolin. Differences observed can be explained by the feeding behavior of the species and may depend on the consumption of the web by the spider and the ratio spider/fly for body size.This study was financially supported by FEDER Funds throughout Programa Operacional Factores de Competitividade e COMPETE and National Funds throughout FCT e Fundação para a Ciência e Tecnologia, within the project EXCL/AGR-PRO/0591/2012: Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions (Grant number: 130390)

Interaction between affordance and handedness recognition: a chronometric study

The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation