Percorrer por autor "Pascual, Susana"
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- Do non-crop areas and landscape structure influence dispersal and population densities of male olive moth?Publication . Villa, Maria; Santos, Sónia A.P.; Pascual, Susana; Pereira, J.A.The permeability of the crop surroundings to pests and the landscape structure can influence pest dispersal between crop patches as well as its abundance within the crop. In this work, we analyzed the dispersal of the olive moth Prays oleae (Bernard) throughout the olive grove surroundings and their abundance within the crop following three approaches: (i) pollen grains settled on bodies of olive moths collected in olive groves were identified and compared with flora occurring on the surrounding patches; (ii) the capability of P. oleae males to penetrate non-crop patches was analyzed (iii) the effect of the landscape structure on the abundance of the three generations of the olive moth was studied. Pollen grains of scrubs and other trees occurring in the crop surroundings, such as Cistus sp., Quercus sp., Juniperus-type or Pinaceae were identified on P. oleae bodies suggesting that P. oleae penetrates into non-crop habitats. Additionally, woody and, to a lesser degree, herbaceous patches, did not constitute barriers for P. oleae. Finally, more complex and heterogeneous patches presented lower numbers of captures of P. oleae. These results give new insights into the movements of the olive moth in the olive grove surroundings and suggest that the management of non-crop areas could influence this pest abundance.
- Efecto del paisaje y del manejo del olivar sobre la polilla del olivo Prays oleae (Bernard)Publication . Villa, María; Santos, Sónia A.P.; Sousa, J. Paulo; Ferreira, Alberto; Silva, Pedro Martins; Patanita, M. Isabel; Ortega, M.; Pascual, Susana; Pereira, J.A.El manejo del paisaje y los cultivos puede constituir una herramienta importante para la implementación de estrategias de control biológico por conservación, como consecuencia de la contribución que el uso de diseños paisajísticos adecuados y la aplicación de determinados manejos pueden representar en el incremento de las necesidades y la acción de los enemigos naturales. En el presente trabajo fue realizado un estudio multi-escala sobre el efecto de la estructura del paisaje y el manejo del cultivo en la polilla del olivo, Prays oleae. Para ello, se analizó: (i) la respuesta de la plaga a la estructura del paisaje a diferentes escalas usando como variables explicativas diferentes índices de composición y configuración del paisaje previamente seleccionados; (ii) la respuesta de la plaga al manejo de olivar (integrado y orgánico). El análisis fue realizado mediante modelos aditivos generalizados mixtos. Los resultados indicaron que varios índices de composición del paisaje (índices de biodiversidad, presencia de matorrales y de otros cultivos) influenciaron negativamente la abundancia de la polilla del olivo siendo el efecto menor a escalas mayores. Sin embargo, el efecto de los índices de configuración no fue concluyente. La latitud y probablemente las diferencias climáticas se mostraron determinantes en la abundancia de la polilla del olivo. El manejo del cultivo sin embargo no afectó a la plaga. Por tanto, los diseños de la composición del paisaje a pequeña escala parecen ser cruciales para el control de la polilla del olivo. Cabe destacar que la configuración y el manejo a escalas mayores podrían ser importantes para otras plagas y enemigos naturales, debiendo tenerse en consideración en el diseño de estrategias para control biológico por conservación en olivar.
- Landscape composition and configuration affect the abundance of the olive moth (Prays oleae, Bernard) in olive grovesPublication . Villa, Maria; Santos, Sónia A.P.; Sousa, José Paulo; Ferreira, Alberto; Silva, Pedro Martins; Patanita, M. Isabel; Ortega, Marta; Pascual, Susana; Pereira, J.A.Landscape and crop management are important concepts for conservation biological control as they can influence the abundance of natural enemies. In this work we accomplished a multi-scale study focused on the effect of landscape structure and crop management on the olive moth, Prays oleae (Bernard), an important pest of the olive tree (Olea europaea L.). The olive moth was collected in different olive groves managed under organic farming and integrated production and surrounded by different landscape structures. Generalized additive mixed models were used to analyze the response of the pest to (i) landscape composition and configuration indices, (ii) the management system and (iii) pesticides applications at different scales. Results indicated that the landscape composition, through the effect of the Simpson’s diversity index, negatively influenced P. oleae abundance and that the effect was evident at larger scales. Also, the landscape configuration negatively affected P. oleae at larger scales. However, neither the crop management system nor the pesticide applications affected P. oleae abundance. This study emphasizes that the preservation or implementation of diverse and complex landscapes can contribute to maintain lower population levels of P. oleae when compared with homogenous landscape areas.
- Molecular detection of Philaenus spumarius DNA in predators gutPublication . Lantero, Ester; Villa, Maria; Benhadi-Marín, Jacinto; Pascual, Susana; Matallanas, Beatriz; Callejas, Carmen; Baptista, Paula; Pereira, J.A.X. fastidiosa is one of the most destructive pathogens of olive orchards. Its recent arrival to Europe can cause important losses, with possible drastic consequences for the sector. Philaenus spumarius (Linnaeus 1758) was identified as vector of X. fastidiosa in Europe and finding candidate natural enemies of P. spumarius is essential to design environmentally friendly control strategies against X. fastidiosa. Generalist predators, such as spiders, arise as important potential biocontrol agents. In this context, a set of species-specific primers for detecting the presence of P. spumarius DNA in the gut of predatory arthropods is being developed. All primers will be tested for checking cross-reactive amplification of arthropods DNA and evaluated in heterospecific mixes of nucleic acids. Subsequent feeding trials will be conducted using Synemaglobosum (Fabricius 1775), an important spider species in olive groves from Mirandela, Portugal. These trials will allow determining the detection efficiency of the primers designed and also they will be the starting point to detect predation in field trials. These primers therefore provide a very useful tool for screening the gut contents of potential predators of P. spumarius, and can thus reveal candidate species for this species biological control.
- Prays oleae (Bernard), its potential predators and biocontrol depend on the structure of the surrounding landscapePublication . Pascual, Susana; Ortega, Marta; Villa, MariaArthropod populations from agricultural fields sometimes depend on the surrounding landscape structure, both composition and configuration, which affects multiple life-history traits of arthropods such as resources for survival, dispersion or death risk (e.g., predation or parasitism). Moreover, the effect of the landscape may vary with the distance to the crop, depending on factors such as the organism requirements and dispersion capabilities. This work addresses the effect of landscape (at five different scales from 250 to 1500 m) on the olive moth (Prays oleae Bernard, a key pest in olive orchards), some of its most relevant natural enemies, and biological control. The two-years study in 15 olive groves in southeastern Madrid, Spain shows that landscape complexity favours control of the olive moth, P. oleae. Simple landscapes favour P. oleae attack to the crop (measured as oviposition of the anthophagous generation) and that egg predation of the carpophagous generation is in some cases enhanced in complex landscapes. Lacewings (Neuroptera: Chrysopidae) are responsible for egg predation and populations increase in complex landscapes. On the other hand, the role of pirate bugs (Hemiptera: Anthocoridae) as a biological control agent of this part of the life cycle of P. oleae was not demonstrated. They respond primarily to Euphyllura olivina (Costa) (Hemiptera: Psyllidae) populations and are more abundant in simple landscapes. Most of the significant relationships of pest attack were detected at 750–1000 m radii buffers around the sampled olive groves suggesting that this is the main activity range for adults of P. oleae anthophagous generation. In sum, our results suggest complex configurations of the landscape enhance the biological control of P. oleae through favouring lacewings and egg predation of the carpophagous generation.