Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is commonto overcome this problem by means of either slow movements or physical adaptations of the robot at the contact pointwith the walking surface in order to increase the frictional characteristics. In the case of slipping, several types ofsensors have been used to identify the relative displacement at the contact point of the supporting leg with the walkingsurface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as ameasurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates,the force measurement at the contact point is used to obtain the total displacement at the supporting point due to thelow-friction conditions. This is an important issue when an accurate Cartesian task is required

Effect of different plant species and temperatures on the survival of Philaenus spumarius

The spittlebug Philaenus spumarius (L.) has been identified as vector for the damaging bacterium X. fastidiosa in Europe. The knowledge about this insect biology and survival developing on native plants from Europe is crucial to establish ground cover management strategies in olive orchards to control the X. fastidiosa spread. In this study we aimed to evaluate the survival of adults developing on two native and common plants in Europe as well as the effect of different temperatures on the P. spumarius survival. The species selected for the survival analysis were Medicago arabica (L.) Huds. and Sanguisor baverrucosa (Link exG.Don) Ces. These plants are distributed all across Europe and presented foams near the campus, where they were collected. New born adults (<24h) were used for survival analysis. Six treatments (M. sativa 21⁰C, M. sativa 25⁰C, S. verrucosa 21⁰C, water 21⁰C, water 25⁰C and water 4⁰C) with 21 to 30 replicates were accomplished. Results indicated that survival of P. spumarius could improve when developing on different plants species. Variation in temperatures also affected the P. spumarius survival, being particularly remarkable the improvement of survival under 4⁰C when compared with the other water treatments.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N. 727987 “Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy XF-ACTORS”.info:eu-repo/semantics/publishedVersio

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

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

The surrounding landscape shapes the abundance of Sphaerophoria scripta and Melanostoma mellinum (Diptera: Syrphidae) in Portuguese vineyards

1. The intensification of urban and agricultural use in the landscape is the major driver of biodiversity loss and the consequent decrease of ecosystem services provided by insects. Syrphids are important ecosystem service providers, including pest regulation, pollination, and matter decomposition. 2. Understanding how the surrounding landscape to crops affects syrphids is essential to implementing strategies to reverse the negative effects of the agricultural landscape’s simplification. 3. This study describes the Syrphidae community in Portuguese vineyards and the response of the most abundant species, Sphaerophoria scripta Linnaeus, 1758, and Melanostoma mellinum Linnaeus, 1758, to the landscape composition and configuration within a gradient of distances (500, 1000, and 2000 m) from the sampled vineyards. 4. The presence of seminatural habitats and other crops in the surrounding landscape increased both species at the largest distance, whereas the presence of artificial territory, olive orchards, and vineyards reduce M. mellinum at some of the buffers. 5. Increasing seminatural habitats in the vineyards surrounding landscape (2000 m) and, potentially, introducing nature-friendly practices in the principal crops around vineyards may favour syrphid abundance.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), and to the Associate Laboratory SusTEC (LA/P/0007/2020); Isabel Rodrigues acknowledges the PhD grant (2020.07051.BD) provided by FCT.info:eu-repo/semantics/publishedVersio

Análisis del pedaleo ciclista con sistemas convencionales VS no circulares en pruebas submáximas y supramáximas

El objetivo de este trabajo ha sido analizar y comparar el rendimiento mecánico máximo (pruebas supramáximas) y la eficiencia energética (pruebas submáximas) desarrollada por ciclistas profesionales con un sistema de pedaleo convencional (C) y con un sistema de pedaleo no circular (Sistema Rotor® o SR); así como valorar sus efectos en la cinemática del pedaleo. 15 ciclistas profesionales realizaron varias pruebas submáximas y supramáximas, con un sistema C y con 4 variantes del SR. Los datos de eficiencia energética obtenidos en el estudio fueron similares a los descritos en otros trabajos, sin diferencias entre C y SR, aunque sí se alteró la cinemática del pedaleo del tobillo y la rodilla. Las variables de rendimiento mecánico máximo fueron mayores con SR, lo que parece indicar que estos sistemas pudieran incrementar el rendimiento en las modalidades de Ciclismo en Pista.Peer Reviewe

Predatory potential of two functional groups of spiders on Philaenus spumarius

There is an urgent need of increasing the knowledge about natural enemies of Philaenus spumarius and finding strategies to limit the spread of X. fastidiosa. Generalist predators, such as spiders, can arise as potential natural control agents. Determining the functional response is crucial for understanding the potentiality of a predator as biological control agent. In this work, the functional response of two widespread palearctic spider species belonging to two different functional groups was assessed. The ambusher spider Synema globosum and the orb-weaver Araniella cucurbitina were used as model species and P. spumarius as prey under laboratory conditions. In parallel, Ceratitis capitata was also used as prey in order to compare the spiders´ predatory potential between a non-flying insect (P. spumarius) and a flying one (C. capitata). A. cucurbitina and S. globosum showed a type II and type I functional response respectively when fed with P. spumarius and a type II response when fed with C. capitata. Both the handling time and attack rate were significantly different between spider species when fed with P. spumarius (p<0.01) and between prey types for each spider functional group (p<0.01). The results suggest that S. globosum was more efficient capturing spittlebugs one by one than A. cucurbitina. On the contrary, A. cucurbitina was more efficient killing flies in webs than S. globosum.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N. 727987 “Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy XF-ACTORS”.info:eu-repo/semantics/publishedVersio

Plants biodiversity in olive orchards and surrounding landscapes from a conservation biological control approach

Many natural control agents of olive pests need pollen and nectar from non-crop plants in order to complete their life cycles. However, a deep knowledge about the occurring plant species in the agroecosystem is necessary to select the plant species to be maintained or enhanced from a conservation biological control approach. Thus, in this study, the goal was to increase the understanding about the plants’ biodiversity in an important olive-producing region in the northeast of Portugal. For that, on a weekly basis during the spring and every other week in the summer and autumn, blooming plant inventories were accomplished in three olive orchards with spontaneous vegetation and its surroundings (woody and herbaceous vegetation areas) from April to December of 2012 and 2013. The percentage ground cover for each flowering plant species was recorded following the Daubenmire cover scale modified by Bailey. A total of 258 plant species belonging to 47 families were identified. The most abundant family was Asteraceae, followed by Poaceae, Fabaceae and Brassicaceae. Several species were specific to each land use and presented different flowering periods, representing a potential variety of food sources across the seasons. Additionally, some of the identified species are known for their implications as providers of the key requisites for natural control agents. These results provided us with valuable information for the implementation of conservation biological control measures.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT to CIMO (UIDB/00690/2020). National funding by FCT, through the individual postdoc grant (SFRH/BPD/119487/2016) (María Villa).info:eu-repo/semantics/publishedVersio

Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) Larvae on Saissetia oleae (Olivier) (Hemiptera: Coccidae): implications for biological control

Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a voracious predator of soft-bodied insects such as juveniles of scale insects and the black scale Saissetia oleae (Olivier) (Hemiptera: Coccidae) is an important pest of several crops, such as the olive tree. However, the predatory effciency of C. carnea on S. oleae has been unstudied yet. The present work aimed to study the functional response of larvae of C. carnea fed on S. oleae nymphs. In a controlled laboratory environment, increasing densities of S. oleae second and third nymph stages were offered to newly emerged specimens of the three larvae instars of C. carnea. After 24 h, the number of killed S. oleae was recorded and the functional response of C. carnea was assessed. The three larval stages of C. carnea displayed a type-II functional response, i.e., killed prey increased with higher S. oleae densities up to a maximum limited by the handling time. The attack rate did not significantly differ among the three instars while the maximum attack rate was significantly higher for the third instar. The handling time of the first larval instar of C. carnea was higher than that of the third instar. Our results demonstrated that S. oleae could act as a food resource for all larval stages of C. carnea. Furthermore, the third larval stage of the predator was the most effcient in reducing S. oleae densities. These results suggest that C. carnea larvae could contribute to S. oleae control in sustainable agriculture.This research was funded by Foundation for Science and Technology (FCT, Portugal), grant number UIDB/00690/2020. Abdelkader Meni Mahzoum was supported by Erasmus+ Programme, Mare Nostrum Project with reference 2016-1-PT01-KA107-022660. María Villa thanks FCT for the PostDoc grant SFRH/BPD/119487/2016info:eu-repo/semantics/publishedVersio

Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Saissetia oleae (Olivier) (Hemiptera: Coccidae)

Lacewings are common biocontrol agents against a wide range of agricultural pests.These predators are highly voracious against soft-bodied preys such as juveniles of scale insects. In this context, the present work aims to study the use of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) as biological control agent against Saissetia oleae (Olivier) (Hemiptera: Coccidae). For that, we studied the functional response of the larval instars of C. carnea to nymphs of S. oleae. Increasing densities (3, 5, 10, 15, 25 and 40) of S. oleae nymphs were offered to the three larval stages of C. carnea in a controlled laboratory environment. After 24 hours, the number of S. oleae consumed by C. carnea larva was recorded and the functional response calculated. The three larval stages of C. carnea displayed a type II functional response behavior. Prey consumption by C. carnea larvae increased with high S. oleae densities. Moreover, younger larvae showed a lower predation rate in comparison with the older ones. The search rate and handling time of the third instar larvae were lower than those of the younger larval instars, and the simulated max. attack rate of the third instar larvae was higher than those of the first and second instar larvae. Our results suggest that all larval stages of C. carnea could be important in S. oleae biological control in olive orchards, although the third larval stage of the predator was more efficient in reducing S. oleae densities than first and second C. carnea larval instars.info:eu-repo/semantics/publishedVersio