Browsing by Author "Villa, Maria"
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- Abundance and diversity of potential vectors of Xylella fastidiosa in four different wine regions of PortugalPublication . Rodrigues, Isabel; Pereira, Luís Fernando; Villa, Maria; Santos, Sónia A.P.; Baptista, Paula; Pereira, J.A.Xylella fastidiosa, is a phytopathogenic bacterium, responsible for serious diseases in important crops, such as Pierce’s Disease in grapevines. The recent detection of this bacterium in Portugal is worrying, since this bacterium can spread rapidly via xylem-sap feeder insects, mainly belonging to Hemiptera Cicadomorpha. In this context, the goal of this work was to detect the abundance and diversity of possible vectors of X. fastidiosa in vineyards from different wine regions of Portugal. For that, in 2018, 21 vineyards with ground cover and from four different wine regions of Portugal (i.e., “Trás-os-Montes”, “Vinho Verde”, “Bairrada”, and “Peninsula de Setúbal”) were sampled for adults of Auchenorrhyncha, during three distinct periods (beginning of July, mid September and mid October). Sampling was performed in the ground and in the aerial part of the vines. In each sampling date, 10 samples of 10 sweepings were collected on the ground in each vineyard. On the aerial part of the vines, 10 samples of 50 sweepings were collected in 3 lines of the vineyard. A total of 3543 Cicadomorpha were collected on the 3 sampling dates, being the highest abundance observed in the mid September. The “Trás-os-Montes” and “Bairrada” regions, in general, presented the highest abundance of insects of this infraorder, but it was in “Vinho Verde” region that there was a highest abundance of potential vectors: Philaenus, Neophilaenus and Cicadelli viridis.
- Abundance of spittlebug nymphs (Hemiptera: Aphrophoridae) in Trás-osMontes region, PortugalPublication . Rodrigues, Isabel; Villa, Maria; Baptista, Paula; Pereira, J.A.Spittlebugs (Hemiptera: Aphrophoridae) are considered the main European vector of Xylella fastidiosa, a gram-negative bacterium responsible for serious diseases in important agronomic crops. Nymphs of spittlebugs develop in vegetation cover where they produce a spittle mass that provides protection from natural enemies and solar radiation. This spittle mass is visible to the unaided eye which facilitates its monitoring, the understanding of nymph’s dynamics and the implementation of control strategies against X. fastidiosa. In this context, the goals of this work were monitoring the abundance of spittlebug nymphs and identifying the host plants in the natural ground cover in the Trásos-Montes region, Portugal. For that, the presence, number of spittles per plant, number of nymphs per spittle, and spittle position low, medium or high were recorded over a sample unit of 100 × 25 cm in one olive grove (spring 2017 and 2018), in one almond orchard and one vine (spring 2018) from Trás-os-Montes. Thirty sample units randomly distributed over a transect covering 1 ha were selected per sampling date and sampling site. The peak of spittlebug nymphs occurred in the middle of April and first weeks of May in 2017 and 2018, respectively, in all sampling sites. Nine spittle masses and a mean of 1.93 ± 0.35 plants with spittle per m2 were recorded respectively in 2017 and 2018. In 2017, Crepis vesicaria L. and Bromus diandrus Roth were the most attacked species. In 2018, the presence of nymphs of the genus Neophilaenus was more abundant in the vine, presenting a mean of 0.60 ± 0.19 nymphs per m2, while Philaenus nymphs showed a higher abundance in the olive grove, presenting a mean of 0.17 ± 0.08 nymphs per m2. Nymphs of the genus Neophilaenus were identified with high frequency in the species Avena barbata subsp. lusitanica (Tab. Morais) Romero Zarco and Cynodon dactylon (L.) Pers and the Philaenus nymphs were identified more frequently in the species Erodium cicutarium (L.) L´Her. and in the genus Trifollium spp. It was verified that the number of nymphs registered in the Trás-os-Montes region was much lower than the numbers reported in other European regions, being necessary more years of study to understand the dynamics of spittlebug nymphs.
- Abundância e diversidade da ordem Coleoptera em vinhas de diferentes regiões vinícolas de PortugalPublication . Taranto, Luisa; Rodrigues, Isabel; Villa, Maria; Pereira, J.A.Os insetos da ordem Coleoptera desempenham um papel fundamental na manutenção e incremento da sustentabilidade dos ecossistemas agrários, ao servir de suporte a relevantes serviços ecossistémicos. Atualmente, são o maior grupo de insetos já descritos e estão presentes em quase todos os ambientes agrícolas. Na vinha, os coleópteros podem ocupar diferentes nichos ecológicos, a destacar a ação predadora de algumas famílias que se alimentam de pragas importantes da videira. Neste sentido, no presente trabalho procedeu-se à avaliação da abundância e diversidade das famílias de coleópteros na copa da videira e no coberto vegetal do solo de vinhas de diferentes regiões vinícolas portuguesas nomeadamente Região Demarcada do Douro, Bairrada, Beira Interior, Península de Setúbal, Trás-os-Montes e Vinhos Verdes. Para tal, em 2019, em três períodos distintos (julho, setembro e outubro) procedeu-se à amostragem de 36 vinhas dispersas nas diferentes regiões vinícolas. Em cada parcela, foram colhidas 20 amostras, 10 na copa da videira e 10 no coberto vegetal, utilizando a técnica de varredura. No total foram capturados 2954 indivíduos pertencentes a 36 famílias de Coleoptera. As famílias mais abundantes foram Chrysomelidae, Coccinellidae e Latridiidae. Os resultados apontam para uma maior abundância e diversidade de Coleoptera na Região Demarcada do Douro. Em todas as regiões vinícolas, o maior número de indivíduos foi observado no coberto vegetal em julho. O coberto vegetal mostrou ser uma zona importante de Coleoptera, provavelmente, uma vez que possui fontes alternativas de alimento, maior humidade e pode servir de abrigo para a presença destes artrópodes.
- Abundância e diversidade de coleópteros em olivais transmontanosPublication . Rodrigues, Isabel; Villa, Maria; Reis, Carlos; Pereira, J.A.Os coleópteros, desempenham um papel importante no funcionamento dos agroecossistemas, uma vez que participam em processos ecológicos importantes como por exemplo a decomposição de matéria orgânica e reciclagem de nutrientes, e a regulação das populações de plantas e animais, entre outros. Pelo que o conhecimento da diversidade deste grupo taxonómico é da maior importância numa perspetiva de produção integrada de culturas. No olival os coleópteros podem ocupar diferentes nichos ecológicos, sendo de destacar a ação predadora de algumas famílias como contra pragas importantes da cultura. Neste sentido, com o presente trabalho pretendeu-se avaliar a abundancia e diversidade das famílias de coleópteros do olival na região de Trás-os-Montes. Assim, ao longo de dois anos distintos, 2012 e 2013, recorrendo à técnica de pancadas, com periodicidade semanal, de fevereiro a dezembro, foram amostrados quatro olivais. No total foram identificadas 27 famílias de coleópteros, que apresentaram variações ao longo do ano e entre anos. Sendo as famílias Scraptidae e Phalacridae as mais abundantes ao longo dos dois anos de amostragem. Em 2012, a família Coccinelladae apresentou elevada abundancia, sendo que várias espécies desta família desempenham papel importante na limitação natural de pragas do olival. Outras famílias de coleópteros predadores com Carabidae, Stafilinidae foram também observadas, mas com baixa abundância. A análise do número total de exemplares mostrou uma elevada variação anual, sendo a sua abundância muito superior em 2012.
- Abundância e diversidade de formigas na copa da oliveira em olivais de Trás-os-MontesPublication . Reis, Carlos; Villa, Maria; Rodrigues, Isabel; Ruano, Francisca; Pereira, J.A.As formigas (Hymenoptera; Formicidae) ocupam diferentes nichos ecológicos com um papel importante no funcionamento e dinâmica dos agroecossistemas. No olival apresentam uma dupla ação, se por um lado podem contribuir para a limitação natural de algumas pragas, como é o caso da traça-da-oliveira, pelo consumo de ovos e larvas, por outro podem diminuir predação e o parasitismo de algumas pragas, estabelecendo relações mutualistas com pragas como a cochonilha-negra e diminuindo desta forma a limitação natural da praga. Neste sentido, com o presente trabalho pretendeu-se estudar a abundância e diversidade de formigas na copa da oliveira em diferentes olivais de Trás-os-Montes. O trabalho decorreu em dois anos distintos, 2012 e 2013, em quatro olivais da região de Mirandela, onde semanalmente desde abril a dezembro se procedeu à abanadela de ramos em 25 árvores/olival. O material recolhido foi transportado para laboratório separado pelos diferentes grupos taxonómicos e as formigas identificadas ao nível e espécie. No total foram identificadas 10 espécies de formigas, nomeadamente, Camponotus cruentatus (Latreille), Camponotus fallax (Nylander), Camponotus lateralis (Olivier), Camponotus piceus (Leach), Cataglyphis hispanicus (Emery), Cataglyphis ibericus (Emery), Crematogaster scutellaris (Olivier), Formica rufibarbis Fabricius, Tapinoma complexo nigerrimum (Nylander) e Tapinoma madeirense Forel. A abundância e diversidade variaram nos dois anos e ao longo do ano. Algumas das espécies encontradas têm sido referidas como importantes agentes de limitação natural de pragas da oliveira.
- Análisis de supervivencia de Ageniaspis fuscicollis (Dalman), parasitoide de la polilla del olivoPublication . Villa, Maria; Santos, Sónia A.P.; Pereira, J.A.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.
- Aphrophoridae dynamic and feeding preference for plants in natural ground cover in olive groves from Trás-os-MontesPublication . Villa, Maria; Reis, Carlos; Rodrigues, Isabel; Baptista, Paula; Pereira, J.A.Xylella fastidiosa was recently detected in several regions of Europe. This phytopathogenic bacterium infects multiple plants species, among them important crops such as the olive tree. Insects belonging to Aprophoridae are the main potential vectors of X. fastidiosa in Europe. These insects are in general highly polyphagous, however they may prefer different plant species or families of plants. Currently X. fastidiosa has not been detected in Portugal but constitutes a serious risk since has been recently found in several regions from the Iberian Peninsula. Particularly, the olive orchard suffers important damages in other regions from Europe and the knowledge about potential vectors dynamics and feeding preferences is crucial for establishing prevention and control strategies. In this context, the preference for plants in natural ground cover and the dynamic of Aphrophoridae nymphs in olive orchards from Portugal was studied. The work was accomplished during springs 2017 and 2018 in two olive orchards. One of them was partially burned in 2016 and presented natural ground cover vegetation abnormally vigorous and the other was under integrated production. The number of plants with foams, the number of foams per plant, its position in the plant and the number of nymphs per foam were recorded. More than 90 plant species belonging to around 18 plant families were identified. One year after the fire, in 2017, more than 85% of the foams were observed in the post-fire orchard, with more ground cover by Fabaceae and less by Poaceae than the integrated orchard. In 2018 the Aphrophoridae abundance dramatically decreased. Foams were found mainly in plants belonging to Asteraceae and Fabaceae. Several plant families never presented foams. The obtained results will allow design a more efficient management of the vegetation ground cover with the goal of decrease the risk of infection with X. fastidiosa in Portuguese olive orchards.
- Are surrounding patches barriers for Prays oleae (Bernard) in the olive agroecosystem?Publication . Villa, Maria; Santos, Sónia A.P.; Pereira, J.A.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.
- Biodiversity and pollen feeding habits of syrphids in olive groves and surrounding landscape in Northeastern Portugal during springPublication . Villa, Maria; Santos, Sónia A.P.; Marrão, Rosalina; Pinheiro, Lara Alina; López-Sáez, José António; Aguiar, Carlos; Pereira, J.A.Many syrphid larvae are predators of aphids and early stages of moths and psyllids, being potential control agents of some olive pests. However, adults need pollen and nectar for energy and reproduction. An increase of plant resources biodiversity in heterogeneous landscape could benefit these natural enemies. Thus, our goal of was to study the syrphid biodiversity and their pollen sources in olive agroecosystems from the northeast of Portugal during spring, that coincides with the availability of pests. For that, syrphids were captured in three not-tilled olive groves and two surrounding field areas (an herbaceous vegetation patch and a scrubland) next to each olive grove. Simultaneously, flowering plant inventories were carried out. Syrphids and the pollen contained in the guts of the most abundant species were identified. Thereafter pollen in guts was compared with pollen in the environment to evaluate a potential pollen selection. The most abundant species were Sphaerophoria scripta and Melanostoma mellinum. During the spring syrphids did not consume all the occurring plant species but did not actively selected pollen types. Results indicated that Asteraceae, Plantaginaceae, Caryophyllaceae, Echium type, Rumex type and Jasione type are important food sources for M. mellinum and S. scripta. These results will allow managing ground cover vegetation more efficiently in order to conserve syrphids in the olive agroecosystem.
- Biodiversity and pollen feeding habits of syrphids in olive groves and surrounding landscape in Northeastern Portugal during springPublication . Villa, Maria; Santos, Sónia A.P.; Marrão, Rosalina; Pinheiro, Lara Alina; López-Sáez, José António; Aguiar, Carlos; Pereira, J.A.Many syrphid larvae are predators of aphids and early stages of moths and psyllids, being potential control agents of some olive pests. However, adults need pollen and nectar for energy and reproduction. An increase of plant resources biodiversity in heterogeneous landscape could benefit these natural enemies. Thus, our goal of was to study the syrphid biodiversity and their pollen sources in olive agroecosystems from the northeast of Portugal during spring, that coincides with the availability of pests. For that, syrphids were captured in three not-tilled olive groves and two surrounding field areas (an herbaceous vegetation patch and a scrubland) next to each olive grove. Simultaneously, flowering plant inventories were carried out. Syrphids and the pollen contained in the guts of the most abundant species were identified. Thereafter pollen in guts was compared with pollen in the environment to evaluate a potential pollen selection. The most abundant species were Sphaerophoria scripta and Melanostoma mellinum. During the spring syrphids did not consume all the occurring plant species but did not actively selected pollen types. Results indicated that Asteraceae, Plantaginaceae, Caryophyllaceae, Echium type, Rumex type and Jasione type are important food sources for M. mellinum and S. scripta. These results will allow managing ground cover vegetation more efficiently in order to conserve syrphids in the olive agroecosystem.