Browsing by Author "Rebelo, Maria Teresa"
Now showing 1 - 10 of 15
Results Per Page
Sort Options
- Ancient divergence, a crisis of salt and another of ice shaped the evolution of the west Mediterranean butterfly Euchloe tagisPublication . Marabuto, Eduardo; Pina-Martins; Rebelo, Maria Teresa; Paulo, Octávio S.The Mediterranean region is an extremely complex hotspot where, since the Miocene, extensive geological, habitat and climate changes have taken place, alternating between warm and cold periods. These phenomena have taken a toll on the genetic composition of species, and surviving lineages have often adapted locally and diverged to the point of (complete) speciation. To study these phenomena, in this study we used one of the most enigmatic butterflies, the Portuguese dappled white, Euchloe tagis, a west Mediterranean endemic with fragmented, morphologically differentiated populations whose status have long been disputed. Even its affiliations with other Anthocharidini are largely unresolved. We used mitochondrial and nuclear markers under a phylogenetic and phylogeographical framework to evaluate its placement among relatives and population differentiation, reconstructing its evolutionary history. We found that this species had a Miocene origin ~15 Mya and was nearest to Euchloe s.s. and Elphinstonia. Its populations showed high genetic diversity but all coalesced to 5.3 Mya, when European and all but one African population diverged. Our multiple findings concerning the evolution of E. tagis through a changing, narrow habitable area might provide a more general perspective on how species survive within this hotspot of paramount importance.
- Challenges of Providing Safe Drinking Water in African Rural Communities: A Case Study on the Oio Region, Guinea-BissauPublication . Silveira, Pedro; Rebelo, Maria Teresa; Salvador, DanielAccess to safe drinking water is a fundamental human right, yet it remains a global challenge affecting nearly 2 billion people, particularly in Africa in regions such as Guinea-Bissau. This study investigated the microbiological and physicochemical quality of drinking water in four rural areas of the Oio region of Guinea-Bissau—Cangha N’Tchugal, Cajaque, Infaidi and Insanha—over a one-year period (October 2022–September 2023) to assess water safety and seasonal variations. During this period, eight water samples were collected and analysed from each site, split evenly between the dry and wet seasons. The results showed widespread faecal coliform contamination, with concentrations escalating during the wet season (2 to 39 CFU/100 mL), posing a health risk. Physicochemical analysis showed consistently acidic pH values (from 4.93 to 6.58) and seasonal variations in phosphate and iron concentrations, with a marked decrease in iron concentrations during the wet season. These results indicated that the water from the four sampling points was unfit for human consumption. In light of these findings, there is an urgent need for the regular monitoring of water sources used for drinking and for improved access to resources and basic sanitation in the future.
- Diagnosis of coccidiosis by Eimeria spp. in free-range chickens using Mini-FLOTAC and McMaster techniques - preliminary resultsPublication . Lozano, João; Anaya, Adriana; Rinaldi, Laura; Cringoli, Giuseppe; Gomes, Lídia; Oliveira, Manuela; Paz-Silva, Adolfo; Rebelo, Maria Teresa; Madeira de Carvalho, LuísMini-FLOTAC is emerging as a more sensitive and accurate tool to identify gastrointestinal parasites in faecal samples from domestic animals, in comparison with the McMaster method. However, research regarding its specific application in poultry samples, particularly from free-range chickens, is scarce. The current research aimed to test the use of Mini-FLOTAC for the identification of Eimeria spp. in free-range chickens and compare its results with McMaster. For this study, 40 faecal samples were collected from free-range chickens in a poultry farm located in North-Western Lisbon (Portugal). Each sample was processed with McMaster and Mini-FLOTAC techniques for the detection and count of coccidian Eimeria spp. oocysts. The resulting OPG (oocysts per gram of faeces) data obtained by the two techniques were compared using the Wilcoxon Test and correlated with the Spearman Test, and Mini-FLOTAC’s relative sensitivity was assessed, using a significance level of p<0.05. The average OPG was higher with Mini-FLOTAC and doubled the one obtained using the McMaster method (2669.3 OPG and 1220 OPG, respectively), although these results were not significant. Mini-FLOTAC’s relative sensitivity obtained in this study reached 86% (70.5-95.3%, 95%CI), although this result was not statistically significant. However, correlation of OPG counts between Mini-FLOTAC and McMaster, was significant. These preliminary results suggest the potential interest in the use of Mini-FLOTAC for the diagnosis of coccidiosis by Eimeria spp. in poultry, based on its assessment in a free-range poultry production system.
- Effects of Climatic, Chemical, and Cultural Control Strategies on Community Composition of Auchenorrhyncha and Population Dynamics of Two Major Green Leafhopper Pests in Peach OrchardsPublication . Nascimento, Patrícia Monteiro; Neto, Ana Carina; Guerreiro, Vera; Barateiro, Anabela; Anjos, Hugo; Coutinho, José Pereira; Antunes, Marília; Rebelo, Maria TeresaA three-year study in two Mediterranean peach orchards monitored Auchenorrhyncha species, including the main vectors of plant pathogens causing significant economic losses. The research focused on the management of two polyphagous leafhoppers, Asymmetrasca decedens and Hebata (Signatasca) solani. Yellow sticky traps were used to track species dynamics and assess population trends in relation to meteorological factors such as temperature, rainfall, and humidity. Chemical treatments and early green pruning were evaluated for pest control effectiveness. Fifty-five Auchenorrhyncha species were identified, including vectors of Xylella fastidiosa. H. solani appeared from spring to early summer, and was gradually replaced by A. decedens, which peaked in late summer. Higher temperatures favoured A. decedens, while rainy days significantly reduced its presence. H. solani responded less consistently to meteorological factors, but increased with higher minimum relative humidity, and decreased with higher total humidity. These results highlight the need for targeted chemical control strategies to manage A. decedens during its peak season and the benefits of early green pruning to protect susceptible trees in spring. The results emphasise the role of climate in pest dynamics and provide important insights for IPM programmes to reduce economic losses in Mediterranean peach orchards worldwide.
- Gastrointestinal parasites of free-range chickens : a worldwide issuePublication . Lozano, João; Anaya, Adriana; Palomero Salinero, Antonio; Lux Hoppe, Estevam Guilherme; Gomes, Lídia; Paz-Silva, Adolfo; Rebelo, Maria Teresa; Madeira de Carvalho, LuísGastrointestinal parasites with direct and/or indirect life cycles, namely Eimeria spp., Ascaridia galli, Heterakis gallinarum and Capillaria spp., are responsible for the most frequent and heavy economic losses in aviculture. The current review aimed to collect information about gastrointestinal parasites affecting poultry, as well as, research studies regarding parasitic diseases in free-range chicken production. From the references used in this review, 20% highlight research studies correlating prevalence of gastrointestinal parasites in free-range chickens and factors such as the production system, age and animal density, hygienic conditions and weather. Coccidiosis is responsible for the major economic losses in poultry farms. Diseases have different clinical signs and result in variable impacts on animals. Control programs include mainly vaccination, anti-coccidia and anthelminthic drugs, as well as, house cleaning and disinfection. This review concluded that coccidia and helminths are a global threat to free-range poultry production. More research in this area is necessary in order to understand the major factors influencing the prevalence of parasitic diseases in this type of poultry production. Also the search for new control strategies must be a priority, mainly using natural antiparasitic compounds and biological control approaches.
- Genomic signatures of introgression between commercial and native bumblebees, Bombus terrestris, in Western Iberian Peninsula - implications for conservation and trade regulationPublication . Seabra, Sofia G.; Silva, Sara E.; Nunes, Vera L.; Sousa, Vitor C.; Martins, Joana; Marabuto, Eduardo; Rodrigues, Ana S.B.; Pina-Martins, Francisco; Laurentino, Telma G.; Rebelo, Maria Teresa; Figueiredo, Elisabete; Paulo, Octávio S.Human‐mediated introductions of species may have profound impacts on native ecosystems. One potential impact with largely unforeseen consequences is the potential admixture of introduced with autochthonous species through hybridization. Throughout the world, bumblebees have been deliberately introduced for crop pollination with known negative impacts on native pollinators. Given the likely allochthonous origin of commercial bumblebees used in Portugal (subspecies Bombus terrestris terrestris and B. t. dalmatinus), our aim was to assess their putative introgression with the native Iberian subspecies B. terrestris lusitanicus. We analysed one mitochondrial gene, cytochrome c oxidase subunit I (COX1) and genomic data involving thousands of genome‐wide restriction‐site‐associated DNA markers (RAD‐seq). In the mitochondrial COX1 analyses, we detected one relatively common haplotype in commercial bumblebees, also present in wild samples collected nearby the greenhouses where the commercial hives are used. In the RAD‐seq analysis, we found a clear genetic differentiation between native and commercial lineages. Furthermore, we detected candidate hybrids in the wild, as well as putatively escaped commercial bumblebees, some of which being potentially fertile males. Although we cannot assess directly the fitness effects of introgressed alleles, there is a risk of maladaptive allele introgression to the local bumblebee subspecies, which can negatively impact autochthon populations. One immediate recommendation to farmers is for the proper disposal of hive boxes, after their use in greenhouses, so as to minimize the risk of escapees contaminating native populations. On the other hand, the feasibility of using local subspecies B. t. lusitanicus, preferably with local production, should be evaluated
- Genomic signatures of introgression between commercial and native bumblebees, Bombus terrestris, in western Iberian Peninsula—Implications for conservation and trade regulationPublication . Seabra, Sofia G.; Silva, Sara E.; Nunes, Vera L.; Sousa, Vitor C; Martins, Joana; Marabuto, Eduardo; Rodrigues, Ana S. B.; Pina Martins, Francisco; Laurentino, Telma G.; Rebelo, Maria Teresa; Figueiredo, Elisabete; Paulo, Octávio S.Human‐mediated introductions of species may have profound impacts on native eco ‐systems. One potential impact with largely unforeseen consequences is the potential admixture of introduced with autochthonous species through hybridization. Throughout the world, bumblebees have been deliberately introduced for crop pol ‐lination with known negative impacts on native pollinators. Given the likely alloch ‐thonous origin of commercial bumblebees used in Portugal (subspecies Bombus terrestris terrestris and B. t. dalmatinus), our aim was to assess their putative introgres‐sion with the native Iberian subspecies B. terrestris lusitanicus. We analysed one mito ‐chondrial gene, cytochrome c oxidase subunit I (COX1) and genomic data involving thousands of genome‐wide restriction‐site‐associated DNA markers (RAD‐seq). In the mitochondrial COX1 analyses, we detected one relatively common haplotype in commercial bumblebees, also present in wild samples collected nearby the green ‐houses where the commercial hives are used. In the RAD‐seq analysis, we found a clear genetic differentiation between native and commercial lineages. Furthermore,we detected candidate hybrids in the wild, as well as putatively escaped commercialbumblebees, some of which being potentially fertile males. Although we cannot as ‐sess directly the fitness effects of introgressed alleles, there is a risk of maladaptive allele introgression to the local bumblebee subspecies, which can negatively impact autochthon populations. One immediate recommendation to farmers is for the proper disposal of hive boxes, after their use in greenhouses, so as to minimize the risk of escapees contaminating native populations. On the other hand, the feasibilityof using local subspecies B. t. lusitanicus, preferably with local production, should be evaluated.
- Long-term survey of Eimeria spp. prevalence and faecal shedding in a traditional Portuguese free-range broiler farmPublication . Lozano, João; Palomero Salinero, Antonio; Anaya, Adriana; Lux Hoppe, Estevam G.; Gomes, Lídia; Oliveira, Manuela; Paz-Silva, Adolfo; Rebelo, Maria Teresa; Madeira de Carvalho, LuísIn free-range broiler production, animals are highly exposed to gastrointestinal parasitism, namely by coccidia, due to their long contact with the outdoor environment. Also, the prevalence of gastrointestinal parasites in extensive poultry production, is frequently influenced by biotic and abiotic factors. The current national pioneer long-term survey aimed to assess the prevalence and faecal shedding of Eimeria spp. oocysts in a traditional Portuguese free-range broiler farm, on different production conditions. Between July 2018 and March 2019, a total of 350 faecal samples were collected from different groups of free-range broilers at the fattening phase, in a poultry farm located in North-western Lisbon district, Portugal. Quantitative and qualitative coprological techniques were performed, aiming to quantify the Eimeria spp. prevalence and faecal shedding level. Coccidia prevalence was higher in Summer and Autumn groups (72% and 80%, respectively), although faecal shedding levels were higher in the Autumn and Winter groups (1191 and 1562 Oocysts Per Gram, OPG). Animals showed clinical signs of coccidiosis during the survey, especially in Autumn’s 1st sampling, in which 42% of the faecal samples had blood. The lack of sanitary depopulations, length of the fattening phase (1 month), short pre-patent period of coccidia, exposure to different environmental conditions and irregular drug treatments with amprolium, were key factors responsible for the different parasitic scenarios observed during this survey.
- Louse flies in Azorean and mainland populations of four Passeriformes species_a new perspective to parasite Island syndromesPublication . Tomás, André; Pereira da Fonseca, Isabel; Valkenburg, Thijs; Rebelo, Maria TeresaHippoboscid flies, also known as louse flies, are obligate blood-feeders ectoparasites of birds and mammals. By studying louse fly parasites of four Passeriformes species, Eurasian blackbird (Turdus merula), Eurasian blackcap (Sylvia atricapilla), common chaffinch (Fringilla coelebs) and European robin (Erithacus rubecula), with dissimilar time of colonization of Azores islands, we tested whether: (i) island host populations have lower parasite richness than the mainland one; (ii) island host populations undergo higher parasite prevalence, mean intensities and mean abundance than the mainland one; (iii) island parasite diversity are composed exclusively by specific parasites and (iv) parasite richness is positively correlated with the island area and proximity to the continent. For these purposes, 775 birds were sampled for presence of louse flies, by modified fumigation chamber method, from Azores Islands (S˜ao Miguel, Terceira and Flores) and Portugal mainland. Insular and mainland parasite assemblages were statistically compared. We record for the first time to Azores, Ornithomya fringillina and Icosta minor from Portugal mainland. Louse flies had highest prevalence and abundance from Azores Islands compared to those observed in mainland birds, especially blackbirds. The insular parasite diversity of Azores blackbirds, blackcaps and chaffinches was richer than the one observed in mainland population. None of the hippoboscid flies observed on the islands and mainland were host-specific. Thus, our findings provide an upgrade of parasite island syndromes knowledge, in the context of the ectoparasites, namely to the ippoboscid flies case.
- PCR-based detection of prey DNA in the gut contents of the tiger-fly, Coenosia attenuata (Diptera: Muscidae), a biological control agent in Mediterranean greenhousesPublication . G. Seabra, Sofia; Martins, Joana; Sequeira Brás, Patrícia; Tavares, Ana M.; Freitas, Inês; Barata, António; Rebelo, Maria Teresa; Mateus, Célia; Paulo, Octávio S.; Figueiredo, ElisabeteThe tiger-fl y Coenosia attenuata Stein (Diptera: Muscidae: Coenosiini) is a generalist predator that preys on several pests of greenhouse crops and is considered a biological control agent in the Mediterranean region. Previous behavioural observations identified its preferred prey, but a more in-depth evaluation will benefit from using Polymerase Chain Reaction amplification of prey DNA remains in the gut of this predator. To evaluate the rate of decay and suitability of this method for use in the field assessments, we carried out a laboratory feeding calibration experiment on 355 females of C. attenuata, which were killed at different intervals of time after ingestion (10 time points from 0 to 48 h). The prey species tested were: Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae: Trialeurodini), Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), Diglyphus isaea (Walker) (Hymenoptera: Eulophidae: Cirrospilini), Bradysia impatiens (Johannsen) (Diptera: Sciaridae) and Drosophila mercatorum Patterson & Wheeler (Diptera: Drosophilidae: Drosophilini). Based on a probit model, amplifi cation success of prey DNA declined exponentially with increasing time after ingestion. The half-time molecular detection differed between species, ranging from an average of 5 h for T. vaporariorum and D. isaea, 6 h for B. impatiens, 15 h for L. huidobrensis to more than 40 h for D. mercatorum. This study confi rmed the feasibility of using DNA based detection to identify prey species in the gut contents of C. attenuata and provided calibration curves for a better understanding of predation activity in this agroecosystem.