960 resultados para Predatory mite
Resumo:
Individuals need to adapt to their local environment in order to survive. When selection pressures differ in local populations, polymorphism can evolve. Colour polymorphism is one of the most obvious polymorphisms since it is readily observable. Different sources of colouration exist, but melanin-based colouration is one of the most common in birds. The melanocortin system produces this colouration and because the melanocortin system has pleiotropic effects on behavioural and physiological traits, it is a good candidate to be an underlying mechanism to explain the maintenance of colour polymorphism. In this thesis I studied three different raptors which all display melanin-based colouration; barn owls (Tyto alba), tawny owls (Strix aluco) and Eurasian kestrels (Falco tinnunculus). The main question was if there was a relationship between melanin-based colouration and individual behavioural differences. The underlying hypothesis is that colour could be a signal of certain adaptive traits. Our goal was to find evolutionary explanations for the persistence of colour polymorphism. I found that nestling kestrels and barn owls differ in anti-predatory behaviour, with respect to their melanic colouration (chapters 1 and 2). Darker individuals show less reaction to human handling, but in kestrels aggression and colouration are related in opposite ways than in barn owls. More reddish barn owls travel greater distances in natal dispersal and this behaviour is repeatable between parents and same sex offspring (chapter 3). Dark reddish tawny owls defend their nests more intensely against intruders and appear to suffer less from nest predation (chapter 4). Finally I show that polymorphism in the Melanocortin 1 receptor gene (MC1R), which is strongly correlated with reddish colouration in the barn owl, is related to natal dispersal distance, providing a first indication for a genetic basis of the relation between this behaviour and colouration (chapter 5). My results demonstrate a clear link between melanin-based colouration and animal personality traits. I demonstrated this relation in three different species, which shows there is most likely a general underlying mechanism responsible. Different predation pressures might have shaped the reactions to predation, but also differences in sex-related colouration. Male-like and female-like colouration might signal more or less aggressive behaviour. Fluctuating environmental conditions might cause different individual strategies to produce equal reproductive success. The melanocortin system with its pleiotropic effects might be an underlying mechanism, as suggested by the results from the genetic polymorphism, the similar results found in these three species and by the similar relations reported in other species. This thesis demonstrates that colouration and individual differences are correlated and it provides the first glimpse of an underlying system. We can now conduct a more directed search for underlying mechanisms and evolutionary explanations with the use of quantitative genetic methods.
Resumo:
OBJECTIVE We aimed to analyze health-related quality of life (HRQOL) in adults with newly diagnosed respiratory allergy according to the sensitization profile for relevant aeroallergens in their usual area of residence. METHODS We performed a cross-sectional, epidemiological, observational, descriptive, multicenter study in allergy clinics in Spain. The sample comprised adults diagnosed with rhinitis, asthma, or both caused by significant allergens in their residential area (olive and/or grass pollen or house dust mite). Allergic rhinitis was classified according to the Allergic Rhinitis and its Impact on Asthma guidelines; asthma was classified according to the Guía Españiola para el Manejo del Asma (Spanish Guideline on the Management of Asthma). HRQOL was studied according to the ESPRINT-15 questionnaire and Mini Asthma Quality of Life Questionnaire. Control of asthma was measured using the Asthma Control Questionnaire 5. RESULTS We studied 1437 patients. Rhinitis was the most common respiratory disease. The HRQOL of rhinitis patients was lower in those sensitized to olive pollen only and in those with combined sensitization to olive and grass pollens. HRQOL associated with rhinitis was worse in patients diagnosed with both rhinitis and asthma than in patients diagnosed with rhinitis only. Asthma patients sensitized to olive pollen or olive and grass pollens had worse HRQOL. CONCLUSIONS In our study population, the HRQOL of patients with respiratory allergies varied with the allergen responsible for symptoms. In patients with rhinitis, the presence of asthma significantly worsened rhinitis-associated HRQOL.
Resumo:
Interspecific mutualisms are an essential feature of life on earth, yet we know little about their evolution and stability. In many mutualisms several species are available as partners, raising questions about the similarity in function and behavioural repertoire depending on the partner species. Furthermore, variation between species in the quantity and quality of interactions resulting in variation in payoffs may allow us to infer the potential evolutionary origin of a multispecies mutualism complex. We addressed these issues in the marine cleaning mutualism, in which so-called 'cleaners' remove ectoparasites from so-called 'client' reef fish. We measured several parameters concerning the quantity and quality of cleaning interactions in six sympatric cleaner wrasse species. We found significant variation between cleaner species with respect to client diversity, the number of interactions with predatory clients, the duration of interactions, the frequency of client jolts as a correlate of 'cheating' by cleaners, and behaviours used for manipulation of client decisions. Exploratory correlations between cleaner species' dependency and our variables of interest suggest that cleaning originated as a conflict-free by-product mutualism and evolved towards more sophisticated behaviours, including strategic behaviours for interactions with predators, cheating and manipulation specifically adapted to the client type.
Resumo:
Presentació d’un dossier que tracta l’acostament crític a la figura del bisbe Narcís i als prodigis que li han estat atribuïts, així com a la producció historiogràfica i artística que ha generat el mite
Resumo:
To investigate the potential for host-parasite coadaptation between bats and their wing mites, we developed microsatellite loci for two species of Spinturnix mites. For Spinturnix myoti, parasite of Myotis myotis, we were able to develop nine polymorphic loci and screened them in 100 mites from five bat colonies. For S. bechsteini, parasite of M. bechsteinii, we developed five polymorphic loci, which were also screened in 100 mites from five bat colonies. In both species, all markers were highly polymorphic (22-46 and 6-23 alleles per locus respectively). The majority of markers for both species exhibited departure from Hardy-Weinberg proportions (8 of 9 and 3 of 5, respectively). One marker pair in S. myoti showed evidence for linkage disequilibrium. As the observed departures from Hardy-Weinberg proportions are most likely a consequence of the biology of the mites, the described microsatellite loci should be useful in studying population genetics and host-parasite dynamics of Spinturnix myoti and Spinturnix bechsteini in relation to their bat hosts.
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Aquest treball se situa en el marc de l'estudi de les mirades en el cinema clàssic de Hollywood. S'interroga, en concret, sobre una mirada: la que alguns personatgesdirigeixen a la seva imatge especular. A la llum del mite de Narcís, es proposa escatirquin és el desig que va unit a aquesta mirada i quins efectes produeix sobre aquells que hi recorren, sobretot pel que fa a la fonamentació de la seva subjectivitat.Després de la identificació i l'examen de les figures cinematogràfiques que mostrenpunts de contacte amb la figura de Narcís, s'ha procedit a una exploració de les imatgesque les mostren mirant-se al mirall, per tal de precisar els trets que defineixen la sevamirada. Finalment, s'han resseguit certes variacions i prolongacions del mite de Narcís, presents també al cinema clàssic, per tal de veure l'evolució que hi sofreixen tant la pròpia mirada com la relació dels personatges amb la seva imatge. Aquest recorregut ha permès d'extreure algunes conclusions sobre la qüestió principal que ens havíem plantejat
Resumo:
Sap la gent quin és el model de recollida selectiva porta a porta? Ajuda aquest sistema a la preservació del medi ambient o es tracta simplement d’un mite? Això és el que ens vam preguntar nosaltres a l’inici del treball. Aquest model s’aplica des del mes de novembre del 2008 a Palau-solità i Plegamans, un municipi del Vallès Occidental. A partir de l’estudi d’aquest cas pràctic hem volgut analitzar la viabilitat d’aquest sistema i la seva acceptació social. Comprovarem que aquest sistema és deficitari i que els impostos juguen un paper molt important en el finançament del sistema actual.Un altre objectiu és comparar el sistema porta a porta que hi ha actualment amb el que es va proposar en l’anterior legislatura, basat en la divisió del poble en dues zones amb models de recollida diferents. Concretament, ens interessa saber si va ser una bona idea canviar de sistema i, tal com veurem més endavant, la resposta és afirmativa.També volem saber si aquest model es podria aplicar a altres municipis amb densitat i poblacions diferents. A través d’aquest treball, veurem que la densitat de la població és un dels factors més importants, malgrat que influeixen altres elements (per exemple, l’acceptació social).
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Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say). The investigation was performed in climatic chamber at 25 ±1 ºC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller), adults of Caliothrips phaseoli (Hood) and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days) compared to that of adults that preyed on nymphs of A. gossypii (11.44 days), and four times larger when the prey were adults of C. phaseoli (13.58 days). The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days) and a longer oviposition period (44.4 days) when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female) when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female) or A. gossypii (22.50 eggs laid / female). However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage) than that of thrips (74.10 thrips / nymphal stage) or eggs of A. kuehniella (37.03 eggs /nymphal stage) for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of prey best suited for rearing this predator insect under laboratory conditions. Also fecundity was better with this prey even though the predator consumed during its nymphal stage a lesser quantity of eggs compared to the other prey.
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The genus Orius Wolff, 1811 comprises predatory species, with approximately 70 known species. Informations about the genus in Brazil are scarce. Therefore, the aim of this investigation was to identify Orius species present in four localities in the southeastern Brazil. Samples were taken from several plants, and the material screened in laboratory. The genitalia of both sexes were studied and illustrated. Two species were identified, Orius insidiosus (Say, 1832) and Orius thyestes Herring, 1966. O. insidiosus, the most common species, was collected in all of the localities sampled [Lavras (MG), Holambra, Pindorama and Campinas (SP)]. O. thyestes, registered for the first time in Brazil, occurred only in Lavras (MG) and Pindorama (SP). Some morphologic aspects of these two species are also presented.
Resumo:
Calacarus heveae Feres, 1992 is an Eriophyidae mite described from rubber tree (Hevea brasiliensis Muell. Arg.) in the northwest region of the State of São Paulo. This mite prefers the adaxial face of the folioles and it can reduce the brightness of the leaves, turning them progressively yellow and brownish, and consequently premature fall. The aim of this work was to study the biology of C. heveae in laboratory, on detached rubber tree folioles. The study was conducted at 28±1 ºC in the photophase (12h), 25±1 ºC in the dark phase (12h), and 90±5% relative humidity. The study was initiated with a total of 59 eggs. The average duration of egg, larva and nymph stages was 5.8, 2.0 and 1.4 days, respectively. The period from egg to adult lasted 9.3 days, and the average periods of pre-oviposition, oviposition and post-oviposition, 1.8, 6.1 and 1.2 days, respectively. The average longevity of the adult male was ca. 4.0 days, while the longevity adult female was about 8.4 days. The average daily oviposition rate was 2.3 egg per female while the average fecundity was 16.2 eggs per female.
Resumo:
1. Sex differences in levels of parasite infection are a common rule in a wide range of mammals, with males usually more susceptible than females. Sex-specific exposure to parasites, e.g. mediated through distinct modes of social aggregation between and within genders, as well as negative relationships between androgen levels and immune defences are thought to play a major role in this pattern. 2. Reproductive female bats live in close association within clusters at maternity roosts, whereas nonbreeding females and males generally occupy solitary roosts. Bats represent therefore an ideal model to study the consequences of sex-specific social and spatial aggregation on parasites' infection strategies. 3. We first compared prevalence and parasite intensities in a host-parasite system comprising closely related species of ectoparasitic mites (Spinturnix spp.) and their hosts, five European bat species. We then compared the level of parasitism between juvenile males and females in mixed colonies of greater and lesser mouse-eared bats Myotis myotis and M. blythii. Prevalence was higher in adult females than in adult males stemming from colonial aggregations in all five studied species. Parasite intensity was significantly higher in females in three of the five species studied. No difference in prevalence and mite numbers was found between male and female juveniles in colonial roosts. 4. To assess whether observed sex-biased parasitism results from differences in host exposure only, or, alternatively, from an active, selected choice made by the parasite, we performed lab experiments on short-term preferences and long-term survival of parasites on male and female Myotis daubentoni. When confronted with adult males and females, parasites preferentially selected female hosts, whereas no choice differences were observed between adult females and subadult males. Finally, we found significantly higher parasite survival on adult females compared with adult males. 5. Our study shows that social and spatial aggregation favours sex-biased parasitism that could be a mere consequence of an active and adaptive parasite choice for the more profitable host.
Resumo:
Life cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets from three rubber tree clones. The biological cycle of Tenuipalpus heveae Baker, 1945 (Tenuipalpidae), a potential rubber tree pest mite, was studied by the observation of individuals reared on leaflets of the clones GT 1, PB 235 and RRIM 600, in controlled environmental conditions. Three daily observations were done of 60 eggs on leaflets from each clone in order to verify the development of immature stages and the female oviposition. The fertility life table was constructed based in the collected data. Mites reared on PB 235 had faster rate of development, requiring less time in days, to double its population in number (TD), and had the highest values for egg production, female longevity, net reproductive rate (Ro), intrinsic rate of natural increase (r m) and finite rate of increase (λ). Lower reproductive values and the longest time necessary to reach adult stage were recorded for the mites on GT 1. In all studied clones, the deutonymphal phase had the highest viability, while the larval phase had the lowest, highlighted by the survivorship curve that indicated high mortality during this life stage. The clone PB 235 allowed the most suitable conditions for the development of T. heveae, followed by RRIM 600, while GT 1 was the less suitable substratum to rear this mite species.
Resumo:
Mites associated to Xylopia aromatica (Lam.) Mart. (Annonaceae) in urban and rural fragments of semidecidual forest. Native plants can shelter a great diversity of mites. Notwithstanding, the conservation of the forest fragments where the plants are located can influence the structure of the mites community. Generally, in homogenous environments the diversity is lower due to the dominance of one or a few species. In this work, we studied the mite community on Xylopia aromatica (Lam.) Mart. (Annonaceae) in two fragments of semidecidual forest: one on rural and other on urban area. Seven individuals of X. aromatica were monthly sampled from April 2007 to March 2008, in each of these fragments. Descriptive indexes of diversity, dominance and evenness were applied to verify the ecological patterns of the mite community, besides the Student's t-test to compare the abundance between the fragments. We collected 27,365 mites of 37 species belonging to 11 families. Calacarus sp. (Eriophyidae) was the most abundant species, representing 73% of the total sampled. The abundance was greater in the urban fragment (67.7%), with the diversity index reaching only 25% of the theoretical maximum expected. Probably, these values might have been influenced by the location of this fragment in the urban area, being more homogeneous and submitted directly to the presence of atmospheric pollution. In this manner, X. aromatica is able to shelter a higher diversity of mites when inserted in preserved ecosystems, since the highest diversity of available resources allows the establishment of richer and most diverse mite community.
Resumo:
Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål) (Hemiptera, Pentatomidae)? The stink bug Supputius cincticeps (Stål) (Hemiptera, Pentatomidae) is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L.) (Coleoptera, Tenebrionidae), Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae), and Thyrinteina arnobia (Stoll) (Lepidoptera, Geometridae) were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey) depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.
Resumo:
Interaction between Musca domestica L. and its predator Muscina stabulans (Fallén) (Diptera, Muscidae): Effects of prey density and food source abundance. The objective of this work was to evaluate the influence of prey density and food source abundance on the predatory behavior of Muscina stabulans over M. domestica. Three predator/prey proportions were evaluated (1:1, 1:3 and 1:6), using 100 third instar predator larvae against second instar prey larvae. Each proportion was maintained using three different levels of food substrate (25, 50 and 100 g). The experiments were carried out in triplicate in BOD incubators (25ºC, UR 70% ± 10% and 12 h photoperiod). The mortality of the M. domestica larvae was 100% under all conditions, except in the 1:6 predator/prey proportion, at the 50g and 100g food substrate levels, where it was 99.99% and 99.22%, respectively. There was a significant increase in the development period of M. stabulans in relation to the increase in prey density and decrease in quantity of food substrate. An increase in the proportion of individuals and a reduction in the amount of resource slowed down larval development. Muscina stabulans pupal weight was proportional to the increase in prey density and the amount of food substrate. The proportion or the density influenced the survival of M. stabulans, with no difference in relation to the amount of food source and consequently in the interaction of the factors. There was no difference between the 1:1 and 1:3 predator-prey densities, with both differing from the 1:6 density.