Bioactivity of aqueous extracts of Clibadium sylvestre (Aubl.) Baill. and Derris amazonica Killip on the aphid Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae)

Estudos com inseticidas botânicos vêm ganhando espaço como alternativa no Manejo Integrado de Pragas. Conduziu-se este trabalho com o objetivo de avaliar o efeito de extratos aquosos de folhas e frutos da espécie Clibadium sylvestre, e folhas e raízes da espécie Derris amazonica nas concentrações 0, 1, 2, 4 e 8%, no controle do pulgão Myzus persicae (Hemiptera: Aphididae). Foram conduzidos quatro ensaios, dois testes de preferência sem chance de escolha e dois testes de preferência com chance de escolha, totalizando nove tratamentos com cinco repetições. Foi realizada a triagem fitoquímica das folhas e dos frutos da espécie C. sylvestre e das folhas e das raízes de D. amazonica. As avaliações de mortalidade, número de ninfas e índice de deterrência dos insetos, foram realizadas 24, 48 e 72 horas após a aplicação dos extratos. Os extratos aquosos do fruto do C. sylvestre nas concentrações testadas apresentaram maior mortalidade frente à testemunha, na análise do número de ninfas, o extrato aquoso do fruto do C. sylvestre a 8% apresentou maior eficiência que os demais tratamentos. O extrato da folha de D. amazonica na concentração 1% apresentou maior mortalidade e menor número de ninfas que os demais tratamentos. Os extratos da raiz de D. amazonica aumentaram a mortalidade em todas as concentrações testadas e a concentração 8% da raiz de D. amazonica, apresentou menor número de ninfas. Todos os tratamentos testados apresentaram efeito deterrente. O período de 72 horas foi o que apresentou maior efeito dos extratos, das duas espécies estudadas sobre os insetos.

Feeding ecology of immature Lithodoras dorsalis (Valenciennes, 1840) (Siluriformes: Doradidae) in a tidal environment, estuary of the rio Amazonas

O estudo da ecologia alimentar de peixes é uma abordagem consistente na avaliação dos processos interativos dentro das comunidades. Dessa forma, este trabalho teve como objetivo investigar a ecologia alimentar do bacu-pedra Lithodoras dorsalis em furos próximos no delta do estuário Amazônico (Brasil), uma área sobre influência de macro-marés, em diferentes períodos pluviométricos. Durante 12 meses de coletas (julho de 2010 a junho de 2011), foram coligidos 371 espécimes jovens, sendo que a dieta da espécie foi composta por 28 itens alimentares analisados pelos seguintes índices: Índice de Repleção Estomacal, Índice de Importância Alimentar e Amplitude de Nicho. Lithodoras dorsalis quando jovem foi classificada como herbívora com tendência à frugivoria, devido aos altos valores de importância de frutos e sementes em sua dieta. A intensidade de obtenção de alimento por L. dorsalis diferiu entre os meses de coleta, onde o final do período de transição chuva-estiagem e o início da estiagem foram os períodos de menor e maior atividade alimentar, respectivamente. Também houve diferença na importância alimentar dos itens entre os períodos pluviométricos. Estes resultados fornecem informações importantes sobre a ecologia alimentar de doradídeos na Amazônia. Além disso, percebeu-se o alto consumo de material alóctone pelo bacu-pedra, sendo estes itens alimentares provenientes da floresta ripária, o que reforça a importância deste ambiente para a conservação da ictiofauna neotropical.

A mathematical approach to simulate spatio-temporal patterns of an insect-pest, the corn rootworm Diabrotica speciosa (Coleoptera: Chrysomelidae) in intercropping systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Trichomes related to an unusual method of water retention and protection of the stem apex in an arid zone perennial species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seedling fate across different habitats: the effects of herbivory and soil fertility

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Natural enemies depend on remnant habitat size in agricultural landscapes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bioactivity of pelargonium graveolens essential oil and related monoterpenoids against sweet potato whitefly, bemisia tabaci biotype B

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An Investigation of Wild Bee Diversity and Abundance in Plots Managed by The Nature Conservancy in South-Central Nebraska and of Beneficial Arthropods Associated with Native Nebraska Flora

Insect pollination is an essential ecosystem service, and bees are the principal pollinators of wild and cultivated plants. Habitat management and enhancement are a proven way to encourage wild bee populations, providing them with food and nesting resources. I examined bee diversity and abundance in plots managed by The Nature Conservancy near Wood River, NE. The plots were seeded with 2 seed mixes at 2 seeding rates: high diversity mix at the recommended rate, high diversity mix double the recommended rate, Natural Resources Conservation Service (NRCS) conservation planting (CP) 25 mix at one-half the recommended rate, and NRCS CP25 mix at the recommended rate. I measured wild bee abundance and diversity, and established a database of wild bees associated with the plots. I also compared genus richness and abundance among the plots using and aerial net and blue vane traps to collect bees. Significant differences were not observed in genus richness and diversity among the plots; however, plot size and the ability of blue vane traps to draw bees from a long distance may have influenced my results. In 2008, 15 genera and 95 individual bees were collected using an aerial net and in 2009, 32 genera and 6,103 individual bees were collected using blue vane traps. I also studied the beneficial insects associated with native Nebraska flora. Seventeen species of native, perennial flora were established in 3 separate plots located in eastern Nebraska. I transplanted four plants of each species in randomized 0.61 m x 0.61 m squares of a 3.05 m x 9.14 m plot. Arthropods were sampled using a modified leaf blower/vacuum. Insects and other arthropods were identified to family and organized into groups of predators, parasites, pollinators, herbivores, and miscellaneous. Associations between plant species and families of beneficial arthropods (predators, parasites, and pollinators) were made. Pycnanthemum flexuosum Walter attracted significantly more beneficial arthropod families than 7 other species of plants tested. Dalea purpurea Vent and Liatris punctata Hook also attracted significantly fewer beneficial arthropod families than 4 other species of plants tested. In total, 31 predator, 11 parasitic, 4 pollinator, 31 herbivore, and 10 miscellaneous families of arthropods were recorded.

Contributions of demography and dispersal parameters to the spatial spread of a stage-structured insect invasion

Stage-structured models that integrate demography and dispersal can be used to identify points in the life cycle with large effects on rates of population spatial spread, information that is vital in the development of containment strategies for invasive species. Current challenges in the application of these tools include: (1) accounting for large uncertainty in model parameters, which may violate assumptions of ‘‘local’’ perturbation metrics such as sensitivities and elasticities, and (2) forecasting not only asymptotic rates of spatial spread, as is usually done, but also transient spatial dynamics in the early stages of invasion. We developed an invasion model for the Diaprepes root weevil (DRW; Diaprepes abbreviatus [Coleoptera: Curculionidae]), a generalist herbivore that has invaded citrus-growing regions of the United States. We synthesized data on DRW demography and dispersal and generated predictions for asymptotic and transient peak invasion speeds, accounting for parameter uncertainty. We quantified the contributions of each parameter toward invasion speed using a ‘‘global’’ perturbation analysis, and we contrasted parameter contributions during the transient and asymptotic phases. We found that the asymptotic invasion speed was 0.02–0.028 km/week, although the transient peak invasion speed (0.03– 0.045 km/week) was significantly greater. Both asymptotic and transient invasions speeds were most responsive to weevil dispersal distances. However, demographic parameters that had large effects on asymptotic speed (e.g., survival of early-instar larvae) had little effect on transient speed. Comparison of the global analysis with lower-level elasticities indicated that local perturbation analysis would have generated unreliable predictions for the responsiveness of invasion speed to underlying parameters. Observed range expansion in southern Florida (1992–2006) was significantly lower than the invasion speed predicted by the model. Possible causes of this mismatch include overestimation of dispersal distances, demographic rates, and spatiotemporal variation in parameter values. This study demonstrates that, when parameter uncertainty is large, as is often the case, global perturbation analyses are needed to identify which points in the life cycle should be targets of management. Our results also suggest that effective strategies for reducing spread during the asymptotic phase may have little effect during the transient phase. Includes Appendix.

Adopting an integrated, flexible approach to reducing the birdstrike risk from Canada geese

Canada Geese overflying the runways at London’s Heathrow Airport have been struck on eleven occasions by aircraft during the last ten years. Four of these occurred during the pre-breeding season and seven during the post moult period. A monitoring study was initiated in 1999 to evaluate the movements of geese around the airport and determine appropriate mitigation strategies to reduce the risk of birdstrike. Moult sites within 13km of the airport were identified. 4,900 moulting geese were caught and fitted with colour rings and radio-transmitters between 1999 and 2004. 2,500 visits were made to over 300 sites resulting in over 10,000 sightings of known individuals. Birds that crossed the airport approaches whilst moving between roost sites and feeding areas in newly harvested cereal crops were identified. Throughout the monitoring period efforts were made to control the risk, but by 2003 it was estimated that 10,000 bird transits of the approaches involving almost 700 individuals occurred during a 50 day period. The knowledge of the movements of ringed and tagged birds was used to inform a revised habitat management, daily roost dispersal and on-airfield bird deterrence programme in 2004. By adopting a flexible approach to management, an estimated 70% reduction in bird transits was achieved. This paper discusses the techniques used to achieve this reduction.

Estudo histológico e comparativo das papilas linguais dos cervídeos Mazama americana e Mazama gouzoubira por microscopia de luz e eletrônica de varredura

O tipo de alimentação depende do ambiente em que o animal se encontra, sendo este um fator responsável pela alteração da morfologia, como a estratificação e o nível de queratinização da língua, e a funcionalidade da mesma. Dentre as estruturas morfológicas funcionais da língua, as papilas vêm merecendo destaque devido a sua estreita relação com a dieta. Foram utilizadas duas espécies de cervídeos: cinco Mazama gouazoubira e duas Mazama americana, dividindo-se a língua em três partes: ápice, corpo e raiz. Analisou comparativamente a língua de duas espécies por meio de microscopia de luz e eletrônica de varredura. As papilas filiforme, fungiforme e valada apresentaram na língua das duas espécies estudadas, e com a mesma distribuição, mudando apenas a quantidade e formato de papilas filiformes no ápice lingual e a quantidade e disposição das papilas valadas na raiz da língua, fator este que pode ser ligado à dieta dos animais. . Além disto, sua distribuição é semelhante à de outras espécies de herbívoros.

CLEANING ASSOCIATIONS BETWEEN BIRDS AND HERBIVOROUS MAMMALS IN BRAZIL: STRUCTURE AND COMPLEXITY

Birds that remove ectoparasites and other food material from their hosts are iconic illustrations of mutualistic-commensalistic cleaning associations. To assess the complex pattern of food resource use embedded in cleaning interactions of an assemblage of birds and their herbivorous mammal hosts in open habitats in Brazil, we used a network approach that characterized their patterns of association. Cleaning interactions showed a distinctly nested pattern, related to the number of interactions of cleaners and hosts and to the range of food types that each host species provided. Hosts that provided a wide range of food types (flies, ticks, tissue and blood, and organic debris) were attended by more species of cleaners and formed the core of the web. On the other hand, core cleaner species did not exploit the full range of available food resources, but used a variety of host species to exploit these resources instead. The structure that we found indicates that cleaners rely on cleaning interactions to obtain food types that would not be available otherwise (e.g., blood-engorged ticks or horseflies, wounded tissue). Additionally, a nested organization for the cleaner bird mammalian herbivore association means that both generalist and selective species take part in the interactions and that partners of selective species form an ordered subset of the partners of generalist species. The availability of predictable protein-rich food sources for birds provided by cleaning interactions may lead to an evolutionary pathway favoring their increased use by birds that forage opportunistically. Received 30 June 2011, accepted 10 November 2011.

Marine Seaweed Invasions : the Ecology of Introduced Fucus evanescens

Biological invasions are an important issue of global change and an increased understanding of invasion processes is of crucial importance for both conservation managers and international trade. In this thesis, I have studied the invasion of the brown seaweed Fucus evanescens, to investigate the fate and effect of a perennial, habitat-forming seaweed introduced to a coastal ecosystem. A long-term study of the spread of F. evanescens in Öresund (southern Sweden) showed that the species was able to expand its range quickly during the first 20 years after the introduction, but that the expansion has been slow during the subsequent 30 years. Both in Öresund and in Skagerrak, the species is largely restricted to sites where native fucoids are scarce. Laboratory experiments showed that the restricted spread of F. evanescens cannot be explained by the investigated abiotic factors (wave exposure and salinity), although salinity restricts the species from spreading into the Baltic Sea. Neither did I find evidence for that herbivores or epibiota provide biotic resistance to the invader. On the contrary, F. evanescens was less consumed by native herbivores, both compared to the native fucoids and to F. evanescens populations in its native range, and little overgrown by epiphytes. Instead, the restricted spread may be due to competition from native seaweeds, probably by pre-occupation of space, and the establishment has probably been facilitated by disturbance. The studies provided little support for a general enemy release in introduced seaweeds. The low herbivore consumption of F. evanescens in Sweden could not be explained by release from specialist herbivores. Instead, high levels of chemical anti-herbivore defence metabolites (phlorotannins) could explain the pattern of herbivore preference for different fucoids. Likewise, the low epibiotic colonisation of F. evanescens plants could be explained by high resistance to epibiotic survival. This shows that colonisation of invading seaweeds by native herbivores and epibionts depends on properties of the invading species. The large differences between fucoid species in their quality as food and habitat for epibionts and herbivores imply that invasions of such habitat-forming species may have a considerable effect on a number of other species in shallow coastal areas. However, since F. evanescens did not exclude other fucoids in its new range, its effect on the recipient biota is probably small.

Herbivory intensity over two coexisting macrophytes on soft bottoms of Gran Canaria Island

Máster en Oceanografía

Aspetti processuali del Regolamento n. 1/2003/Ce

The recent reform in European antitrust enforcement is embodied in Regolation n. 1/2003/ Ce and related Communications. Since 2004 when it came into force, some crytical assessments can already be made. The work starts from some technical analysis of the reform, under a procedural perspective, to assess the proceedings’ real impact on parties’ rights and to criticize its limits. Decentralisation has brought about more complicacies, since community procedural systems are not harmonized, neither in their administrative rules, nor in their civil proceedings, which are all involved in the European antitrust network. Therefore, antitrust proceedings end un as being more jurisdictional in their effects than in their guarentees, which is a flaw to be mended by legislators. National laws shoud be harmonized, community law should be clarified and the system should turn more honestly towards a rationalized jurisdiction-cented mechanism. Otherwise, parties defense rights and the overall efficiency are put into doubt. Italy is a good exemple of how many colmlicacies can outburst from national procedures and national decentralised application. An uncertain pattern of judicial control, together with unclear relationships among the institutions to cooperate in the antitrust network can produce more problems than they aim to solve. As to the private enforcement, Regulation n.1 does not even attempt to give precise regulation to this underdeveloped sector. A continual comparison with U.S. system has brought the Commission to become aware both of the risks and of the advanteges of an increased civil antitrust litigation in fronto of national judges. In order to substain a larger development of this parallel and, presently, difficult way of judicial compensation, it is presently ongoing a consultation among states to find suitable incentives to make private enforcement more appealing and effective. The solution to this lack of private litigation is not to be sought in Regulation n. 1 which calls into action national legislators and proceedures to implement further improvements. As a conclusion, Regulation n. 1 is the outpost of an ambitious community design to create an efficient control mechanism over antitrust violations. It focuses on Commission proceedings, powers and sanctions in order to establish deterrence, then it highlights civil litigation perspectives and it involves directly states into antitrust application. It seems that more could be done to technically shape administrative proceedings in a more jurisdictionally oriented form, then to clarify respective roles and coordination mecanisms in order to prevent difficulties easy to forsee. Some of jurisprudential suggestions have been accepted, but much more is left to be done in the future to improve european antitrust enforcement system.