53 research outputs found
Seasonal fecundity and body size in Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae)
Metapopulation Dynamics on Ephemeral Patches
A challenge for conservation management is to understand how population and habitat dynamics interact to affect species persistence. In real landscapes, timing and duration of disturbances can vary, and species' responses to habitat changes will depend on how timing of dispersal and reproduction events relate to the landscape temporal structure. For instance, increasing disturbance frequency may promote extinction of species that are unable to appropriately time their reproduction in an ever-changing habitat and favor species that are able to track habitat changes. We developed a mathematical model to compare the effects of pulsed dispersal, initiated by shifts in habitat quality, with temporally continuous dispersal. We tested the effects of habitat (and population) turnover rates on metapopulation establishment, persistence, and long-term patch occupancy. Pulsed dispersal reduced patch occupancy and metapopulation longevity when habitat patches are relatively permanent. In such cases, demographic extinction was the primary form of local extinction. Conversely, when habitat patches are short-lived and new ones are frequently formed, pulsed dispersal promoted rapid colonization, increased occupancy, and prolonged metapopulation persistence. Our results show that species responsiveness to habitat disturbance is critical to metapopulation persistence, having profound implications for the species likely to persist in landscapes with altered disturbance regimes
Multi-state models for double transitions associated with parasitism in biological control
Competition between parasitoids can reduce the success of pest control in
biological programs using two species as bio-control agents or when multiple
species exploit the same host crop. Parasitoid foraging behavior and the
ability to identify already parasitized hosts affect the efficacy of parasitoid
species as bio-agents to regulate pest insects. We evaluated the behavioural
changes of parasitoids according to the quality of hosts ({\it i.e.},
previously parasitised or not), and the characterisation of these transitions
over time via multi-state models. We evaluated the effects of previous
parasitism of the brown stinkbug {\it Euschistus heros} eggs on the parasitism
rate of the species {\it Trissolcus basalis} and {\it Telenomus podisi}. We
successively modelled the choice of eggs (with three possibilities: non
parasitised eggs, eggs previously parasitised by {\it T. podisi}, and eggs
previously parasitised by {\it T. basalis}) and the conditional behaviour given
the choice (walking, drumming, ovipositing or marking the chosen egg). We
consider multi-state models in two successive stages to calculate double
transition probabilities, and the statistical methodology is based on the
maximum likelihood procedure. Using the Cox model and assuming a stationary
process, we verified that the treatment effect was significant for the choice,
indicating that the two parasitoid species have different choice patterns. For
the second stage, i.e. behaviour given the choice, the results also showed the
influence of the species on the conditional behaviour, especially for
previously parasitised eggs. Specifically, {\it T.podisi} avoids intraspecific
competition and makes decisions faster than {\it T. basalis}. In this work, we
emphasise the methodological contribution with multi-state models, especially
in the context of double transitions.Comment: 16 page
ATENÇÃO PRIMÁRIA À SAÚDE, DIAGNÓSTICO PRECOCE DAS DOENÇAS DERMATOLÓGICAS E SEU IMPACTO SOCIAL
Esse estudo objetivou levantar as doenças dermatológicas prevalentes na população atendida pela UBS Jardim Valença, direcionando uma revisão de literatura sobre o tema. Entre outubro e dezembro de 2017, todas as queixas dermatológicas apresentadas durante consulta na unidade de saúde foram registradas e analisadas por estatística descritiva. As mais frequentes afecções foram dermatofitoses, pediculose, dermatites atópica e de contato. De acordo com os dados encontrados, foi possível realizar revisão bibliográfica direcionada e entender o perfil epidemiológico das doenças dermatológicas na população estudada, contribuindo com a melhoria do cuidado e resolutividade da equipe de saúde da família. As doenças dermatológicas são prevalentes na população, e seu diagnóstico e tratamento precoces contribuem para diminuir seu impacto na vida dos pacientes e gastos para o sistema de saúde. A atenção primária à saúde é o ponto de acesso preferencial do sistema de saúde e, se apresenta resolutividade e qualificação, é capaz de resolver a maioria das queixas dermatológicas comumente apresentadas
Cross-crop effects on larval growth, survivorship and fecundity of Helicoverpa armigera
The cotton bollworm Helicoverpa armigera is a
destructive pest that affects a variety of crop plants.
Because of its polyphagous feeding habit, mobility as
adults, and high fecundity, the expanding infestations of H.
armigera in different crops have caused economic losses
and difficulties for pest population management. In Brazil,
a sequence of different crop systems in the same area and
crop rotation during the year can create a spatio-temporal
mosaic of crops where H. armigera can persist. However,
the consequences of the simultaneous and/or alternating
presence of host plants for H. armigera populations
through generations are unknown. In this study, we simulated, in the laboratory, hypothetical situations for the
availability of soybean and cotton crops in the landscape.
We evaluated the effects of: (1) the number of generations
during which a population feeds on a host-plant species; (2)
the succession of host-plant species on which populations
have fed for two generations; and (3) the parental host plant
on the fitness of H. armigera populations. Only the current
host plant on which larvae fed affected the performance of
the H. armigera populations. Decrease of mortality rates
during the immature period was slowed when the larvae
fed on soybean. The lowest value of reproductive potential
(R0) was found for individuals originating from mating
between females and males reared in cotton. Our results
indicated that pest-management and biological-control
plans for H. armigera should be developed on a regional
scale rather than for just a specific crop area
Composition of Anastrepha species (Diptera: Tephritidae) in habitats with different levels of anthropogenic activity
We collected Anastrepha species in three areas (urban, research station, agricultural) and compared communities by faunal indices (dominance, abundance, frequency, and constancy). Species diversity was estimated using the Q-statistic and by calculating Shannon, Margalef Pielou and Berger-Parker indices. Similarity among areas was based on Sørensen and Bray-Curtis coefficients. The urban and research station areas presented greater diversity and similarity of Anastrepha species. Species composition differed between areas, with predominance of A. fraterculus (Wiedemann, 1830) in the three areas. Distribution patterns did not differ after adjusting the geometric series. The agricultural area was the least diverse and more closely resembled the urban area in terms of abundance. The urban area and research station were the most diverse, and were similar in composition of Anastrepha species. Despite being subject to different levels of human disturbance, these results suggest that the abundance and distribution pattern of Anastrepha species are similar in all three areas
O uso da pesquisa-ação para a avaliação e o aprimoramento de práticas integradas para a vigilância da qualidade da água para consumo humano: potencialidades e desafios
Extratos de Piper marginatume Azadirachta indica no controle de Colletotrichum scovillei em pimentão
Dinâmica tritrófica experimental em populações de moscas varejeiras
Este estudo teve a finalidade de analisar empírica e teoricamente a dinâmica de sistemas bi e tritróficos constituídos por dípteros e parasitóides, sob condições experimentais. Para tanto, cinco capítulos foram organizados para a apresentação dos resultados: (1) Sobrevivência da fauna de parasitóides associada a moscas varejeiras em Botucatu, São Paulo, Brazil; (2) Implicações da escolha do hospedeiro para parasitóides generalistas; (3) 0 papel de parasitóides generalistas na regulação de hospedeiros: resposta funcional e numérica; (4) Relações tróficas e efeito cascata: proposta experimental com meta-análise e (5) Predação intraguilda governa persistência modulando canibalismo e parasitismo em interações tritróficas. Os dípteros hospedeiros foram as espécies da família Calliphoridae Cochiliomya macellaria, Chrysomya megacephala, Chrysomya putoria, Chrysomya albiceps e Lucilia sericata. Um levantamento faunístico foi realizado para se conhecer os parasitóides associados aos dípteros califorídeos da região de Botucatu. Foram encontradas nove espécies parasitóides durante dois anos de coleta. Dos parasitóides amostrados, quatro espécies foram selecionadas para investigar aspectos ecológicos da interação hospedeiro-parasitóide, tais como: escolha de hospedeiros, resposta funcional e numérica, relações tróficas e potencial dos parasitóides como agentes reguladores da população de hospedeiros. Uma análise da dinâmica tritrófica foi feita com auxílio de modelagem matemática adequada aos dados obtidos na experimentação. As relações entre predador e presa intraguilda, canibalismo do predador e ação do parasitóide sobre presa e predador intraguilda foram analisados sob a ótica empírica e teórica, valendo-se de experimentos laboratoriais e modelagem ecológica. Os resultados apresentados nos cinco capítulos mostram aspectos ecológicos...A survey of the parasitoid fauna associated with blowflies was carried out in one rural, one urban, and one wild area of the municipality of Botucatu, State of São Paulo, Brazil, over two years (2005-2007). For the survey, larvae and pupae of five blowfly species, Chrysomya albiceps, C. megacephala, C. putoria, Cochliomya macellaria, and Lucilia sericata were offered as hosts in traps. The following species of Chalcidoidea were found: Nasonia vitripennis, Pachycrepoideus vindemiae, Tachinaephagus zealandicus, Spalangia endius, Spalangia dozieri, two species of Tachinobia and Eurytoma sp. Also was found a species of Diapriidae (Proctotrupoidea). In general, parasitoid species were more abundant during winter and spring, periods with low temperature, humidity, and rainfall. The general parasitism frequency was influenced only by the humidity, i.e., when humidity was low, the parasitoid occurrence was high. Chrysomya albiceps, L. sericata, and C. putoria were the most parasitized species. The highest parasitoid occurrence was in the rural area, and the most abundant species were N. vitripennis, P. vindemiae, and T. zealandicusFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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