Embora a oscilação na pressão barométrica possa afetar o comportamento dos insetos, o seu efeito é ainda pouco explorado para a maioria das espécies. Neste contexto investigou-se em diferentes condições de pressão barométrica os comportamentos de alimentação e oviposição de Diabrotica speciosa (Germ.) (Coleoptera: Chrysomelidae) e Euschistus heros (F.) (Hemiptera: Pentatomidae), oviposição de Spodoptera frugiperda (Walker) (Lepidoptera: Noctuidae) e o parasitismo por Trissolcus basalis (Woll.) (Hymenoptera: Scelionidae), Habrobracon hebetor (Say) (Hymenoptera: Braconidae) e Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). Para isso, foram simuladas as atividades de comportamento mencionadas, dentro de uma câmara barométrica, em condições controladas de pressão baixa, estável e alta, mantendo as demais condições abióticas estáveis. Evidenciou-se que a pressão barométrica pode exercer uma influência em diversas atividades comportamentais nos insetos, mas que não necessariamente possa ser generalizada para todas as espécies e situações. O comportamento de alimentação foi afetado de modo diferenciado para insetos sugadores e mastigadores. Foi observada uma diminuição no número de bainhas alimentares de adultos do percevejo E. heros submetidos a condições de baixa pressão barométrica. Por outro lado, o consumo foliar de adultos de D. speciosa não foi afetado pela pressão. O comportamento de oviposição de E. heros, D. speciosa e S. frugiperda, não foi influenciado significativamente pela pressão barométrica. O parasitismo por T. basalis não foi influenciado pelas condições de pressão barométrica. Entretanto, em condição de baixa pressão barométrica, houve redução no parasitismo por H. hebetor e C. flavipes. / Although barometric pressure oscillation may affect insects\' behavior, that effect is not explored for most species. Weather changes can be associated to patterns of barometric pressure fluctuations. In this sense, we investigated feeding of Diabrotica speciosa (Germ.) (Coleoptera: Chrysomelidae) and Euschistus heros (F.) (Hemiptera: Pentatomidae); oviposition of Spodoptera frugiperda (Walker) (Lepidoptera: Noctuidae), Diabrotica speciosa and Euschistus heros; and parasitism by Trissolcus basalis (Woll.) (Hymenoptera: Scelionidae), Habrobracon hebetor (Say) (Hymenoptera: Braconidae) and Cotesia flavipes (Hymenoptera: Braconidae). Those behaviors were simulated inside a barometric chamber, under controlled conditions of high, stable and low pressure, while other abiotic factor was stable. Barometric pressure clearly influences several insect behavioral activities, but it cannot be generalized to all species. Feeding behavior was distinctively affected for chewing and sucking insects. We observed a decrease in the number of adult salivary sheaths of E. heros submitted to conditions of low barometric pressure. Leaf consumption by Diabrotica speciosa was not affected by barometric pressure. Oviposition behavior was not affected by barometric pressure in any of the species evaluated. The parasitism by Trissolcus basalis did not show influence due to barometric pressure conditions. However, less parasitism of Habrobracon hebetor and Cotesia flavipes was observed under low pressure.

Fortes chuvas e outros eventos climáticos podem afetar o fitness de plantas e insetos. Estudos recentes têm demonstrado que esses organismos são capazes de detectar súbitas variações da pressão barométrica que antecedem a condição climática adversa. Para os insetos, esta percepção é acompanhada de alterações comportamentais aparentemente adaptativas, como a redução do voo e chamamento para cópula. As plantas, por sua vez, respondem com a abertura dos estômatos, de maneira muito semelhante ao estresse hídrico, devido à ativação de rotas bioquímicas associadas ao ácido abscísico. O longo histórico co-evolutivo entre plantas e insetos herbívoros indica que alterações em um organismo reflete na resposta adaptativa do outro. Assim, mesmo que a variação na pressão barométrica afete apenas um dos organismos, a interação inseto-planta deve ser alterada, porém, esta abordagem nunca foi estudada. Utilizando como modelo o milho, Zea mays L. (Poales: Poaceae) e a lagarta-cartucho-do-milho, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), nós investigamos o desempenho alimentar do inseto e defesas induzidas de plantas intactas e com indução pela herbivoria frente a diferentes pressões barométricas. Para isso foram desenvolvidos dispositivos automatizados e os ensaios foram conduzidos dentro de uma câmara barométrica. As lagartas consumiram maiores áreas foliares em pressão baixa do que alta, porém o ganho de peso foi similar nas pressões testadas. Plantas intactas, danificadas pela lagarta e com aplicação do regurgito de S. frugiperda não produziram defesas induzidas pela pressão barométrica, apesar dos tratamentos com indução pelo herbívoro emitirem misturas mais complexa de voláteis comparado às plantas intactas. Além disso, plantas com indução mecânica apresentaram maiores níveis do fitohormônio ácido jasmônico. Nesse contexto, nós hipotetizamos que condições de estresse, como pressão baixa, aumentam o consumo foliar e taxa metabólica das lagartas, resultando em incremento de peso similar a condições não estressantes. Em contrapartida, plantas de milho aparentemente não utilizam a pressão como fator abiótico preditor de alterações climáticas e aumento de herbivoria. Para o melhor do nosso conhecimento, este foi o primeiro estudo a investigar os efeitos da pressão barométrica na interação planta-inseto herbívoro e os resultados obtidos podem repercutir na inclusão da pressão como fator que transmuta ensaios biológicos. / Severe raining and other climatic events can affect plant and insect\'s fitness. Recent studies have shown that these organisms are able to detect sudden barometric pressure variations that generally precede an adverse climatic condition. For insects, this perception is followed by behavioral modifications that are apparently adaptive, as, for instance, the reduction in flights and the calling for mating. Plants, in turn, respond with stomata opening, similar to hydric stress, once biochemical routes associated to the abscisic acid are activated. The historical co-evolutive process between plants and herbivore insects indicate that changes in one organism reflects in the adaptive responses of the other. In that sense, even if the fluctuation of the barometric pressure has direct effects in a single organism, the insect-plant interaction may be altered. However, this approach has never been examined. Taking as models maize plants, Zea mays L. (Poales: Poaceae), and the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) we have investigated the feeding performance and induced defences of intact and herbivore-induced plants under different barometric pressures. For that, we developed automated devices and the assays were conducted inside of a barometric chamber. The fall armyworms larvae consumed greater leaf areas under low than high pressures, but the weight gain was similar among the pressures tested. Wound-induced maize did not displayed defenses by the barometric pressure changes, although the treatments with herbivore induction have emitted more complex volatiles blends when compared to intact maize. Besides that, plants with mechanical damage presented higher levels of the phytohormone jasmonic acid. In this context, we have hypothesized that stress conditions by low pressures increase the leaf area consumption by S. frugiperda, possibly associated to higher metabolic rates of armyworms, resulting in a weight gain similar to the non-stress conditions. On the other hand, corn plants apparently do not use the barometric pressure as an abiotic predictor of climatic changes and increase of herbivory. To the best of our knowlegde this is the first study investigating the barometrtic pressure effects on plant-herbivore insect interaction. Our results may potencially impact in the inclusion of pressure as factor that reshape biological assays.

Made available in DSpace on 2014-08-20T13:44:34Z (GMT). No. of bitstreams: 1 dissertacao_eduardo_venske.pdf: 748978 bytes, checksum: 5e942b59b27d2343cc783ccbc291386d (MD5) Previous issue date: 2013-11-01 / Temperature and light have a complex interaction of plants, and may affect cold tolerance and herbicide selectivity. Two studies were conducted during the 2012 / 2013. In Article I the aim was to evaluate the relationship between temperature and light quantity and quality on the early development of rice cultivars and red rice biotypes. Two experiments were conducted, in the laboratory and in the greenhouse, during the months of July to November, 2012. The factors studied in experiment I were: temperature (25ºC and 18/13ºC); cultivar / biotype (IRGA 424 and PUITA INTA-CL / AV 6716 and AV 6722) and light (white, blue, green, yellow and red, shaders to 86 and 93% and dark). In the second experiment factors were season (August and November); cultivar / biotype (IRGA 424 and PUITA INTA-CL / AV 6716 and AV 6722) and light (white with coating, white, blue, green, yellow and red, shaders to 86 and 93%). The experimental design was in bands for temperature / time of sowing and light, and randomized to cultivar / biotype, with four replications. We evaluated normal seedlings, length of shoot and root, dry weight of shoots and roots and leaf area. Cultivars and biotypes studied have similar behavior against the light and temperature during early development. The light, especially red wave length, has increased tolerance to cold rice. In Article II the objective was to evaluate the effect of sowing date and artificially reducing the luminosity at different stages of plant development on the herbicide selectivity and yield components of rice. The field experiment was carried out in 2012/2013 harvest, and cultivar IRGA 424 was utilized. The factors studied were: sowing season (October 18 and November 09), herbicide (control - hand weeded, bispyribac sodium and penoxsulam) and stage of development of culture with luminosity reduced by 70% [control, seedling (S0-V4), vegetative, reproductive, and the entire cycle]. The experimental design was in bands for sowing date and reduced brightness, and randomized to herbicides, with four replications. Evaluated: plants, stems and panicles per area, herbicide injury, spikelets, filled and empty spikelets per panicle, spikelet sterility, thousand seed weight and yield. The sowing season influences the selectivity bispyribac sodium, and when held near the beginning of the period recommended reduces the productivity of farming. The artificial reduction of light in different phases of the cycle does not affect the selectivity of herbicides bispyribac sodium and penoxsulam on rice. / Temperatura e luz tem um complexo efeito sobre as plantas, podendo afetar a tolerância ao frio e a seletividade de herbicidas. Foram realizados dois estudos, durante os anos de 2012 e 2013. No artigo I o objetivo foi avaliar a relação entre temperatura e quantidade e qualidade de luz sobre o desenvolvimento inicial de cultivares de arroz irrigado e biótipos de arroz vermelho. Foram realizados dois experimentos, em laboratório e em casa de vegetação, durante os meses de Julho a Novembro de 2012. Os fatores estudados no experimento I foram: temperatura (25ºC e 18/13ºC); cultivar/biótipo (IRGA 424 e PUITÁ INTA-CL / AV 6716 e AV 6722) e luz (branca, azul, verde, amarela e vermelha, sombreamentos de 86 e 93% e escuro). No experimento II os fatores foram: época de semeadura (Agosto e Novembro); cultivar/biótipo (IRGA 424 e PUITÁ INTA-CL / AV 6716 e AV 6722); e luz (branca com recobrimento, branca, azul, verde, amarela e vermelha, sombreamentos de 86 e 93%). O delineamento experimental foi em faixas para temperatura / época de semeadura e luz, e inteiramente casualizado para cultivar / biótipo, com quatro repetições. Avaliou-se plântulas normais, comprimento de parte aérea e raiz, massa da matéria seca da parte aérea e de raízes e área foliar. As cultivares de arroz irrigado e biótipos de arroz vermelho estudados têm comportamento semelhante frente à temperatura e luz durante o desenvolvimento inicial. A luz, especialmente no comprimento de onda do vermelho, proporciona aumento na tolerância do arroz ao frio. No artigo II o objetivo do trabalho foi avaliar o efeito da época de semeadura e da redução artificial da luminosidade em diferentes fases do desenvolvimento das plantas, sobre a seletividade de herbicidas e componentes de produtividade do arroz irrigado. O experimento foi conduzido à campo, na safra 2012/2013, e a cultivar utilizada foi IRGA 424. Os fatores estudados foram: época de semeadura (18/outubro e 09/novembro); herbicida (testemunha capinada, bispiribaque sódico e penoxsulam) e fases do desenvolvimento da cultura com luminosidade reduzida de 70% [testemunha, plântula (S0-V4), vegetativo, reprodutivo e todo o ciclo]. O delineamento experimental foi em faixas para época de semeadura e redução de luminosidade, e inteiramente casualizado para herbicidas, com quatro repetições. Avaliou-se: plantas, colmos e panículas por área, fitotoxicidade, espiguetas, espiguetas cheias e vazias por panícula, esterilidade de espiguetas, peso de mil sementes e produtividade. A época de semeadura influencia na seletividade de bispiribaque sódico, sendo que quando realizada próximo ao início do período recomendado reduz a produtividade da cultivar. A redução artificial de luz em diferentes fases do ciclo não afeta a seletividade dos herbicidas bispiribaque sódico e penoxsulam sobre o arroz irrigado.

The influence of abiotic factors on fish distribution in Kaulakiai II water reservoir is investigated in present master thesis. Object of research – fish communities of Kaulakiai II water reservoir, situated near Raseiniai. Aim of the research – to estimate the substantial abiotic factors and to evaluate their influence on fish distribution in Kaulakiai II water reservoir. To meet an aim these tasks were set: to estimate the most abundant fish species in reservoir; to estimate and map the structure of the bottom; to evaluate sensual indicators of alive fish during the experimental fishing; to value the quality of water in Kaulakiai II reservoir and to rate it according the standards applied for water quality in carp ponds; to detect peculiarities of fish distribution in water body and to exclude the substantial abiotic factors that have hold on fish distribution in Kaulakiai II (Kybartėliai) reservoir. Methods of research – logical literary analysis, hydro acoustic surveying, written quiz of local anglers, observational studies, mathematical modeling. Results: the Cyprinid fishes (11 species) were the most abundant in Kaulakiai II reservoir fish communities with overall 15 fish species resident. The bottom structure mainly was silt - 83,2 %, sand and oozy sand, respectively 4,6 and 12,2 %. Fish injures, parasites, diseases had no influence on fish distribution in Kaulakiai II reservoir during the research. Low oxygen concentrations were estimated at the bottom of reservoir... [to full text]

Field and laboratory studies were used to elucidate the factors affecting temporal and spatial variations of species abundance and structure of macroalgal assemblage and environmental variables between fish farming (FFA) and non-fish farming (NFFA) areas in Hsiao-Lu-Chiao island, a coral island in southwestern Taiwan. Four experiments have been approached: 1. field surveys of macroalgal assemblage structure on 5-m and 10-m depth at 3 sampling sites at FFA (FFA1, FFA2 and FFA3) and 1 sampling site at NFFA from September 2004, January 2005 and April 2005; 2.the relationship between abiotic (monthly maximum air temperature, monthly minimum air temperature, monthly mean air temperature, monthly cumulative precipitation, monthly cumulative irradiance, seawater temperature, light extinction coefficient, water motion, and nutrient (NO3-, NO2-, NH4+, SRP, DON, and DOP) and biotic (seaurchin density) factors and spatio-temporal variations in macroalgal structures analyzed by non-parametric multivariate model; 3. Factors affecting macroalgal abundance and structure: (1). Comparison of growth temperature ranges in different species to field temperature fluctuation; (2).Comparison of growth irradiance ranges in different species to field irradiance fluctuation; 4.Herbivore pressure: (1). Spatio-temporal variations of sea urchin abundance and structure of assemblage; (2). Gut contents and food preference of sea urchin experiment; (3). Herbivore exclusion experiment. Macroalgal %cover, biomass, species richness, diversity (H¡¦) and evenness (J¡¦) showed temporal and spatial variations, low values in January 2005 and also low values in the 5 m- and 10 m-depth areas of FFA1 and the 10 m-depth areas of FFA2. The data of k-dominance curve, hierarchical cluster and ANOSIM tests indicate that macroalgal assemblage is different between 4 sampling sites, between 2 depths and between 3 seasons. Ceratodictyon spongiosum is the most important species that separates September and January assemblages from April assemblage and separates the FFA1 and FFA2 assemblages from the FFA3 and NFFA assemblages. BVSTEP analysis shows that nutrients (NO3-, DON, DOP), temperature, monthly cumulative precipitation, and sea urchin density are the factors corresponding to variations of macroalgal assemblages, this correlation is more significant for 5 m-depth assemblage. Fish farming area FFA1and FFA2 assemblage are affect by sea urchin density, temperature and DON. Sea urchin influnces macroalgal abundance and assemblage structure in FFA1 and FFA2. Macroalgal %cover in 5 m-depth area shows a reversal relationship with sea urchin density; however, this relationship is not observed for 10 m-depth area. FFA1 and FFA2 are belong to high grazing pressure sites as indicated by high sea urchin density and exclusion experiment. Sea urchin gut contents and feeding preference test show that sea urchin has strong food selectivity with Hypnea charoides and Gracilaria coronopifolia as the most preferred species. Herbivore exclusion experiment shows that Hypnea charoides and Gracilaria coronopifolia are the species recruited in the cages. Ceratodictyon spongiosum had high biomass in FFA1 and FFA2 in January, which was ¡¥low DOP/high DON¡¦. The coindicence of temporal variations in FFA3 assemblage structure with a change from ¡¦Halimeda opuntia and Boodlea compostia¡¦ ¡÷ ¡¦Amphiroa fragilissima, Corallina phhulifera and Galaxaura oblongata¡¦ ¡÷¡¦Halimeda opuntia and Boodlea compostia¡¦ with low nitrogen/ high phosphorous¡¦ ¡÷¡¦ high nitrogen/ low phosphorous¡¦ ¡÷ ¡¦low nitrogen/ high phosphorous¡¦ suggest a role of ¡¦low nitrogen (NO3-)/high phosphorous (DOP)¡¦ for FFA3 structure modification. NFFA assemblage is controlled by temperature and monthly cumulative precipitation. Monthly cumulative precipitation in September was higher than January and April, in which Boodlea compostia and Gracilaria coronopifolia were dominant algae in September. The temperature growth responses of algae using the continuous-flow outdoor laboratory tank culture system fit their seasonal growth, reflecting the temperature-dependent manner of seasonal variations in abundance. It could be concluded from the present investigation that the structure of benthic macroalgal assemblage in Hsiao-Lu-Chiao island in southwestern Taiwan is affected by predicted natural and pulse disturbances. Temperature fluctuations involve in overall temporal variations in structure. Sea urchin herbivory and nutrient as pulse nutrient modulate the structure in fish farming area while monthly cumulative precipitation is associated with algal structure in non-fish farming area.