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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Distribuição Espacial de Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Erebidae) em soja utilizando Geoestatística / Spatial Distribution of Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Erebidae) in soybean using Geostatistics

Nunes, Eduardo Lima [UNESP] 07 October 2016 (has links)
Submitted by EDUARDO LIMA NUNES null (dunlima@gmail.com) on 2016-11-07T16:51:26Z No. of bitstreams: 1 Dissertação_Eduardo_Lima_Nunes.pdf: 1743275 bytes, checksum: 6e11685b09f43aa5c435f9ae32c20e29 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-10T16:27:04Z (GMT) No. of bitstreams: 1 nunes_el_me_jabo.pdf: 1743275 bytes, checksum: 6e11685b09f43aa5c435f9ae32c20e29 (MD5) / Made available in DSpace on 2016-11-10T16:27:04Z (GMT). No. of bitstreams: 1 nunes_el_me_jabo.pdf: 1743275 bytes, checksum: 6e11685b09f43aa5c435f9ae32c20e29 (MD5) Previous issue date: 2016-10-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A soja é uma das culturas mais relevantes do Brasil, sendo responsável por 49% da área plantada no país, e vem apresentando crescimento quanto sua produção acada ano. Entre as pragas mais importantes da cultura está a lagarta-da-soja, Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Erebidae), responsável por até 100% de desfolha. Para que o controle seja satisfatório, técnicas de manejo devem ser elaboradas com base no conhecimento do comportamento das pragas no campo, como a sua distribuição espacial, por exemplo. Alguns métodos como a geoestatística são eficientes para a elaboração do mapeamento de uma praga ou inimigo natural na cultura, e complementa as estratégias de manejo integrado de pragas, apresentando grande potencial de aplicação para o estudo do comportamento de insetos. O objetivo deste trabalho foi avaliar a distribuição espacial da lagarta-da-soja utilizando técnicas de geoestatística, em uma área plantada com a cultivar M 7908 RR durante a safra agrícola 2014/2015 na FCAV/UNESP Jaboticabal - SP com 0,8 hectares, dividida em 80 parcelas de 100 m² (10 m x 10 m). Em cada parcela foram examinados ao acaso, cinco pontos amostrais semanalmente por meio da técnica do pano de batida em 2 metros lineares durante os estádios vegetativo e reprodutivo da cultura. A análise geoestatística permite a elaboracão de semivariogramas experimentais, com ajuste de modelos matemáticos, com o objetivo de estudar a dependência espacial das pragas na área em estudo. Observou-se que a lagarta-da-soja varia sua população quando há altas temperaturas e precipitação quase nula, que pode estar relacionado com más condições de tempo para o aparecimento de fungos entomopatogênicos, fazendo com que essa flutuação no decorrer das datas de amostragem ao invés de manter um declínio constante, aumente em um momento que existam essas condições citadas anteriormente de tempo seco e quente. A lagarta se comporta de maneira agregada, fato comprovado pela evidente existência de dependência espacial com alcance variando de 7 a 55,42 m. Nas amostragens com baixa infestação, não foi possível verificar a existência de dependência espacial. / Soybran is one of the most important crops in Brazil, accounting for 49% of the planted area of grains in the country, and has shown growth as its production for each year. Among the most important pests of culture is the velvetbean-caterpillar, Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: erebidae), responsible for up to 100% defoliation. So that the control is satisfactory, management techniques should be developed based on knowledge of the behavior of pests in the field, as their spatial distribution, for example. Methods such as geostatistical are efficient for the development of mapping a plague or natural enemy in the culture, and complements the integrated management strategies pest, with great potential for application to the study of insect behavior. The objective of this study was to evaluate the spatial distribution of velvetbean-caterpillar using geostatistics techniques in a planted area with grow crops M 7908 RR during the 2014/2015 in FCAV/UNESP Jaboticabal - SPwith 0,8 hectare, divided into 80 plots of 100 m² ( 10 mx 10 m). In each plot were examined at random five sampling points weekly through technical beat cloth on 2 meters during the vegetative and reproductive stages of culture. The geostatistical analysis allows the elaboration of experimental semivariogram, with adjustment of mathematical models in order to study the spatial dependence of the pests in the study area . It was observed that the soybean-caterpillar varies its population when there are high temperatures and almost no precipitation, which may be related to bad weather conditions for the onset of entomopathogenic fungi, making this fluctuation during the sampling dates when instead of maintaining a steady decline, increase at a time when there are those above conditions dry and hot weather. The caterpillar behaves in aggregate, a fact evidenced by the apparent existence of spatial dependence with a range varying from 7 to 55,42 m. In the samples with low infestation, could not verify the existence of spatial dependence. / CAPES: 132264/2014-5
32

Avaliação da eficácia do soro antilonômico na reversão da síndrome hemorrágica causada por contado com lagartas da Lonomia obliqua (Lepidoptera, Saturniidae)

Caovilla, Jairo José January 2003 (has links)
A síndrome hemorrágica causada por contato com lagartas da Lonomia obliqua tem alcançado proporções epidêmicas no sul do Brasil. O objetivo deste estudo foi avaliar a eficácia de diferentes doses do soro antilonômico (SALon) no tratamento de pacientes que tiveram contato com lagartas da Lonomia obliqua. Um ensaio clínico prospectivo, randomizado, duplo-cego foi realizado no hospital universitário São Vicente de Paulo de Passo Fundo, RS, Brasil. Entre janeiro de 2000 a março de 2002, 44 pacientes portadores de síndrome hemorrágica grau I e grau II foram randomizados em dois grupos: Grupo A: 22 pacientes que receberam uma dose de 10,5mg (três ampolas) de SALon; Grupo B: 22 pacientes que receberam uma dose de 17,5mg (cinco ampolas) de SALon. A eficácia do tratamento foi avaliada pelo tempo necessário para normalização dos fatores de coagulação sangüínea, freqüência de reações adversas e dias de hospitalização. Não houve diferença no quadro clínico e nas alterações laboratoriais entre os dois grupos. O tempo médio para normalizar o tempo de coagulação foi de 15,3 ± 6,6 h e de 19,1 ± 8 h nos grupos A e B, respectivamente (P = 0,09). A freqüência de reações adversas e o tempo de internação hospitalar foram semelhantes entre os dois grupos. O uso do soro antilonômico foi efetivo e bem tolerado. Doses substancialmente menores das preconizadas podem ser suficientes para reverter à síndrome hemorrágica causada pelo envenenamento por contato com lagartas da Lonomia obliqua. / The hemorrhagic syndrome caused by contact with Lonomia obliqua caterpillars has reached epidemic proportions in southern Brazil. This study aimed at assessing the efficacy of different dosages of an antilonomic serum (SALon) in the treatment of patients who had accidental contact with Lonomia obliqua caterpillars. A randomized, double-blinded, prospective clinical trial was conducted at São Vicente de Paulo Hospital, a tertiary hospital in Passo Fundo, Brazil. From January 2000 to April 2002, 44 patients with grade I or II hemorrhagic syndrome were randomly assigned to either group A (22 patients treated with 10,5mg total dose, 3 vials of SALon) or group B (22 patients treated with 17,5mg total dose, 5 vials of SALon). Treatment efficacy was assessed according to time necessary for blood coagulation to go back to normal, incidence of adverse reactions, and hospitalization time. There were no differences in clinical picture and laboratory findings between the two groups. Mean time for coagulation to go back to normal was 15.3±6.6 h and 19.1±8 h in groups A and B, respectively. Adverse reactions and hospitalization time were similar in both groups. SALon was effective and well tolerated. Results suggest that substantially smaller doses than those routinely prescribed may be sufficient for the treatment of envenoming by Lonomia caterpillars.
33

Avaliação da eficácia do soro antilonômico na reversão da síndrome hemorrágica causada por contado com lagartas da Lonomia obliqua (Lepidoptera, Saturniidae)

Caovilla, Jairo José January 2003 (has links)
A síndrome hemorrágica causada por contato com lagartas da Lonomia obliqua tem alcançado proporções epidêmicas no sul do Brasil. O objetivo deste estudo foi avaliar a eficácia de diferentes doses do soro antilonômico (SALon) no tratamento de pacientes que tiveram contato com lagartas da Lonomia obliqua. Um ensaio clínico prospectivo, randomizado, duplo-cego foi realizado no hospital universitário São Vicente de Paulo de Passo Fundo, RS, Brasil. Entre janeiro de 2000 a março de 2002, 44 pacientes portadores de síndrome hemorrágica grau I e grau II foram randomizados em dois grupos: Grupo A: 22 pacientes que receberam uma dose de 10,5mg (três ampolas) de SALon; Grupo B: 22 pacientes que receberam uma dose de 17,5mg (cinco ampolas) de SALon. A eficácia do tratamento foi avaliada pelo tempo necessário para normalização dos fatores de coagulação sangüínea, freqüência de reações adversas e dias de hospitalização. Não houve diferença no quadro clínico e nas alterações laboratoriais entre os dois grupos. O tempo médio para normalizar o tempo de coagulação foi de 15,3 ± 6,6 h e de 19,1 ± 8 h nos grupos A e B, respectivamente (P = 0,09). A freqüência de reações adversas e o tempo de internação hospitalar foram semelhantes entre os dois grupos. O uso do soro antilonômico foi efetivo e bem tolerado. Doses substancialmente menores das preconizadas podem ser suficientes para reverter à síndrome hemorrágica causada pelo envenenamento por contato com lagartas da Lonomia obliqua. / The hemorrhagic syndrome caused by contact with Lonomia obliqua caterpillars has reached epidemic proportions in southern Brazil. This study aimed at assessing the efficacy of different dosages of an antilonomic serum (SALon) in the treatment of patients who had accidental contact with Lonomia obliqua caterpillars. A randomized, double-blinded, prospective clinical trial was conducted at São Vicente de Paulo Hospital, a tertiary hospital in Passo Fundo, Brazil. From January 2000 to April 2002, 44 patients with grade I or II hemorrhagic syndrome were randomly assigned to either group A (22 patients treated with 10,5mg total dose, 3 vials of SALon) or group B (22 patients treated with 17,5mg total dose, 5 vials of SALon). Treatment efficacy was assessed according to time necessary for blood coagulation to go back to normal, incidence of adverse reactions, and hospitalization time. There were no differences in clinical picture and laboratory findings between the two groups. Mean time for coagulation to go back to normal was 15.3±6.6 h and 19.1±8 h in groups A and B, respectively. Adverse reactions and hospitalization time were similar in both groups. SALon was effective and well tolerated. Results suggest that substantially smaller doses than those routinely prescribed may be sufficient for the treatment of envenoming by Lonomia caterpillars.
34

Corporative strategy in a global industry joy global faces Caterpillar's acquisition of bucyrus

Fonseca, Carlos E. 07 1900 (has links)
Tesis para optar al grado de Magíster en Administración / Autor no autoriza el acceso a texto completo de su tesis en el Portal de Tesis Electrónicas de la U. de Chile. / Mike Sutherlin, CEO of Joy Global Inc. (“JOY”), a global mining equipment manufacturer, was having lunch, in downtown Milwaukee, Wisconsin, with his wife, in November of 2010 when his cell phone began ringing. He hesitated answering, but recognizing the name, picked up to hear surprising news. It was a courtesy call from a friend at Caterpillar Inc. (“CAT”), the $85 Billion USD juggernaut, letting him know that CAT had just purchased JOY’s cross town rival, Bucyrus International, Inc. (“BI”), for $8.8B USD. JOY and BI were 2 Milwaukee, Wisconsin based mining equipment manufacturers who competed head to head on a worldwide stage. Evenly matched, with a market cap around $7B USD each, these two companies had spared in the surface and underground mining equipment market for heavy duty extraction mining equipment for over a hundred years since their founding in 1888 and 1889, respectively. All of a sudden, with this acquisition, what had always been a cross town rivalry would take on new proportions. CAT was the undisputed world wide heavy machinery giant with a market cap 10 times the size of JOY. Regarding the acquisition, Sutherlin comments, “Instead of a smaller competition across town all of a sudden this changed the world for us.” CAT brought to the table revenues which were 12 times larger than JOY, a global brand that stood for reliable heavy machinery, exceptional service through its army of worldwide distributors, and the ability to win deals by financing equipment through CAT financial. Sutherlin´s team had just put the finishing touches on their strategic plan for 2010. The exercise had reaffirmed some of JOY´s strategies, such as a continued commitment to focus solely in the mining equipment industry (versus including construction and farming equipment markets like CAT), a direct sales and service go to market model (versus third party distributors like CAT), and a focus on premium products with premium pricing (versus wining deals on price like BI). The plan also called for some changes such as moving beyond the dependence on a single product for their surface mining division and a move beyond coal specific products for its underground division. Would this strategy need to be revised? Would the plan withstand this new challenge? Sutherlin knew it was time to get his leadership team together, circle the wagons, and figure out, what, if anything, JOY could do to respond to this new competitive threat from CAT.
35

Analysis of poplar (Populus trichocarpa x P. deltoides) inducible defense response against insect herbivores

Major, Ian 30 March 2010 (has links)
In order to analyze the inducible defense response of hybrid poplar (Populus trichocarpa x P. deltoides), macroarrays were used to profile transcript patterns elicited by wounding and by regurgitant from forest tent caterpillar (FTC; Malacosoma disstria), a poplar defoliator. FTC regurgitant proved to be a potent elicitor of defense gene expression and was shown to contain the insect-derived elicitor volicitin. Comparison of inducible defense responses elicited by FTC regurgitant and wounding with pliers revealed qualitatively similar responses in terms of transcript accumulation. Extensive overlap was also observed in the sets of induced genes from locally- and systemically-induced leaves. Systemic responses were further investigated and shown to also be inducible in roots, which implies shoot-root systemic signaling. Comparative macroarray analysis showed similarities between inducible responses in leaves and roots, including genes that encode previously identified leaf herbivore defense genes. The macroarray analysis also established a suite of marker genes for future studies of herbivore defense in poplar, many of which may play key roles in the defense response and are candidates for further study. Among these genes were several inducible Kunitz trypsin inhibitors (KTIs), which were investigated further with biochemical analyses. The sequenced poplar genome was used to select KTI genes that represent the diversity of this family. Recombinant proteins were generated and showed that the poplar KTI genes encode functional proteinase inhibitors and that they are functionally distinct, i.e. they have specific proteinase substrate preferences. Moreover, wounding increases accumulation of KTI proteins, as well as protease inhibitor activity in leaves, supporting a defensive role for this protein family. These proteins were therefore tested for their ability to inhibit insect digestive proteases from FTC and bertha armyworm. The poplar KTIs tested all inhibited at least some protease activity from FTC midgut extracts. The strongest inhibitor of FTC proteases, TI3. was further tested in bioassays and shown to reduce larval growth of FTC when incorporated into insect diet. confirming that this KTI functions as an anti-herbivore protein. In addition, analysis of FTC midguts from T13 feeding experiments showed that larvae responded to TI3 by producing more gut proteases. This hyperproduction of proteases may exacerbate the antinutritive effects of TI3 by reducing pools of essential amino acids.
36

Safe and Sound: Studies on the Function and Evolution of Defence Sounds in Bombycoidea Caterpillars

Dookie, Amanda January 2017 (has links)
Defence sounds are widespread and diverse amongst insects. Despite their ubiquity and variability, hypotheses explaining their functions and evolutionary origins have been understudied. My thesis focused on these topics using silk and hawkmoth Bombycoidea caterpillars as a model system. In Chapter Two I investigated why defence sounds have evolved in some caterpillars but not others by testing the hypothesis that large body size is a factor in the evolution of defence sounds. To test this hypothesis, I followed the development of defence sounds in four Bombycoidea species from hatching to pupation. I predicted that early instars would not produce defence sounds, and that within sound producing instars defence sounds would be more likely to occur in larger caterpillars. Results showed that defence sounds were absent in the first and second instar, and that they developed in the third through to the fifth instar in all species. Moreover, the onset of sound production occurred when all species were the same relative size (~1.12 g, ~26.37 mm), despite the fact that the species differed in their final instar size. I concluded that early instar caterpillars do not make defence sounds, and that there is a critical size when defence sounds develop. I further tested the hypothesis that smaller caterpillars do not have enough energy to make defence sounds, by analyzing the relationship between size and several temporal characteristics of the sounds. I predicted that smaller caterpillars would signal less than larger caterpillars, and produce shorter signal units and trains, with lower duty cycles. Results partly supported the hypothesis, showing that in two species there was a positive relationship between size and the number of units produced within two seconds following an attack, the mean number of units per train, and the mean duration of the units in one species. I also tested the hypothesis that sounds of small caterpillars are not in the hearing range of predators. I predicted that there would be a relationship between caterpillar size, and the sound pressure levels and dominant frequencies of the sounds. Results showed no significant relationships with dominant frequencies or sound pressure levels and size. I concluded that the caterpillars made sounds that were within the hearing range of major predators from the onset of sound production. In Chapter Three I followed the other antipredator defences of the four species throughout development. I investigated whether the frequency of defences changed with instar. I found that the caterpillars employed up to seven different secondary defences throughout development. In one species the frequency of dropping and major thrashing increased in the late instars, and in a different species the frequency of regurgitation increased. I concluded that in some cases defence sound production accompanies other secondary defences that increase with the size of caterpillars during development. In Chapter Four I tested the hypothesis that the defensive whistle of the walnut sphinx caterpillar, Amorpha juglandis (Sphingidae: Sphinginae), functions to startle birds. I predicted that the birds would startle to the sounds, and habituate upon repeated exposure within a trial. Results showed that play-back recordings of the whistles elicited a startle response in captive red-winged blackbirds (Agelaius phoeniceus) and caused them to hesitate and/or flee from prey. I concluded that the whistles function as a startle display. Together, the experiments conducted within my thesis addressed important outstanding questions regarding the evolutionary origins of defence sounds in caterpillars, and their functions in predator-prey interactions.
37

Zvýšení pružnosti zážehového přeplňovaného motoru na CNG / Improving Performance of Turbocharged CNG Engine

Janoušek, Michal January 2012 (has links)
The aim of diploma thesis is the design of fuel system for the Caterpillar twelve cylinder spark ignited turbocharged engine. The fuel system is designed for sequential electronic controlled gas injection into intake manifold. Computational model of the engine was calculated in Lotus Engine simulation software. CFD analysis of mixing CNG with air was computed in Star CCM+ software.
38

Hybrid Control in Multi-Robot Systems and Distributed Computing

Jamshidpey, Aryo 06 January 2023 (has links)
Multi-agent systems (MAS) have been of interest to many researchers during the last decades. This thesis focuses on multi-robot systems (MRS) and programmable matter as two types of MAS. Regarding MRS, the focus is on the 'mergeable nervous system' (MNS) concept which allows the robots to connect to one another and establish a communication network through self-organization and then use the network to temporarily report sensing events and cede authority to a single robot in the system. Here, in a collective perception scenario, we experimentally evaluate the performance of an MNS-enabled approach and compare it with that of several decentralized benchmark approaches. We show that an MNS-enabled approach is high-performing, fault-tolerant, and scalable, so it is an appropriate approach for MRS. As a goal of the thesis, using an MNS-enabled approach, we present for the first time a comprehensive comparison of control architectures in multi-robot systems, which includes a comparison of accuracy, efficiency, speed, energy consumption, scalability, and fault tolerance. Our comparisons provide designers of multi-robot systems with a better understanding for selecting the best-performing control depending on the system's objectives. Additionally, as a separate goal, we design a high-level leader based programmable matter, which can perform some basic primitive operations in a grid environment, and construct it using lower-level organisms. We design and implement deterministic algorithms for "curl" operation of this high-level matter, an instance of shape formation problem. We prove the correctness of the presented algorithms, analytically determine their complexity, and experimentally evaluate their performance.
39

Estimating Uncertainties in the Joint Reaction Forces of Construction Machinery

Allen, James Brandon 05 June 2009 (has links)
In this study we investigate the propagation of uncertainties in the input forces through a mechanical system. The system of interest was a wheel loader, but the methodology developed can be applied to any multibody systems. The modeling technique implemented focused on efficiently modeling stochastic systems for which the equations of motion are not available. The analysis targeted the reaction forces in joints of interest. The modeling approach developed in this thesis builds a foundation for determining the uncertainties in a Caterpillar 980G II wheel loader. The study begins with constructing a simple multibody deterministic system. This simple mechanism is modeled using differential algebraic equations in Matlab. Next, the model is compared with the CAD model constructed in ProMechanica. The stochastic model of the simple mechanism is then developed using a Monte Carlo approach and a Linear/Quadratic transformation method. The Collocation Method was developed for the simple case study for both Matlab and ProMechanica models. Thus, after the Collocation Method was validated on the simple case study, the method was applied to the full 980G II wheel loader in the CAD model in ProMechanica. This study developed and implemented an efficient computational method to propagate computational method to propagate uncertainties through "black-box" models of mechanical systems. The method was also proved to be reliable and easier to implement than traditional methods. / Master of Science
40

Influência da agregação larval na história de vida de Ascia monuste orseis (Godart, 1819) (Lepidoptera, Pieridae) / Influence of larval aggregation on life-history traits of Ascia monuste orseis (Godart, 1819) (Lepidoptera, Pieridae)

Santana, Alessandra Figueiredo Kikuda 25 April 2012 (has links)
A agregação em insetos centra-se nas vantagens relativas ao forrageio e no aumento da defesa contra predadores. Além disso, agregações de ovos podem beneficiar-se pelo aumento nas taxas de eclosão larval. Neste trabalho, foram testadas as hipóteses de que agregações de Ascia monuste orseis (Godart, 1819) (Lepidoptera: Pieridae) uma espécie que se alimenta em agregações larvais em plantas da família Brassicaceae - conferem benefícios à performance larval e adulta, na assimilação de alimento pelas larvas, na viabilidade dos ovos e na proteção larval contra inimigos naturais. A possibilidade de um dado comportamento do grupo resultar em maior ataque por inimigos naturais também foi avaliada, bem como um padrão comportamental defensivo em resposta aos inimigos naturais. Para tanto, quatro tratamentos de diferentes tamanhos de agregações larvais foram formados (1, 7, 15 e 30 larvas) para avaliar a performance e a assimilação de alimento em laboratório. Em campo, três tratamentos foram formados (1, 10 e 50 larvas) para testar o efeito do tamanho do tamanho do grupo na predação e parasitismo. A performance do estágio de ovo foi examinada em posturas de tamanhos variados em casa de vegetação. Larvas gregárias desenvolveram-se mais rápido nos ínstares iniciais e tornaram-se fêmeas mais fecundas em comparação às solitárias; entretanto, larvas solitárias apresentaram maior tamanho do que as gregárias. A sobrevivência não diferiu entre os tratamentos em laboratório. Foi observado um menor consumo per capita de alimento por larvas gregárias, sem custos para a assimilação de alimento. A viabilidade dos ovos aumentou com o tamanho da agregação de ovos, comprovando o benefício da agregação larval na fase de ovo. A menor predação per capita em agregações larvais maiores conferiu uma maior proteção às larvas de A. monuste orseis contra predadores e parasitoides, através do efeito da diluição do ataque entre os indivíduos do grupo. O parasitoidismo foi mais expressivo em larvas de primeiros ínstares, enquanto que larvas mais tardias foram mais atacadas por predadores, independente do tamanho da agregação. Por fim, eventos comportamentais que envolvem movimentação da cabeça como exploração e alimentação foram mais perigosos para as larvas de A. monuste orseis em comparação ao repouso e deslocamento, semelhantemente a espécies de hábito solitário. Eventos comportamentais supostamente defensivos foram observados em todos os ínstares e tratamentos. As vantagens da agregação em A. monuste orseis mostraram-se especialmente importantes no estágio de ovo e primeiros ínstares, pela diminuição da mortalidade de ovos e vulnerabilidade larval aos inimigos naturais. Esses benefícios provavelmente sobrepõem-se aos custos, como a competição por interferência observada entre as larvas no final do desenvolvimento. Nossos resultados mostram que o malogro dos ovos e os efeitos dos inimigos naturais constituem fortes pressões seletivas na manutenção da agregação de ovos e larval em A. monuste orseis, a qual confere uma melhor performance do ponto de vista bi-trófico, bem como maior probabilidade de sobrevivência individual sob o ponto de vista tri-trófico. / In insects, the gregarious habit has been shown to improve foraging and defense against predation to both larval and adult stages. Egg clusters could also be beneficial through increased larval hatching. In this study, we tested the hypothesis that egg clusters and larval aggregations of the neotropical butterfly Ascia monuste orseis (Godart, 1819) (Pieridae) - a subspecies that uses Brassicaceae as hosts - lead to several benefits from both bi- and tri-trophic perspectives. Larval and adult performances, food assimilation by the larvae, egg viability, as well as protection against natural enemies were assessed from individuals reared either isolated or aggregated. The behavior of larval aggregations was also examined with respect to predation risk, as well as the corresponding larval defensive behaviors after enemy attack. Four treatments with different larval aggregation sizes were assigned (1, 7, 15 e 30 larvae) to assess larval performance and food utilization in the laboratory. In the field, three treatments were assigned (1, 10 e 50 larvae) to evaluate the effects of group size on predation and parasitoidism. Egg performance was examined through egg clusters of different sizes in a greenhouse. Gregarious larvae developed faster, especially in early instars, and became more fecund females than solitary larvae; however, the latter attained larger body size than the former. Under laboratory conditions, survival did not differ among treatments. Lower food ingestion per capita was observed in gregarious larvae, with no cost in food assimilation. The viability of eggs increased as egg aggregation size increased. The lower per capita predation in larger larval aggregations than smaller groups conferred higher protection to A. monuste orseis larvae against natural enemies, through the dilution effects among individuals of the group. Parasitoidism was more intense in small-sized larvae while late instars were more susceptible to predators, regardless of aggregation size. Similar to species with solitary habit, behavioral events which involved head movements as searching and feeding were more dangerous to A. monuste orseis larvae compared to resting and walking. Presumed defensive behaviors were observed in all instars and treatments. Thus, the benefits of aggregation in A. monuste orseis can be seen especially in the egg stage and in first instars, as it reduces egg mortality and larval vulnerability to natural enemies. These benefits probably overcome some costs, such as interference competition in the late instars. Taken together, the results show that egg failure and top-down effects constitute selective pressures in maintaining egg and larval aggregation in A. monuste orseis, by providing better performance from a bi-trophic perspective and increased probability of individual survival from a tri-trophic perspective when compared to solitary individuals.

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