This work studied distastefulness of alkaloids of eight ladybird species (Adalia bipunctata, Calvia quatuordecimguttata, Coccinella septempunctata, Cynegetis impunctata, Exochomus quadripustulatus, Halyzia sedecimguttata, Harmonia axyridis, Psyllobora vigintiduopunctata) for ants Lasius niger. The reaction to extracts of various ladybird species isn´t corelated with their size. There is a weak relationship of distastefulness on ladybird coloration.

Ladybugs are often used in biological control, because of their predatory way of life and potential ability to control many insect pests. So far, a number of studies was performed on this family, on their hunting strategies, other life history strategies, population dynamics, dependence of their distribution in time and space on the abundance of prey etc. However, the temporal changes in species composition and relative or absolute abundance of ladybugs were not yet examined along an altitudinal gradient. This is why I have focused my work on these dependencies. I tested the following hypothesis: overwintering sites in Coccinellidae are usually located at lower altitudes, where the individuals eventually attack their prey on the earliest budding trees; as season goes on, ladybugs follow the trends in environmental conditions and food and move to higher located sites; at the end of the season, ladybugs return back to their overwintering sites. In the research area in the Beskydy Mountains, 12 experimental sites were selected, evenly spaced along an elevational gradient of 350-482 m above sea level at each location. During the season, 12 measurements at two-week intervals were performed, each containing 2x300 sweeps. A total of 3064 of ladybug individuals were collected, belonging to 11 species. The...

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Chinese cabbage (Brassica chinensis L.) has been indicated, along with other vegetables, as an excellent alternative for Brazilian agribusiness, especially those grown in organic production system. Regarding to insect pests, that damage this crop, it shows the chrysomelid Microtheca semilaevis Stal, which cause defoliation on plants during larval and adult stages. Thus, the present work was developed to study bioecology aspects of M. semilaevis, obtaining information about biology, food preference and consumption, natural enemies and population fluctuation. In laboratory and under controlled conditions, biological aspects, such as duration, feasibility and measurement of the immature and adults; and fertility and longevity of adults were evaluated to determine fertility life table. Also in laboratory, experiments to evaluate food consumption and feeding preference of these beetles were conducted fed on leaf discs of four host varieties: Chinese cabbage, watercress (Nasturtium officinale L.), arugula (Eruca sativa L.) and mustard (Brassica juncea C.). Under field conditions, samples of natural enemies of the different development stages were taken in cultivation, besides studying the population dynamics of Microtheca spp. during Chinese cabbage crop cycle in Santa Maria, RS. The eggs have an average incubation period of 6.13 ± 0.04 days and average survival rate of 76.00%. M. semilaevis presents four larval instars, and the average duration of each instar were 2.86 ± 0.06, 1.97 ± 0.05, 1.80 ± 0.06 and 2.43 ± 0.07 days. The cycle from egg to adult is approximately 22 days. Life table fertility determined an increasing capacity of 166 times in each generation, and the average length of a generation of 49 days and finite rate of increase of 1.116 individuals / week. Larvae prefer watercress among crucifers tested, while adults prefer watercress and arugula, with lower consumption for both development stages ranging from Chinese cabbage and mustard. The peak population of larvae and adults in the field occurred in October. There was no emergence of parasitoids on larval and adult stages. However, predators were found belonging to four families with a predominance of Coccinellidae and Pentatomidae and also Vespidae and Reduviidae were found in smaller numbers. The results in this work provide subsidies that might be used for the establishment of integrated management strategies for M. semilaevis. / A couve-chinesa (Brassica chinensis L.) tem sido apontada, juntamente com outras hortaliças, como uma excelente alternativa para o agronegócio brasileiro, em especial aquelas cultivadas no modo de produção orgânica. Com relação aos insetos-praga que danificam a cultura, destaca-se o crisomelídeo Microtheca semilaevis Stal, causando desfolhamento nas plantas durante as fases larvais e adulta. Assim, o presente trabalho teve como objetivo estudar aspectos bioecologicos de M. semilaevis, obtendo informações sobre biologia, preferência e consumo alimentar, inimigos naturais e flutuação populacional. Em laboratório e sob condições controladas, foram avaliados aspectos biológicos, como a duração, a viabilidade e a medição de imaturos e adultos; também, a fecundidade e a longevidade dos adultos, para permitir a elaboração da tabela de vida de fertilidade. Ainda em laboratório, experimentos avaliaram o consumo e a preferência alimentar desses coleópteros alimentados com discos foliares de quatro variedades hospedeiras: couvechinesa, agrião (Nasturtium officinale L.), rúcula (Eruca sativa L.) e mostarda (Brassica juncea C.). Em condições de campo, foram realizadas coletas em cultivo dos inimigos naturais das diferentes fases de desenvolvimento, além de estudar a flutuação populacional de Microtheca spp. no ciclo da cultura de couve-chinesa em Santa Maria, RS. Os ovos apresentam um período de incubação médio de 6,13±0,04 dias e viabilidade média de 76,00%. M. semilaevis apresenta a fase larval com quatro instares, sendo que a duração média de cada ínstar foi de 2,86±0,06; 1,97±0,05; 1,80±0,06 e 2,43±0,07 dias. O ciclo de ovo a adulto foi de, aproximadamente, 22 dias. Através da tabela de vida de fertilidade determinou-se uma capacidade de aumento de 166 vezes a cada geração, sendo a duração média de uma geração de 49 dias e a razão finita de aumento de 1,116 indivíduos/semana. Larvas preferem agrião dentre as brássicas testadas, sendo que adultos preferem agrião e rúcula, com menor consumo, para ambas as fases de desenvolvimento, variando entre couve-chinesa e mostarda. Os picos populacionais de larvas e adultos, no campo, ocorreram no mês de outubro. Não houve emergência de parasitoides nas fases larval e adulta. Porém, foram encontrados predadores pertencentes a quatro famílias com predomínio de Coccinellidae e Pentatomidae, sendo Vespidae e Reduviidae presentes em menor número. Os resultados encontrados no presente trabalho fornecem subsídios que podem ser utilizados para o estabelecimento de estratégias de manejo integrado de M. semilaevis.

Les causes évolutives de certaines formes de vie en groupe sont bien identifiées mais pas celles des agrégations de diapause des arthropodes (rassemblements monospécifiques d'adultes dans des sites à localisation constante). Dans cette thèse, j'ai testé si, selon l'hypothèse du lek caché, les arthropodes se rassemblent pour trouver leurs partenaires sexuels chez la coccinelle Hippodamia undecimnotata. J'ai montré que les coccinelles se rassemblent dans des endroits avec un repère proéminent et où le risque de pesticides est faible, puis que les conditions abiotiques dans les sites sont défavorables à la survie des coccinelles. Ensuite, j'ai mis en évidence l'occurrence de nombreux accouplements dans les sites d'agrégation. Enfin, j'ai montré que ces accouplements sont peu coûteux en énergie pour les femelles, qui conservent de l'énergie pour les comportements post-agrégation. Cette thèse atteste que les agrégations de diapause font partie du système de reproduction des arthropodes. / The evolutionary significance of some kinds of group living are well-known, some others such as the diapause aggregations remain poorly known although widespread. In this thesis, I tested if the arthropods form diapause aggregations to find their mates according to the hidden lek hypothesis with the ladybird Hippodamia undecimnotata. By using a Species Distribution Model, I showed that ladybirds aggregate in places with a prominent object and where the risk of being sprayed by pesticides is low. Then, I highlighted that abiotic conditions are unfavourable to ladybirds' survival. In a third part, I found that mating is widespread activity in the aggregation sites. Finally, I showed that energetic costs linked to mating are low, and thus allow the ladybirds to disperse and display post aggregations behaviour. This thesis shows that the diapause aggregations are part of the mating system of the arthropods and that sexual selection can be a driver of the evolution of diapause aggregations.

Introduced species, like the lady beetle Harmonia axyridis, have been linked to declines of native species through mechanisms including intraguild predation and competitive superiority. However, competitive differentials between species may be mitigated if subdominant species can utilize resources that dominant species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to H. axyridis. My goal was to investigate use of this resource by both H. axyridis and other lady beetles, to determine whether these aphids might be an exploitable resource for subdominant lady beetle species. I first examined the behavioral responses of adult and larval H. axyridis to toxic strains of A. craccivora. I found that adults invested less time and laid fewer eggs with toxic than nontoxic aphids, and larvae consumed toxic aphids at a slower rate, often refusing them as a food source. I then tested whether six other lady beetle species could use the aphids, monitoring larval development in no-choice environments with different strains of A. craccivora. All species showed increased survival and development rates relative to H. axyridis on toxic aphid strains, suggesting these aphids may allow other coccinellid species to experience competitive release from the otherwise dominant H. axyridis.

Native to Asia, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is an invasive non-native ladybird in Europe and North America, where it was widely introduced as a biological control agent of aphids and coccids. There were three main objectives of this study: firstly, to investigate the spread and distribution of H. axyridis in Europe from the start of the invasion process; secondly, to study its ecology in Great Britain; and thirdly, to examine its effects on native ladybirds in Britain. In Europe, collaborations with a network of scientists allowed the collation of H. axyridis occurrence data from across the continent. In Great Britain, a web-based public survey (www.harlequin-survey.org) was used, leading to the receipt of over 10,000 verified records of H. axyridis between 2004 and 2008. National land cover data enabled the habitats used by H. axyridis to be identified across Great Britain. These datasets were analysed in order to study the spread and ecology of H. axyridis in Europe and Britain. Fieldwork over a three year period (2006 to 2008) was carried out to examine changes in ladybird species assemblages during the invasion phase of H. axyridis in eastern England. Laboratory work was conducted to detect intraguild predation by H. axyridis, through PCR analyses of gut contents of field-collected ladybirds. In Europe, H. axyridis has spread since 2001 at the rate of approximately 200km yr-1. It has become established in at least 23 European countries. The established range extends from Norway in the north to southern France in the south, and from Ukraine in the east to Great Britain in the west. In the first five years of establishment H. axyridis spread north through Britain at the rate of 105km yr-1 and west at the rate of 145km yr-1. Evidence of the production of two generations per year was found, giving H. axyridis an advantage over most native ladybirds in Britain. Although H. axyridis was very common in urban habitats, it increasingly used semi-natural habitats. In addition, whilst the species was most common on deciduous trees, it was increasingly found on herbaceous plants. Aceraceae, Rosaceae and Malvaceae were the dominant plant families used by H. axyridis, especially for breeding. In eastern England H. axyridis increased from 0.1% to 40% of total ladybirds in three years, whilst native aphidophagous ladybirds declined from 84% to 41% of total ladybirds in the same period. Three species in particular experienced declines: Adalia 2-punctata, Coccinella 7-punctata and Propylea 14-punctata. Harmonia axyridis was the most abundant species by the end of the study. Detection of intraguild predation by one coccinellid on another, in the field in Europe, was shown for the first time using PCR techniques: A. 2-punctata DNA was detected in the gut of one of 112 field-collected H. axyridis. Harmonia axyridis has spread very quickly since 2001 and has become one of the most widely distributed coccinellids in Europe. Populations of native aphidophagous ladybirds were negatively affected by the arrival of H. axyridis, partly through intraguild predation.

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Submitted by (edna.saturno@ufrpe.br) on 2016-11-21T15:38:16Z No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) / Made available in DSpace on 2016-11-21T15:38:16Z (GMT). No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) Previous issue date: 2012-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Insecticides and natural enemies are used or preserved sharing the same objective of reducing pest populations in the crop ecosystems. However, the examples of simultaneous action with additive or synergistic outcomes are rare. The resistance in lady beetles to the insecticide lambda-cyhalothrin, which is widely used against pests nontarget of the lady beetles, can result in simultaneous use of chemical and at least partial biological control. In this study was investigated the susceptibility of 28 Brazilian and 2 North American lady beetle populations to the lambda-cyhalothrin. Furthermore, studies were conducted to characterize the mechanisms and the inheritance of resistance for those species exhibiting high levels of tolerance to lambda-cyhalothrin. Among the studied populations resistance ratios were determined varying from 115- to 38-fold in four populations of Eriopis connexa Germar and 220-fold in one North American population of Hippodamia convergens Guérin-Méneville; therefore, there is strong evidence for selection of resistance to lambda-cyhalothrin in the field. Further, 22 and 96% of the Brazilian populations exhibited LD50 value that exceed the recommended lambda-cyhalothrin dose to spray cotton fields and the LD50 calculated for boll weevil (Anthonomus grandis Boh.). The lady beetle E. connexa exhibited autosomal and incompletely dominant inheritance of resistance to lambda- cyhalothrin; while the knockdown effect for H. convergens was sex linked and incompletely recessive. The tests indicated polygenically inherited resistance for both species with effective dominance varying as function of the dose applied. Resistance in E. connexa was completely inhibited with piperonyl butoxide (PBO), while the resistance in H. convergens was only partially inhibited with this synergist. High level of esterase activity was found in the resistant population of E. connexa. These results show the first record of resistance for lady beetles in Brazil and the first characterization of inheritance of resistance and metabolism related to insecticide resistance in lady beetles in the world. / Inseticidas e inimigos naturais são empregados nos agroecossistemas dividindo o mesmo objetivo de reduzir populações de pragas. No entanto, raros são os exemplos da ação simultânea com resultados aditivos ou sinergistas de controle. A resistência em joaninhas ao lambda-cialotrina, produto utilizado para o controle de pragas não alvo das joaninhas, pode resultar em uso simultâneo do controle biológico e químico. Assim, neste estudo foi investigada a suscetibilidade de 28 populações brasileiras de oito espécies de joaninhas e duas populações de joaninhas norte americanas ao inseticida lambda-cialotrina, bem como a caracterização dos mecanismos e herança da resistência em espécies com alto grau de tolerância. Entre as populações e espécies estudadas foram determinadas razões de resistência variando de 11- a 38-vezes em quatro populações de Eriopis connexa Germar e de 220-vezes para a população americana de Hippodamia convergens Guérin-Méneville, sendo assim consideradas como selecionadas em campo para resistência ao lambda-cialotrina. Além disso, baseado na DL50 de sete espécies estudadas com ocorrência natural em algodoeiro, 22 e 96% das populações foram mais tolerantes à maior dose recomendada do lambda-cialotrina para uso na cultura do algodão e a DL50 estimada para Anthonomus grandis Boh., respectivamente. A população estudada de E. connexa possui herança da resistência autossomal e incompletamente dominante, enquanto que a resistência knockdown em H. convergens é ligado ao sexo e incompletamente recessiva. Os testes indicaram herança poligênica para E. connexa. Para E. connexa e H. convergens, a dominância efetiva variou em função da dose utilizada. O butóxido de piperonila (PBO) inibiu completamente o metabolismo do lambda-cialotrina em E. connexa, tornando a população resistente similar a população suscetível, enquanto que em H. convergens, o metabolismo foi apenas parcialmente inibido por este sinergista.Vale ressaltar que foi observada alta atividade de esterases na população resistente de E. connexa. Estes resultados compõem o primeiro relato de resistência de joaninhas à inseticida no Brasil e a primeira caracterização da herança e metabolismo quanto à resistência de joaninhas no mundo.

Predicting the net effect of climate change on communities requires understanding how increasing temperatures alter interactions between predators, herbivores, and plants. Over the last several decades, warming experiments have provided important information about how species and their interactions will respond to increasing temperatures. These studies typically examine climate warming by experimentally increasing temperature at a constant level (24 hours) or asynchronously during the daytime, relative to unwarmed control treatments. However, advances in climate models now project that increases in mean global temperatures have been disproportionately driven by increasing nighttime (minimum) temperatures rather than daytime (maximum) temperatures. The timing of warming could have important ecological implications. For example, while night warming could benefit an organism by increasing temperatures towards a more thermally-optimal environment, day warming could raise temperatures beyond a thermal optimum and induce heat-stress. Consequently, mismatching the timing of warming in experiments relative to actual temperature changes could generate misleading predictions about the effects of climate warming. My dissertation has evaluated climate-warming experiments by characterizing past methods, demonstrating present methods, and providing a foundation for future studies. I conducted a meta-analysis on past terrestrial predator-prey climate warming studies that revealed experimental temperatures rarely match model projections, and the magnitude of this mismatch correlated with increased changes in measured effects. Two experiments, one focused on predator functional traits and the other trophic cascades, showed that different types of warming treatments result in different effects of climate change. The context dependency of warming effects necessitates careful consideration of experimental treatments if studies are to accurately predict the effects of climate warming. Region specific climate data are now readily available. Moving forward, ecologists can use these models to inform their warming treatments and perform experiments with the highest level of realism.