No description available.

Offspring phenotype can be adaptively altered via maternal non-genetic inheritance. Such ‘maternal effects’ enable females to adjust their per offspring investment in response to variation in the offspring environment, and thus maximise their reproductive success. Consequently they play a pivotal role in population dynamics and the response of species to environmental change. Despite this, little is known about how maternal effects mediate reproductive investment in response to multiple or novel environmental changes, such as those driven by anthropogenic activity. I use the 2-spot ladybird intraguild predation system, where resources and predation risk are highly variable, to explore the role of maternal effects in the response of a native species to an invasive predator, as well as answering outstanding questions about how maternal effects function under complex and antagonistic sets of variables. The results indicate that it is unlikely that maternally mediated changes in egg phenotype will improve the survival of 2-spot ladybird offspring in the face of predation from larvae of the invasive harlequin ladybird. They do, however, demonstrate the importance of studying maternal effects in the context of the multiple environmental factors, which more accurately represent the complex environments in which organisms live and evolve, corroborating recent theoretical predictions. Finally I provide evidence of the multifaceted nature of parental effects in aposematic species and reveal the role that they may play in shaping the variation in defence and warning coloration observed in adult populations.

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.

Aphidophagous lady beetles rely on multiple sources of food in their environment. Alfalfa fields provide both aphids and many alternate foods, such as other arthropod prey, pollen, and fungi. Alfalfa fields (Medicago sativa L.) in Utah have low aphid densities, which may require lady beetles to consume alternative sources of food. Many methods can be used to determine these diets; frass analysis is used here to compare the diets of the introduced species Coccinella septempunctata L. with two native species, C. transversoguttata richardsoni Brown and Hippodamia convergens Guérin-Méneville, that occur in the Utah alfalfa habitat. In initial laboratory experiments to examine the feasibility of frass analysis, 48 hours at 20oC was sufficient time for adult lady beetles to pass prey cuticle through their guts. When consumed by these adults, pea aphids (Acyrthosiphon pisum [Harris]), alfalfa weevil larvae (Hypera postica [Gyllenhall]), and C. septempunctata larvae produced distinctive fragments in the frass. Such fragments could also be distinguished in frass collected in a field experiment in which aphid densities in plots of alfalfa were manipulated. Furthermore, additional consumed foods could be distinguished in the field experiment, including pollen, fungi, and other types of arthropods. Frass analysis demonstrated higher use of aphid prey by C. septempunctata adults collected from high versus low aphid density plots during the field experiment. Use of other types of prey, such as alfalfa weevil larvae, other arthropods, pollen and fungi, was similar between plots with high and low aphid densities. A field census was performed over two years to track the diets of the three species of lady beetles during the first crop of alfalfa, when two sources of prey in particular were present, aphids and alfalfa weevil larvae. Comparisons of diets revealed that the three species utilized different types of prey to similar degree during both years. In general, however, higher percentages of C. septempunctata adults were found to have consumed aphids and weevils during both years. Also, C. septempunctata was found to produce more frass and consume larger quantities of prey than either native species during the second year.

No description available.

Development of the vertebrate central nervous system is a complex process that relies on the accurate spatiotemporal distribution of signaling centers during embryogenesis. These signals provide cells with positional information, which is integrated via transcription factors and gene regulatory elements to generate a specific downstream gene expression profile that confers specific cellular functions. It is of interest to determine how cells acquire their unique spatiotemporal gene expression patterns. The wide variety of expression profiles established along the dorsoventral axis of the neural tube provides a great system to address this question. Recent advances in zebrafish transgenic technology, along with the phenomenon of a fish-specific genome duplication event, have been exploited here to provide an efficient way of identifying and characterizing gene regulatory elements. An identified neuronal-specific enhancer near the ladybird locus has been incorporated into a transgenic zebrafish strain driving fluorescent reporter protein expression in a subset of dorsal interneurons / Molecular Biology and Genetics

The success of an invasive alien species is often attributed to the ecological advantage gained from natural enemy release. Numerous factors have been suggested as contributing to the success of Harmonia axyridis as an invasive alien species, including enemy release. This thesis studied the interactions of several parasites with H. axyridis, investigating parasite transmission, growth and virulence as well as host immune responses, thereby shedding light on the potential role of enemy release in the invasion biology of this ladybird. Benefits gained by invasive alien species from enemy release diminish if parasites of native species shift hosts to exploit the novel invader. The fungal ectoparasite Hesperomyces virescens began infecting H. axyridis shortly after it invaded the UK, probably as a result of a host shift from Adalia bipunctata. This study found a rapid increase in H. virescens prevalence over three years in London H. axyridis populations. Laboratory study showed H. virescens transmission and growth to be more efficient on A. bipunctata than the novel host. In addition, reciprocal interspecific transfers of H. virescens strains isolated from A. bipunctata and H. axyridis revealed that the infection characteristics of the fungi from these two hosts differed, suggesting strains may have diverged after the initial shift from A. bipunctata to better exploit the host from which they were derived. Laboulbenialian fungi were previously thought to have negligible impacts on host fitness. A detailed examination of H. virescens infecting H. axyridis found distinct virulence, with infections resulting in a 50% reduction in host lifespan. In addition, chronic H. virescens infection in males caused acceleration in the age-associated decline in body condition while for females, infection triggered fecundity senescence and a faster age-related decline in fertility. While their role in accelerating ageing is debated, the results presented here provide evidence that infectious diseases can drive the ageing process in this insect species. In nature, multiple parasites affecting a single host are common. The effect of co-infection on the virulence caused by two fungal infections was characterised using H. axyridis and A. bipunctata hosts. The ability of two ladybird species to defend against an acute fungal parasite, while infected with the relatively avirulent H. virescens was found to be sex-specific. While for females, the presence of co-infection did not alter the virulence seen in singly infected females, a higher mortality rate existed for co-infected males compared with those infected singly. Previously, H. virescens has been considered to be avirulent, however, this study provides evidence that this chronic fungal parasite may be important when considering the mortality associated with co-infections in the field. The invasive success of H. axyridis has, in part, been attributed to a more vigorous immune ability compared with other competitor species. Previously, field studies have shown that the prevalence of the parasitoid wasp Dinocampus coccinellae in H. axyridis is considerably lower than in the UK primary host of this wasp, Coccinella septempunctata. The extent to which the prevalence asymmetry in the field is driven by differences in host encapsulation response was tested by first comparing the encapsulation ability of C. septempunctata and H. axyridis directed against an artificial implant. Following this, the encapsulation response of D. coccinellae parasitized individuals was assessed and compared between the two host species. While encapsulation ability did not differ between the host species, and D. coccinellae did not affect the immune response of H. axyridis, wasp parasitism did alter the encapsulation ability of C. septempunctata, although it was inconsistent across sexes and populations. Overall, this thesis furthers our understanding of the fungal parasite H. virescens and its association with the notorious invader H. axyridis. The research presented here also demonstrates the use of H. axyridis as a model system in areas other than invasion ecology and furthermore, contributes to understanding the role of infectious disease in the rate of ageing. Finally, sex-specific effects were found across the chapters of this thesis, demonstrating the use of H. axyridis in the study of sex-specific effects of infections.

Final publication is available at http://www.plosgenetics.org/article/related/info%3Adoi%2F10.1371%2Fjournal.pgen.1005802 / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19627号 / 医博第4134号 / 新制||医||1016(附属図書館) / 32663 / 京都大学大学院医学研究科医学専攻 / (主査)教授 萩原 正敏, 教授 松田 秀一, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T16:17:54Z No. of bitstreams: 1 Paulo Roberto Ramos Barbosa.pdf: 763274 bytes, checksum: d1db37522ca460481761084d57a5e771 (MD5) / Made available in DSpace on 2016-11-28T16:17:54Z (GMT). No. of bitstreams: 1 Paulo Roberto Ramos Barbosa.pdf: 763274 bytes, checksum: d1db37522ca460481761084d57a5e771 (MD5) Previous issue date: 2012-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The lady beetles are an outstand predatory group among the natural enemies applied as biological control agents against arthropod pests. The lady beetle Tenuisvalvae notata (Mulsant), is a predator of Pseudococcidae and recently was found on cotton plants infested with Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae) and on prickly pear infested with the false red cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae), both in the Semiarid of Pernambuco. Thus, the performance of T. notata preying upon D. opuntiae, F. virgata and eggs of Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) was studied. Further, the predation and reproduction when subjected to different condition of F. virgata availability and scarcity was also investigated. Although naturally collected on colonies of false red cocheneal from prickly pear, T. notata nor developed neither reproduced feeding exclusively on this pest. Likewise, eggs of A. kuehniella did not furnish development and reproduction of T. notata. On the other hand, F. virgata of different stages was successfully used as prey by larvae and adult of T. notata. Adult females of T. notata exhibited a type III functional response preying upon 1st-insar nymph of F. virgata and type II functional response when preying upon 3rd-instar and adults. Based on the functional response it is estimated predation rate of 157.8 1st-instar nymphs, 3.6 3rd-instar nymphs, and 2.2 females of F. virgata per day. Feeding on F. virgata 3rd-instar nymphs resulted in 1.23 eggs produced per each mealybug nymph consumed. However, female lady beetles subjected to prey scarcity exhibited switch on reproductive and survival output already with one day of feeding interval depicting a strong relationship of consumption, reproduction and survivorship between T. notata and F. virgata. The high performance of T. notata preying upon F. virgata and her functional response, in addition the balance of reproduction and survival showed when subjected to prey scarcity, portray T. notata as a feasible predator to control of F. virgata. / Os coccinelídeos predadores se destacam como um dos mais importantes grupos de inimigos naturais empregados no controle biológico de artrópodes pragas. A joaninha Tenuisvalvae notata (Mulsant), espécie nativa da América do sul e predadora de Pseudococcidae, foi recentemente constatada no Semiárido de Pernambuco associada a plantas de algodão infestadas com a cochonilha de listra, Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae), e em palma forrageira infestada com a falsa cochonilha do carmim, Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae). Assim, este trabalho avaliou o desempenho de T. notata sobre D. opuntiae, F. virgata e em ovos de Anagasta kuehniella Zeller (Lepidoptera: Pyralidae), bem como determinou seu potencial de predação e reprodução em diferentes condições de disponibilidade da cochonilha F. virgata. Mesmo sendo coletada em colônias da falsa cochonilha do carmim, T. notata não se desenvolveu e nem reproduziu ao predar exclusivamente esta cochonilha. Da mesma forma, ovos de A. kuehniella não foram adequados como alimento para T. notata. Por outro lado, F. virgata em diferentes estágios de desenvolvimento mostrou-se adequada como presa de T. notata, sendo consumida tanto por larvas quanto por adultos desta joaninha. Fêmeas de T. notata exibiram resposta funcional tipo III predando F. virgata de primeiro instar, e tipo II para ninfas de terceiro instar e fêmeas adultas apresentando um consumo estimado de 157,8 ninfas neonatas, 3,6 ninfas de terceiro instar ou 2,2 fêmeas adultas de F. virgata por dia. A alimentação diária em ninfas de terceiro instar de F. virgata resulta na média de 1,23 ovos produzidos para cada ninfa da cochonilha consumida. No entanto, quando as joaninhas são submetidas a diferentes intervalos de oferta de presa, observa-se influência na produção de ovos e sobrevivência já com um dia de intervalo de alimentação, caracterizando uma estreita relação de consumo, reprodução e sobrevivência para a associação T. notata e F. virgata. O desempenho de T. notata predando F. virgata e sua resposta funcional, somado ao balanço reprodutivo e sobrevivência apresentados sob condição de escassez desta presa, demonstra que T. notata é um predador em potencial para o controle de F. virgata.

This thesis examines American Far Eastern policy from the beginning of the Franklin Roosevelt presidency through the early months of 1938. This study is chiefly concerned with the attack by Japanese aircraft on the USS Panay and its effect on the course of U.S. foreign policy. Particular attention is paid to the Anglo-American dialogue which occurred throughout the Far Eastern Crisis. Prior to the end of 1938, the U.S. administration’s position in Asia was dictated both by policies inherited from preceding administrations and by the extreme isolationism of the American people. This foundation effectively inhibited any cooperation with foreign powers. Relying on a reactive policy in the Far East, Washington remained aloof from entanglement as the President sought a plan which would permit U.S. involvement without inviting isolationist wrath. This paper traces an evolution in American Far Eastern policy, highlighting the Panay incident as a distinctly identifiable turning point whereby isolationism gave way to internationalism.