Pollination data is provided for a third of the Plectranthus species in southern Africa. In the largest genus of Lamiaceae in the region (53 species), 18 were studied, plus two species of allied genera (Pycnostachys urticifolia and Aeollanthus parvifolius). Study of these 20 species aimed to describe the groups of pollinators that have driven pollinator specialisation. Case histories are provided upon which future studies of Lamiaceae pollination, breeding systems and speciation may be based. Bees (Apidae) and flies (Nemestrinidae, Acroceridae and Tabanidae) are the main pollinating insect groups. Seven straight-tubed Plectranthus species show a match between corolla tube- and proboscis length of nectar-feeding pollinators. Long-proboscid nemestrinid flies are specialised on long-tubed Plectranthus species (P. ambiguus, P. hilliardiae, P. reflexus and P. saccatus), while shorter-proboscid flies of all three families are important pollinators of straight-tubed species with medium- and short corolla tubes. Seven species with sigmoid corolla tubes are bee-pollinated, with fly-pollination prevalent in some. Bent corolla tubes, coupled with length, act as barriers to illegitimate nectarfeeders and ensures alignment of pollinators for effective pollen placement and carryover. It is suggested that straight-tubed species may have evolved from sigmoid-tubed species. Long-tubed species with straight corollas in other Lamiaceae may show convergent pollination by long-proboscid flies, with the guild being dependent on habitat and distribution of plants and flies. Formal establishment of the Stenobasipteron wiedemanni pollination guild extends the study from Plectranthus to selected Acanthaceae, Orchidaceae, Balsaminaceae, Gesneriaceae and Iridaceae, occurring in forested habitat along the Eastern seaboard. Micro-distillation of essential oils confirmed parentage of a putative natural hybrid; once established, hybrid data allows studies of the importance of natural hybridisation events in explaining pollinator fidelity. Nectar sugar studies in Plectranthus mostly showed sucrose dominance; cases of hexose dominance are noted and discussed. Nectar volume and concentration proved variable and do not fit any trends. Pollination by medium-proboscid acrocerid flies has importance for ‘medium-tubed’ plants, since six of the Plectranthus species are solely or partially reliant on Acroceridae for pollination. An appendix with consolidated data describes the 20 study species i.t.o. morphology, habitat, study sites, field work, pollinator observations and insect vouchers. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2005. / Title from second page of PDF document. Includes bibliographical references.

Orientador: Vera Nisaka Solferini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T04:40:21Z (GMT). No. of bitstreams: 1 Abreu_AluanaGoncalvesde_D.pdf: 3682927 bytes, checksum: e8b0e5d165148e225082c7057c66bb6e (MD5) Previous issue date: 2009 / Resumo: Tomoplagia reticulata (Diptera: Tephritidae) é um fitófago especialista em Eremanthus glomerulatus (Asteraceae). Os adultos ovipõem nas inflorescências da planta hospedeira, onde as larvas se desenvolvem. O histórico de coletas de T. reticulata mostra uma grande variação na quantidade de insetos infestando cada indivíduo de E. glomerulatus. A fim de verificar se a variação no número de herbívoros nas populações do hospedeiro é associada a alguma característica química e/ou genética deste, comparamos as variabilidades genética e química entre indivíduos de E. glomerulatus com diferentes níveis de infestação por T. reticulata (cap. 1). Eremanthus glomerulatus tem baixa variabilidade genética, provavelmente associada à distribuição restrita desta espécie. Apesar da distribuição fragmentada, há pouca estruturação entre as populações desta planta, explicada pelo maior fluxo gênico entre ambientes fragmentados em espécies anemocóricas. As características genéticas e químicas de E. glomerulatus não explicam a variação no nível de herbivoria das populações do hospedeiro. No capítulo 2, testamos a hipótese de que fitófagos especialistas apresentam maior diferenciação genética e menor diversidade do que generalistas, comparando o nível de variabilidade e estrutura genética de T. reticulata com o de outros fitófagos com diferentes amplitudes de hospedeiro. As populações de T. reticulata apresentaram baixa variabilidade e grande estruturação genética, o que é associado à distribuição fragmentada da planta hospedeira, que restringe a distribuição das pequenas populações do inseto. No capítulo 3, caracterizamos a composição genética das populações de Tomoplagia reticulata e de T. pallens, uma espécie irmã. Ambas as espécies parasitam E. glomerulatus; T. reticulata ocorre em MG e T. pallens em GO. Há uma zona de contato entre as espécies no Sul de MG, onde elas hibridizam. Ocasionalmente T. pallens chega ao centro de MG (Santana do Riacho), região mais fria. Esta migração provavelmente está associada a anos excepcionalmente quentes. / Abstract: Tomoplagia reticulata (Diptera: Tephritidae) is a phytophagous insect which is specialist on Eremanthus glomerulatus (Asteraceae). Adults oviposit in flower heads, where larvae develop. Sampling records for T. reticulata show that there is great variation in the number of insects parasitizing each plant. To verify if this variation is associated with chemical or genetic characteristics of the host plant, we assayed E. glomerulatus' genetic and chemical variability and compared between individuals with different levels of infestation by T. reticulata (chapter 1). Eremanthus glomerulatus has low genetic variability, probably related to its narrow geographic distribution. There is low genetic structure among populations despite its fragmented distribution, due to enhance gene flow in fragmented habitats in anemocoric species. E. glomerulatus' chemical and genetic characteristics don't explain variation in herbivory. In chapter 2, we tested the hypothesis that herbivorous insect species with narrow diet breadth are expected to be more prone to genetic differentiation and lower genetic diversity than insect species with a wider diet breadth, comparing T. reticulata's genetic variability and structure with other phytophagous with different host ranges. Tomoplagia reticulata has low genetic variability and great genetic structure, which is associated with its host fragmented distribution that restricts the distribution of insect populations. In chapter 3, we described genetic composition of Tomoplagia reticulata and T. pallens, a sister species. Both of them parasitize E. glomerulatus; T. reticulata occurs in MG and T. pallens in GO. There is a contact zone between them in southern MG, where they hybridize. Occasionally, T. pallens arrives in the center of MG (Santana do Riacho), a colder region. This migration is probably associated with extremely hot years. / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular

Orientadores: Maria Ligia Rodrigues Macedo, Goran Nesic / Dissertação (Mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:49:38Z (GMT). No. of bitstreams: 1 Silva_DesireeSoaresda_M.pdf: 1615013 bytes, checksum: e404c15f23a6cd6027750ac4c6e28c69 (MD5) Previous issue date: 2010 / Resumo: As sementes são ricas fontes de inibidores de proteinases, que prejudicam sua qualidade nutricional, reduzindo a digestibilidade das proteínas e sua absorção. Neste estudo, um inibidor de tripsina (ApTI) foi purificado a partir de sementes de Adenanthera pavonina e testado seu efeito no crescimento e desenvolvimento de dois lepidópteros. Larvas de Anagasta kuehniella alimentadas com ApTI 1% mostraram redução de 50% na sobrevivência e no peso médio. Larvas de Anticarsia gemmatalis alimentadas com dieta contendo ApTI 0,5% apresentaram diminuição de 31% na sobrevivência e de 22% no peso médio. O tempo de desenvolvimento larval e pupal de Anagasta kuehniella alimentadas com a dieta contendo ApTI 1% foi maior, enquanto a porcentagem de adultos sobreviventes diminuiu em relação ao grupo controle. A avaliação nutricional de ApTI sobre o desenvolvimento larval de A. kuehniella mostrou redução na eficiência de conversão do alimento ingerido (ECI) e alimento digerido (ECD), e aumento na digestibilidade aproximada (AD) e no custo metabólico (CM). Em relação as larvas de A. gemmatalis, não houve efeito na (ECI), porém foi observado redução na (ECD) e aumento na (AD) e no (CM). Para examinar o efeito in vivo de ApTI sobre os insetos, as atividades das proteinases intestinais das larvas que se alimentaram com dietas livres do inibidor e contendo o inibidor a 0,25 - 1% foram comparadas através de ensaios enzimáticos e eletroforese em gel de atividade enzimática. Larvas de quarto instar de A. kuehniella alimentadas com dieta contendo ApTI 1% apresentaram diminuição na atividade tríptica do intestino e manutenção dessa nas fezes. Larvas de A. gemmatalis alimentadas em dieta contendo ApTI 0,5% mostraram diminuição da atividade tríptica do intestino e das fezes. Estes resultados sugerem que ApTI possui efeitos anti-metabólicos quando ingeridos por A. kuehniella e A.gemmatalis. / Abstract: Seeds are a major source of proteinases inhibitors, which cause nutrition quality damage and reduce the absorption and digestibility of proteins. In this study, a trypsin inhibitor (ApTI) was purified from Adenanthera pavonina seeds and their effect on growth and development tested in two Lepidoptera. Anagasta kuehniella larvae were fed with ApTI 1% showing a significant decrease in survival and larval weight (50%). A. gemmatalis fed with 0.5% ApTI showed a survival of 31% and decrease in weight of 22%, when compared with the control group. Larval and pupal developmental time of Anagasta kuehniella larvae, fed on an ApTI diet at 1% was significantly longer, and the percentage of surviving adults decreased. The nutritional effect of ApTI on A. kuehniella larval development was to decrease the conversion of ingested food (ECI) and digested food (ECD) efficiency, and increase estimated digestibility (AD) and metabolic cost (CM). ApTI had no effect on A. gemmatalis conversion of ingested food efficiency. However, a decrease in the conversion of digested food efficiency (ECD) and increase in estimated digestibility (AD) and metabolic cost (CM) were observed. Enzymatic assays and electrophoreses were performed in order to evaluate the in vivo ApTI effect of larval intestinal proteinase activities between those that were not fed with the inhibitor and those fed with inhibitor (0.25 - 1%). A. kuehniella four instars larvae fed with 1% ApTI showed a reduction in intestinal tryptic activity and maintenance of feces tryptic activity. A. gemmatalis fed with 0.5% ApTI suffered a reduction in intestinal and feces tryptic activities. These results suggest that ApTI presents considerable anti-metabolic effects in A. kuehniella and A. gemmatalis. / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular

The chemical defences of insects against predators are either passive or aggressive. Passive defence is achieved through crypsis, and aggressive defence is maintained by a conspicuous or 'aposematic' (Poulton, 1890) appearance that advertises some noxious quality of the insect harmful to a predator. Aposematism is mutually beneficial to both the bearer and its predator, whereas crypsis only benefits the prey species. It is therefore not surprising that the fascinating array of chemical defences in insects is both diverse and widespread (Roth and Eisner, 1962). Intro. p. 1.

Orientador: Thomas Michael Lewinsohn / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T17:54:45Z (GMT). No. of bitstreams: 1 AlmeidaNeto_Mario_D.pdf: 4855549 bytes, checksum: 4daf7795fa92679c987ea39ce90c2f73 (MD5) Previous issue date: 2006 / Resumo: Examinei os efeitos da degradação antrópica sobre diferentes aspectos da diversidade de espécies e interações entre plantas da família Asteraceae e os insetos herbívoros cujas larvas se alimentam no interior de seus capítulos. Toda a amostragem de campo foi realizada em vinte áreas de cerrado com diferentes níveis de degradação antrópica em três municípios vizinhos do estado de São Paulo. A densidade de gramíneas invasoras foi usada como medida indireta do nível de degradação antrópica das áreas. A riqueza de Asteraceae apresentou uma relação quadrática com a degradação, com um pico em níveis intermediários. A proporção de espécies típicas de cerrado diminuiu em áreas mais degradadas, mas a representatividade dos diferentes grupos taxonômicos não apresentou nenhuma variação consistente. Como esperado, a riqueza de plantas hospedeiras foi o principal preditor do número de herbívoros nas áreas. Conseqüentemente, a riqueza de herbívoros também apresentou uma relação quadrática com a degradação, mas pico marginalmente significativo em níveis intermediários. Quando o efeito da riqueza de hospedeiras é descontado através de uma regressão múltipla, o efeito final da degradação sobre a riqueza de herbívoros passa a ser negativo. Portanto, a relação quadrática entre degradação e riqueza de herbívoros é um efeito indireto via plantas hospedeiras. O número de interações distintas entre herbívoros e plantas também apresentou uma relação quadrática com a degradação. Visto que a conectância das redes de interações tende a diminuir com o aumento da riqueza, as áreas com níveis intermediários de degradação apresentaram valores de conectância menores que as áreas menos e mais degradadas. Quando a influência da riqueza de espécies é controlada através de uma análise alométrica, os valores de conectância mostraram uma queda em áreas onde a degradação é maior. O grau de anillhamento de interações planta-herbívoro também diminuiu significativamente nas áreas mais degradadas, enquanto que a degradação parece não afetar de forma consistente o grau de compartimentação das interações. Por fim, a degradação influenciou a resistência das redes de interações a extinções secundárias, mas seus efeitos não foram uniformes ao longo do gradiente de degradação / Abstract: This study aimed to investigate the effects of anthropogenic disturbance on the diversity and structure of interactions between species of Asteraceae and the endophagous insects whose larvae feed inside their flower heads. Field sampling was performed in 20 remnants of cerrado vegetation in three adjacent counties in the state of São Paulo, Southeastem Brazil. The density of invasive grass cover was used as surrogate of anthropogenic disturbance leveI. Asteraceae richness showed a quadratic ;elationship with disturbance and peaked at intermediate disturbance levels. The proportion of typical Asteraceae from cerrado decreased in more disturbed sites, but the taxonomic distinctness of Asteraceae did not change consistently along the disturbance gradient. As expect, host plant richness was the major predictor ofherbivore richness. Consequently, the richness of endophages also showed a quadratic variation along the disturbance gradient. However, when the effect of host plant richness on endophages is added into a multiple linear regression, the final direct effect of disturbance on insect richness is negative. Thus, the quadratic relationship between disturbance and endophage richness is explained through an indirect effect via host plant richness. The number of interactions between endophages and plants was also quadratical1y related to disturbance. Since connectance as a rule is negatively related to species number, those sites with intermediate disturbance levels presented lower connectance values than sites at the extremes of the gradient. Afier controlling for the influence of species richness on connectance values, this network property decreased at higher disturbance levels. The degree of nestedness of recorded plant-herbivore interactions was ais o lower in more disturbed sites. In contrast, disturbance leveI had no consistent effect on the leveI of compartmentation of the interactions. Finally, anthropogenic disturbance affected the fragility ofthe plant-herbivore intera~tion networks to secondary extinctions, but their effects were not uniform along the disturbance gradient / Doutorado / Ecologia / Doutor em Ecologia

Master of Science

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003. / Thesis documentation sheet inserted. Includes appendix of four papers and manuscripts, two co-authored with Barbara Ekbom. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.

No description available.

Thesis (PhD)--Macquarie University, Division of Environmental and Life Sciences, Dept. of Biological Sciences, 2005. / Bibliography: p. 178-203. / Introduction -- Study sites -- Leaf characteristics and resource availability -- Insect herbivory and resource availability -- Insect communities and resource availability -- Influence of resource availability on recovery from herbivory -- Conclusions. / This project used the resource availability hypothesis (Coley et al., 1985) as a framework for investigating the relationship between resource availability (as defined by soil nutrients), leaf traits, insect herbivore damage and insect community structure. According to the hypothesis, plants from low resource environments should be better-defended, have longer leaf lifespans and slower growth rates than plants from higher resource environments. Higher resource plant species are expected to suffer higher levels of herbivory and recover faster from herbivory than low resource plant species (Coley et al. 1985). A corollary to this hypothesis is that plants from higher resource sites should support greater densities of insect herbivores than low resource species. Comparisons between high and low resource sites were made in terms of: (i) leaf traits of mature and immature leaves; (ii) phenology of leaf maturation; (iii) herbivore damage in the field and laboratory; (iv) diversity and abundance of herbivorous insect fauna; and (v) ability to recover from herbivory. / Mode of access: World Wide Web. / 243 p. ill., maps