Typewritten copy Bibliography: leaves 84-87.

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The biology and ecology of an indigenous, non-pest insect on an indigenous host plant were investigated. The study includes a taxonomic description of this new species, an account of its general biology, monitoring of the seasonal fluctuations in numbers of the psyllid and its hymenopterous parasitoids, and a study of various aspects of the host plant, including nitrogen levels, water stress, leaf hardness, and the effect of cutting, in relation to spatial and temporal differences in insect population numbers. Natural enemies, inter- and intra-specific competition had very little determining influence on the population numbers of the psyllid. Temperature and humidity had little direct effect, but may have influenced the population dynamics via its effects on the host plant. Seasonal patterns in psyllid numbers followed fluctuations in nitrogen levels; statistically valid correlations were obtained between leaf nitrogen and psyllid numbers on individual trees at various times. These findings were supported by the results of preliminary laboratory experiments employing different fertilizer treatments. No effect of water stress or leaf hardness was clearly discerned. Cutting of trees altered the characteristics of the subsequent regenerative growth so as to allow massive psyllid infestations to develop, thus showing the tremendous importance of the host plant in determining population levels in this insect. Preliminary investigations of the nature and mechanism of this effect were conducted, and its significance is discussed. The relevance of these findings to modern concepts of regulation in insect populations and to principles of pest management is discussed.

Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Research into the patterns and drivers of insect diversity in the Cape Floristic Region (CFR) lags far behind that of plants. Here I sample insect herbivore communities on a dominant plant family (Restionaceae), and use a spatially nested sampling design and network analysis to evaluate the association between plant and insect diversity in the CFR. I find that plant species richness predicts insect richness better than environmental factors. Turnover in insect communities is strongly associated with turnover in plant (both species and phylogenetic) communities at both local and regional sampling scales, suggesting insect host specificity. Plant communities unsurprisingly show significant turnover at small spatial scales (i.e. communities situated 0.1-3 km apart show significant turnover and may be tied to ecological niches). Insects show a similar pattern, but the decrease in community overlap is more gradual, suggesting many insects can utilise multiple (possibly closely related) hosts while plants are tied to particular niches. The emergent structure of multiple interaction networks is spatially and temporally invariant, despite high compositional change. However, the internal structure of the networks shows variation (i.e. interactions show spatial and temporal turnover). Seasonal interaction turnover is driven by a turnover in herbivores and by herbivore host switching. Spatially the turnover in interactions is driven by simultaneous turnover in both plants and insects, either suggesting that insects are host specific, or that both groups exhibit parallel responses to environmental gradients. Spatial interaction turnover is also driven by a turnover in plants, showing that many insects can utilise multiple (possibly closely related) hosts and have wider distribution ranges than their host plants. Results point toward insect host specificity, but probably not at the species level, as the primary mechanism structuring insect communities associated with the Restionaceae in the CFR. / AFRIKAANSE OPSOMMING: Navorsing wat verband hou met die patrone en meganismes wat insekdiversiteit in the Kaapse Blommeryk (KBR) hou nie pas met dié van plante nie. In hierdie studie neem ek insekmonsters binne een van die dominante plantfamilies (Restionaceae), en gebruik ‘n ruimtelik geneste ontwerp en netwerkanalise om die verbintenis tussen plant- en insekdiversiteit te evalueer. Ek vind plantrykheid voorspel insekrykheid beter as enige omgewingsfaktore. ‘n Omset in in insekgemeenskappe is sterk verbind aan ‘n omset in plantgemeenskappe (beide spesie en filogenetiese) by beide plaaslik en vir die hele streek. Hierdie dui op insekgasheerspesifisiteit. Plantgemeenskappe wys omset teen kort ruimtelike skale (0.1-3 km). Insekte wys ‘n soortgelyke patron, maar die afname in oorvleueling tussen gemeenskappe is meer geredelik. Dit dui dat insek meer as een gasheer kan gebruik, terwyl plante streng tot sekere nisse verbind is. Die ontluikende struktuur van menigde interaksienetwerke wys geen ruimtelike of tydelike variasie nie, ten spyte van hoë gemeenskapsomset. Nietewel, die interne struktuur van die netwerke wys veranderinge (interaksies in netwerke wys omset). Seisonale interaksie-omset kan toegeskryf word aan ‘n omset van herbivore en insekgasheerverandering. Ruimtelike interaksie-omset word toegeskryf aan gelyktydige insek- en plantomset, wat óf deur insekgasheerspesifisiteit veroorsaak word óf deur parallele reaksies tot omgewingsveranderinge. Ruimtelike interaksie-omset word ook deur plantomset beïnvloed, wat aandui sommige insekte kan meer as een gasheer benut en insekte het weier verspreidings as hul gasheer. Resultate dui daarop dat insekgasheerspesifisiteit, maar waarskynlik nie op die spesievlak nie, moontlik die primêre meganisme is wat insekgemeenskappe verbind aan die Restionaceae in die KBR struktureer.

Seven streams, one of them permanent, were studied in western Oregon, USA. The research was designed to assess the value of summer-dry headwaters for conservation oriented landscape management. Streams were categorized primarily according to exposure (forest versus meadow sites) and secondarily according to flow duration (ephemeral = short-flow versus temporary = long-flow sites). Ephemeral streams have discontinuous flow and last less than three months annually. Temporary streams have continuous flow for more than five months each season. Ephemeral forest streams were highly efficient at filtering road-generated sediment. Uptake lengths for suspended sediment were short (36 m-105 m) at moderately elevated input concentrations. As a result of the filtration mechanism, filtration efficiency is expected to increase as annual flow duration decreases. Injection experiments yielded nitrate uptake rates of almost 1% per m of temporary stream channel. Exchange with subsurface flow was the most important route for nitrate removal from the water column. Biological uptake was insignificant in a light-limited forest stream, whereas a considerable amount of nitrate was retained by the biota a nutrient-limited meadow channel. At least 207 insect species were collected from the summer-dry streams. Species richness recorded from temporary forest streams exceeded that in an adjacent permanent headwater and there was high overlap between the fauna of the permanent and the temporary streams. Species richness in ephemeral channels was only 1/4 to 1/3 of that in long-flow forest streams. Multivariate analysis of community structure revealed flow duration and microhabitat pattern (riffle-pool) as the most important environmental factors determining faunal composition in temporary forest streams. Summer drought conditions at the sample sites also were important. By providing habitat and contributing to water quality in permanent downstream reaches, summer-dry streams have the potential to serve multiple purposes in conservation management. Their value from a conservation perspective is unexpectedly high. Landscape management therefore should be directed toward the preservation and protection of ephemeral and temporary streams. / Graduation date: 1993

The objective of this study was to investigate endophagous insect species richness in Fynbos. The influences of plants as determinants of insect occurrence were given special attention. The endophagous insects associated with Proteaceae in Fynbos were compared to endophage assemblages from northern, non-Capensis Proteaceae. The Cape Fynbos genus Protea is utilized by many more insect taxa than the non-Fynbos species. The high diversity of host plants in Fynbos appears to have contributed to generating high, local endophagous insect diversity. Influences of regional climate, biotope and host-plant characteristics on the frequency of occurrence of insect borers exploiting Protea species was investigated in Fynbos. Distinct differences in frequency of encounter of the various insect taxa were recorded for the various host-plants studied. This variability was primarily accounted for by physical host-plant characteristics (infructescence and seed-set variables). These findings have important implications for evolution of insects associated with these plants, as well as for the conservation of insects and in pest control programmes on indigenous cut flowers. The relative species richness of endophagous and ectophagous insects in Fynbos was compared. Gall-forming insects (Diptera: Cecidomyiidae), were found to be considerably more speciose than other feeding guilds, showing that the ratio of endophages to ectophages in sclerophyllous vegetation types is high. The intimate relationship that endophagous insects have with their host plants tends to habitat specialization. These insects are therefore likely to undergo radiation together with their host-plants. Species richness of gall-insects in Fynbos was investigated to establish whether insect richness was proportional to plant species richness. The relationship between gall-insect species richness and plant-species richness was investigated. Fynbos harboured more gall-insect species than other Cape Floristic Region vegetation types. Gall-insect species richness was positively correlated with plant-species richness. Plant species richness appears to have contributed to the evolution of a rich gall-insect fauna in the region. Fynbos gall-insect species richness is comparable to other sclerophyllous vegetation types globally, underscoring the importance of this vegetation type as a centre of galler diversification. Finally, the importance of plant species richness as a determinant of gall-insect species richness was investigated by comparing different sclerophyllous vegetation types under the same climatic conditions. Gall were sampled from Fynbos and Karoo vegetation. Fynbos had higher gall-insect species richness, correlated with plant-species richness. Plant-species richness, or the distal factors that generated it, appear to have contributed significantly to the radiation of gall-insects in this region. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1995.

Extensive seasonal collections along with absolute counts of all the arthropods attracted to medium- and large mammal carcasses resulted in the most complete record of carrion-fauna in Africa to date. The abundance of these species and their seasonal, successional, and diel patterns of carcass-attendance are discussed. More than 98% of species were insects and their presence at the carcass habitat could be classified as obligate, opportunistic, or incidental. A recognisable community of carrion-associated arthropods consistently attracted to the carcass habitat is described, comprising sarcophages, coprophages, keratophages, detritivores, predators and parasites. The interactions and functional ecology of these arthropods is described. The blow-flies Chrysomyia albiceps (Wd.) and C. marginalis (Wd.) were found to be pivotal or key species due to the impact of their larvae on carcass decomposition and their influence on other members of the community. In view of the importance of these blow-flies, their abundance, and the potential role of the adults as dispersal agents of disease organisms, studies were performed to clarify the population dynamics of the two species. The biology and ecology of the immature stages is discussed, including such aspects as the availability of mammal carcasses for oviposition and larval development, and mortality of larvae in the digestive tracts of vultures. By feeding a radioactive isotope of phosphorous (p[32]) to a reared population of adult flies, the dispersal and flight ranges, habitat preferences and population densities of both blow-fly species were studied. The seasonal abundance of C albiceps, C. marginalis, and Lucilia spp. was monitored by monthly trapping at three sites in the study area. Further studies using radioactively-marked blood in a carcass under natural conditions revealed that the distribution of flyspecks deposited by blow-flies is largely dependent upon vegetational structure in the immediate vicinity of the carcass, and the majority of such droplets occurred near the carcass between one and three metres above ground. A distinction in fly-specks was made between vomit droplets, faecal droplets, and the newly tenned discard droplets. The feeding behaviour of C. albiceps and C. marginalis is discussed with reference to the transmission of anthrax in the northern K.N.P. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1984.

Orientador: João Vasconcellos Neto / Tese ( doutorado) - Universidade Estadual de Campinas, Instituto de Biologias / Made available in DSpace on 2018-08-14T07:02:45Z (GMT). No. of bitstreams: 1 Paro_ClaudiaMoreno_D.pdf: 4764996 bytes, checksum: cbd200321d1b685a790530ab2b7f2a91 (MD5) Previous issue date: 2008 / Resumo: A estrutura da comunidade e as dinâmicas populacionais dos serra-paus (Onciderini; Cerambycidae: Coleoptera) foram investigadas na Serra do Japi, Jundiaí-SP, sudeste do Brasil, durante quatro anos, de dezembro de 2002 a dezembro de 2006. Este estudo também verificou o padrão de uso de plantas hospedeiras, incluindo preferências e relações com as características estruturais das plantas. Os adultos ocorreram entre outubro e maio, período utilizado para reprodução. Foi observado um total de 1113 indivíduos, de 12 espécies dos gêneros Oncideres e Psyllotoxus. Dos besouros observados, 1,0% foram classificados como espécies raras (Oncideres miniata, Oncideres bueki e Oneideres macra), 2,6% como espécies dispersas (Oneideres cervina), 37,8% como espécies comuns (Oneideres impluviata, Oncideres ulcerosa, Oneideres dejeani, Psyllotoxus griseocinetus e Oneideres irrorata) e 59,0 % como espécies muito abundantes (Oneideres saga, Oneideres captiosa e Oneideres humeralis). A razão sexual para a maioria das espécies foi de 1: 1 no mês de recrutamento das populações e deslocou a favor das fêmeas nos outros meses. Fatores abióticos, como precipitação e temperatura influenciaram a dinâmica e fenologia dessas populações. Na tribo Onciderini, as fêmeas cortam ramos de árvores, removendo a casca e a madeira com suas mandíbulas. Então colocam seus ovos dentro da madeira ao longo do ramo serrado desprendido, que, quebra e cai ao solo. A larva se desenvolve dentro do ramo morto da sua planta hospedeira. As plantas hospedeiras estão distribuídas em 15 famílias na seguinte ordem de importância: Vochysiaceae 44,6%, Mimosaceae 14,8%, Melastomataceae 11,4%, Lauraceae 9,3% e Anarcadinaceae 5,7%. As outras dez famílias utilizadas representaram 14,1% do total de espécies hospedeiras. Oeideres saga, dejeani, O. impluviata e P. griseocinetus são as espécies de Onciderini mais polífagas. Oneideres irrorata foi à única espécie aparentemente monófaga e especialista. Este trabalho também incluiu parâmetros da biologia e do comportamento destes serra-paus relacionando-os ao uso de cada espécie de planta hospedeira. Os seguintes parâmetros foram medidos: comprimento do ramo serrado, diâmetro, tipo de corte e padrão arquitetura da planta hospedeira e número de incisões para desova. Diferenças nos diâmetros médios dos ramos utilizados por diferentes Oniciderini foram estatisticamente significativas. Oncideres saga serrou os maiores diâmetros de ramos (X = 4,7 ± 0,89), enquanto que O. dejeani apresentou a maior média de incisões para desova (X = 64,9 ± 1,61). Houve relações significativas entre os diâmetros e comprimentos dos ramos cortados com os investimentos reprodutivos médios (n° de ovos/ramo). Estas relações indicam diferentes estratégias reprodutivas, que podem contribuir para reduzir à competição interespecífica e intraespecifica. De modo semelhante, houve também relação positiva entre o 'tamanho médio dos ramos serrados e o tamanho médio das fêmeas de Onciderini, isto apóia a idéia de "parking" na comunidade destes besouros. As estratégias e diferenças no comportamento entre as espécies de serra-paus foram associadas às características das plantas hospedeiras utilizadas, como, por exemplo, defesas físicas e químicas e ainda defesas indiretas por associações inseto-planta. De um modo geral, a diversidade encontrada neste grupo de insetos foi considerada alta, baseada em dados de literatura, mostrando a relevância da Serra do Japi como área a ser preservada. / Abstract: Community structure and dynamics on twig-girdlers populations were investigated from December 2002 to December 2006 in Serra do Japi, Southeaster Brazil. The adults occur between October and May, period utilized mainly for reproduction. It was observed a total of 1113 individuals, grouped in 12 species. From the beetles observed, 1 % was classified as rare species (Oncideres miniata, Oncideres bucki and Oncideres macra), 2,61% as disperse (Oncideres cervina), 37,83% as common (Oncideres impluviata, Oncideres ulcerosa, Oncideres dejeani, Psyllotoxus griseocinetus and Oncideres irrorata) and 59 % as very abundant (Oncideres saga, Oncideres captiosa and Oncideres humeralis). Sex ratio of most ofthe species was of 1: 1 in the recruitment of the populations, and it was deviated towards female in the other months. Abiotic factors, such as precipitation and temperature influenced the dynamics and phenology ofthese populations. In the tribe Onciderini (Coleoptera: Cerambycidae), the female girdles the trees by removing the bark and some of the wood using its mandibles. Then, it digs deep into the wood above the cut and lays its eggs. So, the branch breaks and falls on the ground and the larvae develop on the dead stems of their host plants. This study verified both the patters of host plant used by the insect and the species selection and its relation to structural characteristics of plants in Serra do Japi. 15 families of host plants were found in a whole, and they are listed in decreasing order of the most used ones: Vochysiaceae 44,62%, Mimosaceae 14,78%, Melastomataceae 11 ,41 %, Lauraceae 9,35% and Anarcadinaces 5,71 %, the other species summed 14,13% ofthe studied species. O. saga, O. dejeani, O. impluviata and P. griseocinetus were the most poliphagous species. O. irrorata was the only monophagous and specialist specie. Some other aspects like: 1) bioecological parameters of twig girdlers while using each host plant; 2) girdled stem len7 3) stem diameter; 4) cut type of the branch and 5) architectural pattern of the host plant w1 also included in this study. The differences of the diameter average were statistically significant. It was observed that O. saga cut branches of larger diameter ( X = 4,77 ± 0,89 DP). The average number of posture incisions by O. dejeani (X = 64,94 ±1,61 DP) was greater than the other species. There was significative relation between the average diameter and the twig length of the host plants with the reproductive investment (number of eggs/twig) of the twig-girdlers species from Serra do Japi. These relations indicate different reproductive strategies which contribute for reducing inter-specific competition. Likewise, the positive relation between the average size of the twig and the female size of the specie Onciderini indicates organizational standards of their community. The strategies and different behavior among the twig-girdler species were associated with characteristics of the used host plants. For instance: not only physical and chemical defenses but also indirect defenses by insect-plant associations. The diversity of this group of insects found in Serra do Japi was considered high. This, was based on a literature review, and thus shows that the place is environmentally and ecologically balanced in richness of species. Therefore, it is necessary that the site be preserved. / Doutorado / Doutor em Ecologia