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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.
161

Assessment of plants used for the treatment of cattle wounds and myiasis in Amatola Basin, Eastern Cape Province, South Africa

Soyelu, Oluseyi Temitope January 2010 (has links)
No description available.
162

Distribuição temporal e espacial de danos de grandes lagartas em pomar de macieira / Temporal and spatial distribution damage of "big caterpillars" in apple orchard

Nunes, Janete Cardoso 29 August 2011 (has links)
Made available in DSpace on 2016-12-08T16:44:39Z (GMT). No. of bitstreams: 1 PGPV11MA077.pdf: 8728650 bytes, checksum: 67de9ee79430f3f94f1b5c3369535d74 (MD5) Previous issue date: 2011-08-29 / Apple orchards in southern Brazil are attacked by a great diversity of organisms throughout the crop cycle and special attention should be given to insect pests. The damage caused by "big caterpillars" has caused concern in the productive sector, and research on alternative methods of control for these insects is still incipient. The study was conducted at the Estação Experimental de Fruticultura de Clima Temperado (EFCT) da Embrapa Uva e Vinho, em Vacaria-RS. Its objective was to identify the species of Lepidoptera occurring in apple orchards; establish and determine the floating population indices during the crop; check harm reduction "big caterpillars" to obtain the spatial distribution of damage in apple orchards and study the effect of different diets on the development of natural Physocleora dimidiaria (Guenée, 1852) (Geometridae), a species belonging to the group of "big caterpillars." Light traps were installed three of the adapted model "Luiz de Queiroz", October 2010 and March 2011, Fuji orchard. The removal of insects occurred twice a week, the collected material was stored in labeled plastic bags and taken to the laboratory for screening. The moths were identified by comparison, based on specimens in the entomological collection of existing EFCT and the unidentified specimens were sent to specialists. We determined the species richness, diversity indexes, constancy and dominance. We evaluated the incidence and spatial distribution of damage "big caterpillars" in the periods of fruit thinning, pre-harvest and harvest. We calculated the mean (x), variance (s2) for each occasion of sampling and dispersion indexes I, Morisita, negative binomial and Poisson. We recorded 40 species belonging to the families of Lepidoptera: Arctiidae, Geometridae and Noctuidae. Damage to the "big caterpillars" presented dispersion pattern defined by aggregation in the thinning and pre-harvest and regular harvesting. The light traps can be used to survey and monitor species diversity, however, were not effective to control the damage of "big caterpillars" in apple orchard. Was evaluated in the laboratory the effect of different diets on the natural development of P. dimidiaria. Seventy larvae were observed until the F1 generation in BOD incubator at each natural diet: Trifolium repens L. (white clover), Rumex obtusifolius (tonguein- cow), Malus domestica (apple leaves) fruit and apple cultivar Gala. Data in the table of life and fertility obtained for P. dimidiaria indicate that a generation time was 49.09 days in T. repens; of 60.04 days (apple leaves) and 50.17 days in R. obtusifolius. The net reproductive rate was higher in caterpillars fed on R. obtusifolius times corresponding to 183.60, with each generation / Pomares de macieira do Sul do Brasil são atacados por uma grande diversidade de organismos ao longo do ciclo da cultura e atenção especial deve ser dada aos insetos-praga. Os danos causados por grandes lagartas vêm causando preocupação no setor produtivo, e a pesquisa com métodos alternativos de controle para tais insetos ainda é incipiente. O estudo foi realizado na Estação Experimental de Fruticultura de Clima Temperado (EFCT) da Embrapa Uva e Vinho, em Vacaria-RS. Teve por objetivos identificar as espécies de lepidópteros ocorrentes em pomar de macieira; estabelecer a flutuação e determinar índices populacionais ao longo da safra; verificar a redução de danos de grandes lagartas ; obter a distribuição espacial do dano em pomar de macieira e estudar o efeito de diferentes dietas naturais sobre o desenvolvimento de Physocleora dimidiaria (Guenée, 1852) (Geometridae), uma espécie pertencente ao grupo das grandes lagartas . Foram instaladas três armadilhas luminosas adaptadas do modelo Luiz de Queiroz , de outubro de 2010 e março de 2011, em pomar da cultivar Fuji. A retirada dos insetos ocorreu duas vezes por semana, o material coletado foi armazenado em sacos plásticos etiquetados e levado até o laboratório para triagem. As mariposas foram identificadas por comparação, com base em exemplares existentes na coleção entomológica da EFCT. Os exemplares não identificados foram enviados a especialistas. Foi determinada a riqueza de espécies, os índices de diversidade, constância e dominância. Avaliou-se a incidência e a distribuição espacial do dano de grandes lagartas em frutos nos períodos de raleio, pré-colheita e colheita. Calculou-se a média (x), a variância (s2) para cada ocasião de amostragem e os índices de dispersão I, Morisita, binomial negativa e Poisson. Foram registradas 40 espécies de lepidópteros pertencentes às famílias: Arctiidae, Geometridae e Noctuidae. Os danos de grandes lagartas apresentaram padrão de dispersão definido pela agregação no raleio e pré-colheita e regular na colheita. As armadilhas luminosas podem ser utilizadas para levantamento de diversidade de espécies e monitoramento, porém, não foram eficientes para controlar os danos de grandes lagartas em pomar de macieira. Foi avaliado em laboratório o efeito de diferentes dietas naturais sobre o desenvolvimento de P. dimidiaria. Setenta lagartas foram acompanhadas até a geração F1 em estufa incubadora BOD, em cada dieta natural: Trifolium repens L. (trevo-branco), Rumex obtusifolius (língua-de-vaca), folhas de Malus domestica (macieira) e frutos de macieira cultivar gala. Os dados da tabela de vida e de fertilidade obtidos para a P. dimidiaria indicaram que o tempo de uma geração foi de 49,09 dias em T. repens; de 60,04 dias (folhas de macieira) e de 50,17 dias em R. obtusifolius. A taxa líquida de reprodução foi maior em lagartas alimentadas com R. obtusifolius correspondendo a 183,60 vezes, a cada geração
163

Purifica??o, caracteriza??o e an?lise da atividade bioinseticida, de um inibidor de tripsina em sementes de catanduva (Piptadenia moniliformis)

Cruz, Ana Celly Bezerra 20 October 2008 (has links)
Made available in DSpace on 2014-12-17T14:03:30Z (GMT). No. of bitstreams: 1 AnaCBC.pdf: 1320381 bytes, checksum: 881b82ecb0df2b87414957a1e02761bb (MD5) Previous issue date: 2008-10-20 / One Kunitz-type trypsin inhibitors (PmTI) was purified from Piptadenia moniliformis seeds, a tree of the sub-family Mimosoideae, by TCA precipitation, affinity chromatography on immobilized trypsin-Sepharose, DEAE cellulose (ion exchange) and Superose 12 (molecular exclusion) column FPLC/AKTA. The inhibitor has Mr of 25 kDa by SDS-PAGE and chromatography molecular exclusion. The N-terminal sequence of this inhibitor showed high homology with other family Kunitz inhibitors. This also stable variations in temperature and pH and showed a small decrease in its activity when incubated with DDT in the concentration of 100mM for 120 minutes. The inhibition of trypsin by PmTI was competitive, with Ki of 1.57 x10-11 M. The activity of trypsin was effectively inhibited by percentage of inhibition of 100%, among enzymes tested, was not detected inhibition for the bromelain, was weak inhibitor of pancreatic elastase (3.17% of inhibition) and inhibited by 76.42% elastase of neutrophils, and inhibited in a moderate, chymotrypsin and papain with percentage of inhibition of 42.96% and 23.10% respectively. In vitro assays against digestive proteinases from Lepidoptera, Diptera and Coleoptera pests were carried out. Several degrees of inhibition were found. For Anthonomus grandis and Ceratitis capitata the inhibition was 89.93% and 70.52%, respectively, and the enzymes of Zabrotes subfasciatus and Callosobruchus maculatus were inhibited by 5.96% and 9.41%, respectively, and the enzymes of Plodia. interpunctella and Castnia licus were inhibited by 59.94% and 23.67, respectively. In vivo assays, was observed reduction in the development of larvae in 4rd instar of C. capitata, when PmTI was added to the artificial diet, getting WD50 and LD50 of 0.30% and 0.33%, respectively. These results suggest that this inhibitor could be a strong candidate to plant management programs cross transgenic / Um inibidor de tripsina da fam?lia Kunitz (PmTI) foi purificado de sementes de Piptadenia moniliformis, uma ?rvore da sub-fam?lia Mimosoideae, atrav?s da precipita??o com ?cido tricloroac?tico (TCA), cromatografia de afinidade com tripsina acoplada em sepharose, coluna DEAE- celulose(troca i?nica) e Superose 12 (exclus?o molecular) em sistema FPLC/AKTA. O inibidor possui massa molecular de 25 kDa como confirmado atrav?s de SDS-PAGE e cromatografia de exclus?o molecular. A seq??ncia do N-terminal deste inibidor mostrou alta homologia com outros inibidores da fam?lia Kunitz. Este tamb?m ? est?vel as varia??es de temperatura e pH, e apresentou um pequeno decr?scimo na sua atividade quando incubado com DTT na concentra??o de 100 mM por 120 minutos. A inibi??o da tripsina foi do tipo competitiva com Ki de 1,57x10-11 mM. A atividade da tripsina foi inibida efetivamente com percentual de inibi??o de 100%, entre as outras enzimas testadas n?o foi detectada inibi??o para a bromela?na, foi fracamente inibidor da elastase pancre?tica (3,17% de inibi??o), inibiu em 76,42% elastase de neutr?filos, inibiu de forma moderada quimotripsina e papa?na com percentual de inibi??o de 42,96% e 23,10%, respectivamente. Ensaios in vitro foram realizados com as proteinases digestivas de Lepid?ptera, Cole?ptera e D?ptera. V?rios graus de inibi??o foram encontrados. Para Anthonomus grandis e Ceratitis capitata a inibi??o foi de 89,93% e 70,52%, respectivamente, e as enzimas de Zabrotes subfasciatus e Callosobruchus maculatus foram inibidas com percentuais de 5,96% e 9,41% respectivamente, e as enzimas de Plodia interpunctella e Castnia licus foram inibidas com percentuais de 59,94% e 23,67%, respectivamente. No ensaio in vivo, foi observada redu??o no desenvolvimento de larvas em 4? ?nstar de C. capitata, quando PmTI foi adicionado ? dieta artificial, obtendo WD50 de 0,30% e LD50 0,33% . Estes resultados sugerem que este inibidor possa ser um forte candidato para programas de melhoramentos de plantas via transgenia
164

Toxicidade de extratos vegetais ao percevejo bronzeado do eucalipto Thaumastocoris peregrinus (hemiptera: heteroptera: thaumastocoridae) e organismos não-alvo / Toxicity of plant extracts to the bronze bug Thaumastocoris peregrinus (Hemiptera: Heteroptera: Thaumastocoridae) and non-target organisms

Haas, Jucelaine 27 November 2015 (has links)
CAPES; CNPq / Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) é um inseto originário da Austrália que está causando sérios danos à cultura do eucalipto ao redor do mundo. Ao alimentar-se da seiva das folhas, causa seu bronzeamento, podendo levar à desfolha. Medidas de controle estão sendo estudadas e a mais promissora é o parasitoide de ovos Cleruchoides noackae (Hymenoptera: Mymaridae). Produtos alternativos a base de compostos provenientes de plantas com potencial inseticida também poderiam ser uma ferramenta importante, e talvez serem utilizados concomitantemente com o parasitoide, visando um controle mais efetivo. Desta forma, o objetivo deste trabalho foi verificar a ação dos extratos aquosos de Matricaria chamomilla, Echinodorus grandiflorus, Punica granatum, Maytenus ilicifolia e Origanum majorana a 5% sobre T. peregrinus. Além disso, estudar sua possível toxicidade contra C. noackae e Gallus domesticus L., tendo em vista que estes compostos podem ter efeito negativo indesejado sobre organismos não alvo. Em uma primeira etapa, cromatografia líquida de alta eficiência (HPLC) foi utilizada para verificar os compostos fenólicos presentes nos extratos. Os extratos, então, foram testados sobre percevejo adultos, em confinamento (para verificar a ação inseticida) e teste de livre escolha (para verificar a ação repelente). Os três extratos que mostraram melhores resultados foram selecionados para os testes com os organismos não alvo. Com relação à C. noackae, testes pré e pós-parasitismo, de confinamento e de livre-escolha foram realizados para verificar se os extratos afetariam a escolha do hospedeiro pelas fêmeas ou o desenvolvimento das fases imaturas do parasitoide. Para verificar se os extratos seriam tóxicos a G. domesticus, estes foram adicionados à dieta de aves juvenis por cinco dias. Parâmetros como peso, consumo de alimento, quantificação de enzimas séricas e análise histopatológica foram realizados. Por meio das análises cromatográficas, foram detectados os ácidos gálico, ferúlico, cafeico, cumárico e vanílico. Os extratos levaram à mortalidade de 100% dos insetos em até 49% do tempo, quando comparados com a testemunha, mas E. grandiflorus, Matricaria chamomilla e Maytenus ilicifolia destacaram-se mostrando efeito repelente, sendo selecionados para a próxima etapa. Nenhum destes afetou a escolha do hospedeiro pela fêmea ou a emergência dos parasitoides, quando comparado com a testemunha. Além disso, os extratos não causaram alterações em G. domesticus, em nenhum dos parâmetros avaliados. Desta forma, verificou-se que E. grandiflorus, Matricaria chamomilla e Maytenus ilicifolia têm potencial para serem utilizados no controle de T. peregrinus, bem como mostraram-se seguros para C. noackae e G. domesticus. / Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae ) is an insect from Australia which is causing severe damage to eucalyptus crops around the world. When feeding from the leaves sap, it causes bronzening, and in extreme cases, may lead to the tree death. Control methods have been studied and the most promising so far is the egg parasitoid Cleruchoides noackae (Hymenoptera: Mymaridae). Alternative products from plants with insecticidal properties could also be a viable option, and they might even be used concomitantly with C. noackae, aiming for a most effective control, but still safe for the environment. Thus, the objective of this work was to verify the action of 5% aqueous plant extracts of Matricaria chamomilla, Echinodorus grandiflorus, Punica granatum, Maytenus ilicifolia a n d Origanum majorana on T. peregrinus. In addition, we aimed to study the extracts potential toxicity to C. noackae and Gallus domesticus L., since the plant compounds might have negative effect upon the non-target organisms. At first, HPLC (High Performance Liquid Chromatography) was used to verify which phenolic compounds would be found in the plant extracts. These were tested on bronze bug adults, in confinement test (to verify the insecticidal action of the extracts) and free-choice test (to verify the repellency). The extracts that showed better results were selected for further tests with non-target organisms. Regarding C. noackae, pre-parasitism and post-parasitism, confinement and free-choice tests were performed to verify if the extracts would affect the host-choosing by the female or the development of the immature stages of the parasitoid. To verify if the extracts would be toxic to G. domesticus, the plant extracts were added to young birds feed for five days. Parameters such as weight gain, food intake, quantification of serum enzymes and histopathological analysis were carried out. HPLC analysis detected gallic, ferulic, vanillic, caffeic and cumaric acid in the extracts samples. All plant extracts tested reduced T. peregrinus survival, but E. grandiflorus, Matricaria chamomilla Maytenus ilicifolia had also a repellent effect, and were tested on the non-target organisms. None of these extracts affected neither the host choice by C. noackae nor adult emergency, when compared to the control group. In addition, the extracts did not cause alterations in any of the studied parameters. Thus, we verified that E. grandiflorus, Matricaria chamomilla and Maytenus ilicifolia have potential to be used to control T. peregrinus and are safe to C. noackae and G. domesticus.
165

Toxicidade de extratos vegetais ao percevejo bronzeado do eucalipto Thaumastocoris peregrinus (hemiptera: heteroptera: thaumastocoridae) e organismos não-alvo / Toxicity of plant extracts to the bronze bug Thaumastocoris peregrinus (Hemiptera: Heteroptera: Thaumastocoridae) and non-target organisms

Haas, Jucelaine 27 November 2015 (has links)
CAPES; CNPq / Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) é um inseto originário da Austrália que está causando sérios danos à cultura do eucalipto ao redor do mundo. Ao alimentar-se da seiva das folhas, causa seu bronzeamento, podendo levar à desfolha. Medidas de controle estão sendo estudadas e a mais promissora é o parasitoide de ovos Cleruchoides noackae (Hymenoptera: Mymaridae). Produtos alternativos a base de compostos provenientes de plantas com potencial inseticida também poderiam ser uma ferramenta importante, e talvez serem utilizados concomitantemente com o parasitoide, visando um controle mais efetivo. Desta forma, o objetivo deste trabalho foi verificar a ação dos extratos aquosos de Matricaria chamomilla, Echinodorus grandiflorus, Punica granatum, Maytenus ilicifolia e Origanum majorana a 5% sobre T. peregrinus. Além disso, estudar sua possível toxicidade contra C. noackae e Gallus domesticus L., tendo em vista que estes compostos podem ter efeito negativo indesejado sobre organismos não alvo. Em uma primeira etapa, cromatografia líquida de alta eficiência (HPLC) foi utilizada para verificar os compostos fenólicos presentes nos extratos. Os extratos, então, foram testados sobre percevejo adultos, em confinamento (para verificar a ação inseticida) e teste de livre escolha (para verificar a ação repelente). Os três extratos que mostraram melhores resultados foram selecionados para os testes com os organismos não alvo. Com relação à C. noackae, testes pré e pós-parasitismo, de confinamento e de livre-escolha foram realizados para verificar se os extratos afetariam a escolha do hospedeiro pelas fêmeas ou o desenvolvimento das fases imaturas do parasitoide. Para verificar se os extratos seriam tóxicos a G. domesticus, estes foram adicionados à dieta de aves juvenis por cinco dias. Parâmetros como peso, consumo de alimento, quantificação de enzimas séricas e análise histopatológica foram realizados. Por meio das análises cromatográficas, foram detectados os ácidos gálico, ferúlico, cafeico, cumárico e vanílico. Os extratos levaram à mortalidade de 100% dos insetos em até 49% do tempo, quando comparados com a testemunha, mas E. grandiflorus, Matricaria chamomilla e Maytenus ilicifolia destacaram-se mostrando efeito repelente, sendo selecionados para a próxima etapa. Nenhum destes afetou a escolha do hospedeiro pela fêmea ou a emergência dos parasitoides, quando comparado com a testemunha. Além disso, os extratos não causaram alterações em G. domesticus, em nenhum dos parâmetros avaliados. Desta forma, verificou-se que E. grandiflorus, Matricaria chamomilla e Maytenus ilicifolia têm potencial para serem utilizados no controle de T. peregrinus, bem como mostraram-se seguros para C. noackae e G. domesticus. / Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae ) is an insect from Australia which is causing severe damage to eucalyptus crops around the world. When feeding from the leaves sap, it causes bronzening, and in extreme cases, may lead to the tree death. Control methods have been studied and the most promising so far is the egg parasitoid Cleruchoides noackae (Hymenoptera: Mymaridae). Alternative products from plants with insecticidal properties could also be a viable option, and they might even be used concomitantly with C. noackae, aiming for a most effective control, but still safe for the environment. Thus, the objective of this work was to verify the action of 5% aqueous plant extracts of Matricaria chamomilla, Echinodorus grandiflorus, Punica granatum, Maytenus ilicifolia a n d Origanum majorana on T. peregrinus. In addition, we aimed to study the extracts potential toxicity to C. noackae and Gallus domesticus L., since the plant compounds might have negative effect upon the non-target organisms. At first, HPLC (High Performance Liquid Chromatography) was used to verify which phenolic compounds would be found in the plant extracts. These were tested on bronze bug adults, in confinement test (to verify the insecticidal action of the extracts) and free-choice test (to verify the repellency). The extracts that showed better results were selected for further tests with non-target organisms. Regarding C. noackae, pre-parasitism and post-parasitism, confinement and free-choice tests were performed to verify if the extracts would affect the host-choosing by the female or the development of the immature stages of the parasitoid. To verify if the extracts would be toxic to G. domesticus, the plant extracts were added to young birds feed for five days. Parameters such as weight gain, food intake, quantification of serum enzymes and histopathological analysis were carried out. HPLC analysis detected gallic, ferulic, vanillic, caffeic and cumaric acid in the extracts samples. All plant extracts tested reduced T. peregrinus survival, but E. grandiflorus, Matricaria chamomilla Maytenus ilicifolia had also a repellent effect, and were tested on the non-target organisms. None of these extracts affected neither the host choice by C. noackae nor adult emergency, when compared to the control group. In addition, the extracts did not cause alterations in any of the studied parameters. Thus, we verified that E. grandiflorus, Matricaria chamomilla and Maytenus ilicifolia have potential to be used to control T. peregrinus and are safe to C. noackae and G. domesticus.
166

A molecular phylogenetic study and the use of DNA barcoding to determine its efficacy for identification of economically important scale insects (Hemiptera: Coccoidea) of South Africa

Sethusa, Mamadi Theresa 15 July 2014 (has links)
Ph.D. (Zoology) / Scale insects, plant pests of quarantine importance, with specialised anatomy and unresolved phylogenetic relationships, are responsible for major economic losses to South Africa and its trading partners. These losses may reach critical levels if the pests are not timely identified and controlled. They are currently identified based on published keys of adult females, a process that takes three days to two weeks depending on the family and the life stage of interception. In addition, agricultural commodities are often contaminated with different life stages, males or damaged specimen of these pests, making identification difficult or impossible. As a result, shipments of agricultural produce are often rejected and trade disrupted. Furthermore, pest invasions do not only occur by importation via formal channels. At times pests cross boarders as contaminants of undeclared material and may again spread on their own as they naturally expand their range. This expansion may be negatively or positively influenced by other factors such as climate change. Resolving the challenges associated with identification, phylogenetic relationships and the limited knowledge of the effects of climate change on distribution range of scale insects are the main goals of this study. Specifically (i) the development of a rapid method of species identification, (ii) the relationship between and within three major scale insect families the Coccoidea, Diaspididae and Pseudococcidae and (iii) the effect of climate change on the future distribution range of scale insects in South Africa were explored...
167

A contribution to cabbage pest management by subsistence and small-scale farmers in the Eastern Cape, South Africa

Mkize, Nolwazi January 2004 (has links)
The interaction between farmers, agricultural scientists and extension workers is sometimes overlooked in agricultural entomology. In an attempt to respond to this reality this study examines some foundation of this interaction in relation to the pest management practices of subsistence and small-scale farmers and also highlights the problems that might arise in the implementation of IPM. Problems involving pests occurrence; language barriers; beliefs, knowledge and perception about insects, and visual literacy are examined. The thesis has a two-fold focus, firstly the study of pests on cabbages of subsistence farmers in Grahamstown and secondly a broader focus on other aspects such as cultural entomology, perception of insects and visual literacy specifically in relation to Xhosa speaking people in the Eastern Cape. The most important crop for emergent farmers in the Eastern Cape are cabbages, which have a variety of pests of which diamondback moths and are the most important. Traditional pest management practices tend to influence the development of IPM programmes adopted by these farmers. Eastern Cape farmers apply periodic cropping systems, which had an effect on the population densities of diamondback moth (DBM), other lepidopteran pests and their parasitoids. Considering the maximum population densities of DBM, which were 0.2 - 2.9 larvae/plant, there were no major pest problems. The availability of parasitoids, even in highly disturbed and patchy environments, showed good potential for biological control. Since some extension officers cannot speak the local farmers’ language, a dictionary of insect names was formulated in their language (isiXhosa) to assist communication. Response-frequency distribution analysis showed that the dictionary is essentially complete. The literal translations of some names show that isiXhosa speakers often relate insects to people, or to their habitat or classify them according to their behaviour. Farmers from eight sites in the Eastern Cape were interviewed regarding their knowledge and perception of insect pests and their control thereof. To some extent, farmers still rely on cultural control and have beliefs about insects that reflected both reality and superstition. There is no difference between the Ciskei and Transkei regions regarding insect-related beliefs. Farmers generally lack an understanding of insect ecology. There is a need for farmers to be taught about insects to assist with the implementation of IPM. Leftover pesticides from commercial farms or detergents are sometimes used to manage the pests. When training illiterate or semi-literate farmers, it is important to understand their media literacy so as to design useful graphic and object training media. Generally farmers showed that they either understand graphic or object media depending on the features of the insects being looked at. These findings are discussed with regard to the potential development of IPM training material for subsistence and small-scale farmers in a community.
168

The compilation of indigenous knowledge regarding insect pests in small-scale farming communities in North Eastern South Africa

Netshifhefhe, Shandukani Rudolf 30 June 2005 (has links)
Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Sustainable Insect Management))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted
169

Quantifying Asiatic garden beetle (<i>Maladera castanea</i>) populations and their impacts on commercial mint production

Connor Eric Sturr (17583585), Doug richmond (17583727), Elizabeth Y. Long (17583733), Christian Krupke (17583735) 07 December 2023 (has links)
<p dir="ltr">The Asiatic garden beetle (AGB), in its larval stage, has become an increasingly detrimental to the health of commercially grown mint in northern Indiana by feeding on their roots. In my research, I have optimized a method to quantify populations by determining the proper sample size to maintain accurate and precise estimates, determining the best sampling method and sampling scheme. Additionally, I established the relationship between AGB larval feeding and mint performance and have established a threshold of the average number of larvae required to cause significant yield loss. </p>
170

Ecology and management of bat communities to increase pest control in macadamia orchards, Limpopo , South Africa

Weier, Sina Monika 18 May 2019 (has links)
PhD (Zoology) / Department of Zoology / An ever growing human population and accelerating land use change is associated with the loss of species and their ecosystem services. Agricultural intensification has led to a worldwide threat of extinction to about one quarter of all bat species, despite the valuable ecosystem service of pest control provided by bats. The decline in bat populations is mainly attributed to the loss or fragmentation of habitats, roost sites and feeding opportunities related to agricultural intensification and land use change. Therefore, proactive management of bat communities in agricultural landscapes is essential. South Africa is the world’s largest producer of macadamias and the industry continues to grow. This study gains insight into the habitat use and foraging behaviour of insectivorous bat species on a temporal and spatial scale, in and around macadamia orchards in order to advise management strategies on how to increase bat activity and, possibly, pest control. It also focuses on the preferences of artificial roost sites used by insectivorous bats in macadamia orchards. The diet of insectivorous bat species is especially difficult to study and the least invasive tool to gain information is the study of bat faecal pellets. In order to provide evidence for the consumption of pest insect species by bats and thus incentive to farmers for a more integrated pest management approach (IPM), this study explored molecular approach to insectivorous bat diet analyses using fragment analysis of bat faecal pellets with fluorescent-labelled species-specific primers (designed for the CO I gene). This study was conducted in the subtropical fruit growing area of Levubu, Limpopo province, South Africa between the towns Thohoyandou (22°59'03.7 S, 30°27'12.8 E) and Makhado/Louis Trichardt (23°03'03.6 S, 29°55'12.7 E). Levubu also accounts for the second highest production of macadamia in South Africa. An introduction to the order Chiroptera and into the relevance of insectivorous bat species to agriculture as well as the importance of a more integrated pest management approach (IPM) focusing on bats is provided in Chapter One. Bats were acoustically monitored and light traps were used to catch arthropods during one annual cycle. I sampled five macadamia orchards once a month from September 2015 to August 2016 and used GIS and R to analyse both the general bat activity and foraging bat activity of the two main foraging guilds (open-air/clutter edge guild) in different land use types as well as total bat activity with respect to arthropod abundances. As reported in Chapter Two, results show that the overall clutter edge guild activity (number of passes) decreased with macadamia and orchard (all other fruit) cover in the macadamia high season (December to end of May) and increased with bush cover and distance to settlements (potential roosts) in the macadamia low season (June to end of November). Open-air guild activity increased with fallow cover (uncultivated grassland with scattered trees and shrubs) in the high season. Foraging activity (feeding buzzes) of the clutter edge guild increased with bush cover over the whole year. Total activity (both guilds) increased with abundance of true bugs (Hemiptera), including the main macadamia pests, and bush cover. Macadamia cover has a negative effect on the activity of the clutter edge guild in the high season, with low activity in the orchard center (high cover), and activity increasing in a linear way with decreasing orchard cover at the orchard edge (low cover). These results suggest that the clutter edge guild prefers foraging close to the edges of the orchards rather than in the center, while the open-air guild prefers semi-natural habitats (fallow). When numbers of pest arthropods drop in the macadamia orchards, the natural land use type, bush, becomes a more important foraging habitat and thereby increased the activity of the clutter edge guild. From June 2016 to July 2017, I scanned 31 bat houses, mounted on poles on six macadamia orchards, for bats or any other occupants such as wasps, birds and bees. Twenty-one multichambered bat houses of three slightly different chamber designs were erected on poles, in sets of three. Additionally, five bat houses of the type ‘Rocket box’, four bat houses in sets of two (black and white) and one colony bat house were erected. Bats were counted and visually identified to family or species level. From December 2016 to end of March 2017, three IButtons were installed to record temperature variation between one set of three bat houses. As reported in Chapter Three, results show that the central bat house in the set of three and the black bat house in the set of two had a significantly positive effect on bat house occupancy. There was a significant difference in the mean temperature between the houses in the set of three, with a significant difference in temperature of 0.46°C between the central and the first bat house. The three bat houses erected in sets varied slightly in their chamber design, with the central bathouse having the most chambers (six), while the bat houses to either side had less chambers (four), set at an angle or straight. This and the insulation to either side by the other bat houses is assumingly what caused the central bat house to be on average warmer. The Yellow-bellied house bat (Scotophilus dinganii) was by far the most recorded and the only species observed to co-habitat a bat house with another animal species, in particular honeybees. The study might confirm assumptions in that the microclimate of bat houses, respectively their insulation, sun exposure and color appear to be important factors influencing bat house occupancy. The two preferred bat houses in our study were the black, in the set of black and white, as well as the central, and on average warmest bat house, in the set of three. I collected bat faecal pellets with two different methods between July 2015 and April 2017 to determine the prevalence of pest insects in faecal pellets. Eighteen of the bat houses (in sets of three) on three different farms and two Egyptian slit-faced bat (Nycteris thebaica) roosts were fitted with trays in order to collect pellets from those occupied by bats. I noted occupancy of bat houses to species or family level to keep disturbance minimal. Additionally, I collected pellets from individuals captured by means of mist nets and harp traps. Four of the main pest-insects; the two-spotted stinkbug (Pentatomidae: Bathycoelia distincta), the green vegetable bug (Pentatomidae: Nezara viridula), the macadamia nut borer (Tortricidae: Thaumatotibia batrachopa) and the litchi moth (Tortricidae: Cryptophlebia peltastica), were collected from pheromone traps or after scouting for primer development and optimisation. After extracting DNA from the bat faecal samples the target regions were amplified in a multiplex PCR and fluorescently labelled PCR amplicons were analysed and interpreted. In order to verify multiplex analyses results, all samples were amplified with all four sets of primers in plates and those that produced amplicons were purified and sequenced. As reported in Chapter Four, results show that fragment analyses yielded a total of 63 out of 103 samples tested positive for pest insect species (61%) with a total of 92 positive fragments. Primer specificity could be confirmed to 100% for the sequences obtained for Bathycoelia distincta (26/26) and Nezara viridula (12/12) primers but not for all sequences obtained fot Cryptophlebia peltastica (18/30) and Thaumatotibia batrachopa (1/14) primers. One sample showed no positive fragments but contained a positive sequence for N. viridula. Three samples tested positive for one pest-species fragment but contained a positive sequence for a second pest-species (B. distincta, T. batrachopa and C. peltastica). Adding four positive fragments and one additional positive sequence to the data. This means that sequences of pest insect species were obtained from 54 out of the 103 samples (55.6%) with a total of 73 pest insect sequences. For the high season (December to end of May) a total of 37 positive fragments for the four pest insect species and 24 negative samples were yielded and for the a low season (June to end of November) a total of 36 positive fragments and 15 negative samples. Looking at the pest consumption of the different bat species or families, our results show that all of them foraged on pest insect species. Whereas, all species and families except Myotis bocagii and Rhinolophus simulator (for which N<2) foraged on both the Lepidopteran and Hemipteran pest species. Therefore, all families of bats of which faecal pellets were analysed for this study (Molossidae, Nycteridae, Rhinolophidae and Vespertilionidae) foraged on one or more of the four pest insect species. In summary, Chapter Five concludes that natural and semi-natural vegetation promote bat activity in macadamia orchards, and potentially bats' provision of the ecosystem service of pest control. In times of accelerating land use change, remnants of natural vegetation are important refuges and need to be maintained or restored to conserve bat species and promote their ecosystem services. The study also shows that bat activity might be improved by adding roosting opportunities to orchards. Warm and well-insulated bat houses mounted freestanding on poles and in sets appeared to work best in northern South Africa. Further research on co-habitation of bat houses and displacement behaviour as well as the potential importance of altitude and distance to water is needed. All of the species or families of bats from which faecal pellets were collected have been confirmed to forage on at least one of the four pest insects and the bat species have shown to be much more generalist and presumably opportunistic feeders than previously assumed. Thus, this study provides incentive and advice to farmers for a more integrated pest management approach (IPM). / NRF

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