• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 76
  • 70
  • 61
  • 29
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 5
  • 2
  • Tagged with
  • 292
  • 292
  • 168
  • 59
  • 57
  • 56
  • 55
  • 36
  • 36
  • 34
  • 32
  • 29
  • 29
  • 28
  • 23
  • 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.
121

INTERRELATIONSHIP OF A PARASITOID, HYPOSOTER EXIGUAE, PATHOGEN, BACILLUS THURINGIENSIS, AND HOST, HELIOTHIS VIRESCENS.

Thoms, Ellen Mary. January 1982 (has links)
No description available.
122

THE EFFECT OF PHOTOPERIOD AND TEMPERATURE UPON ADULT ECLOSION OF THE SWEETPOTATO WHITEFLY, BEMISIA TABACI (GENNADIUS).

Hoffman, Christopher John. January 1985 (has links)
No description available.
123

Success of development and extent of feeding damage of stored-product insects in cultivars of sorghum and millet

Sinada, Nour Awad Elkarim. January 1986 (has links)
Call number: LD2668 .T4 1986 S56 / Master of Science / Entomology
124

Genome analysis of an entomopathogenic nematode belonging to the genus Oscheius and its insect pathogenic bacterial endosymbiont

Lephoto, Tiisetso Elizabeth 10 May 2016 (has links)
A thesis submitted to the Faculty of Science under the school of Molecular and Cell Biology in fulfilment for requirements for Doctor of Philosophy Degree. February 2016 / The use of synthetic chemical pesticides has several negative implications for the Agricultural industry, which include the development of resistance to the insecticides, crop contamination and the killing of non-target insects. This has brought many scientists in the field of nematology and entomology to investigate biological control agents which can help solve identified challenges and these biocontrol agents have also included entomopathogenic nematodes. The majority of entomopathogenic nematodes species that have been isolated belong to Heterorhabditids and Steinernematids which act as vectors for insect pathogenic bacteria species belonging to the genera, Photorhabdus and Xenorhabdus, respectively. However, other species of nematodes, one of which includes a strain of Caenorhabditis briggsae, have also been shown to act as a vector for an insect pathogenic strain of Serratia marcescens. Oscheius sp. TEL-2014 EPNs have been observed to act as vectors for insect pathogenic bacteria belonging to the genus Serratia. In this study a novel insect pathogenic Serratia sp. strain TEL was isolated from the gut of infective juveniles belonging to a species of Oscheius sp. TEL-2014. Next generation sequencing of the bacteria was conducted by generating genomic DNA paired-end libraries with the Nextera DNA sample preparation kit (Illumina) and indexed using the Nextera index kit (Illumina). Paired-end (2 × 300 bp) sequencing was performed on a MiSeq Illumina using the MiSeq reagent kit v3 at the Agricultural Research Council Biotechnology Platform. Quality control and adapter trimming was performed and the genome was assembled using SPADES. 19 contigs were generated with an average length of 301767 bp and N50 of 200,110 bp. The genome of the Serratia sp. TEL was found to be 5,000,541 bp in size, with a G+C content of 59.1%, which was similar to that of other Serratia species previously identified. Furthermore, the contigs were annotated using NCBI Prokaryotic Genome Automatic Annotation Pipeline. Features of the annotated genome included protein encoding sequence or genes, rRNA encoding genes, tRNA encoding genes, ncRNA sequences and repeat regions. 4,647 genes were found and 4,495 were protein-coding sequences (CDS). The genome contains 36 pseudo genes, 2 CRISPR arrays, 13 rRNA genes with five operons (5S, 16S, 23S), 88 tRNAs genes, 15 ncRNA sequences and 9 frameshifted genes. Several genes involved in virulence, disease, defense, stress response, cell division, motility and chemotaxis were identified. This genome sequence will allow for the investigation of identified genes and that will be critical in furthering the understanding of the insect pathogenicity of Serratia sp. strain TEL. Furthermore, it will provide additional genomic insights about the insect-nematode interactions and thus help us improve their ability to be used as biological control agents in agricultural industries. Oscheius sp. TEL-2014 was tested for its entomopathogenicity and it was found that this species was able to infect and kill two model insects Galleria mellonella and Tenebrio molitor. This new nematode species brought 100% mortality within 72 h post-exposure in G. mellonella and whereas, within 96 hours in T. molitor. Following morphometrics analysis of Oscheius sp. TEL-2014 it was concluded that this nematode is described as a novel entomopathogenic nematode species based on its morphometrics and 18S rRNA gene sequence originality. Whole genome sequencing of Oscheius sp. TEL-2014 inbred lines (7 and 13) was performed using Illumina Hiseq sequencing system and paired ends library preparation protocol. Sequencing reads assembled on Velvet resulted in generation of 75965 contigs (line 7) and 53190 contigs (line 13). Gene prediction tools showed that proteins involved in gene expression and DNA replication are present in Oscheius sp. TEL-2014. The draft genome of Oscheius nematodes will support the improvement and initiation of further studies intended to help us understand the molecular and metabolic processes in this genus.
125

Efeito do glyphosate em plantas daninhas da família poaceae submetidas a diferentes potenciais hídricos do solo /

Silva Junior, Antonio Carlos da January 2018 (has links)
Orientador: Dagoberto Martins / Banca: Maria Renata Rocha Pereira / Banca: Robinson Luiz de Campos Machado Pitelli / Banca: Eduardo Custodio Gasparino / Banca: Lucas Perim / Resumo: A ação de herbicidas sobre plantas daninhas que se desenvolvem sob déficit hídrico pode ser comprometida, pois as rotas de penetração de herbicidas como o glyphosate são reduzidas em razão da menor hidratação da cutícula nessas plantas. Avaliou-se nesse estudo a eficiência de controle do herbicida glyphosate em quatro espécies de plantas da família Poaceae quando submetidas a distintos déficits hídricos. Os estudos foram conduzidos em casa-de-vegetação sendo que as espécies estudadas foram: capim-colonião (Megathyrsus maximum), capim-colchão (Digitaria nuda), capim-massambará (Sorghum halepense) e capim-braquiária (Urochloa ruziziensis). As plantas foram submetidas a três condições hídricas do solo [sem restrição hídrica (-0,03 MPa), déficit hídrico intermediário (-0,07 MPa) e alta restrição hídrica (-1,5 MPa)], aplicou-se três doses do herbicida glyphosate (0,0; 270,0 e 540,0 g e.a. ha-1) e em dois estádios fenológicos de desenvolvimento da planta (4-6 folhas e 1-3 perfilhos). O manejo hídrico teve início quando as plantas apresentaram duas folhas desenvolvidas. Foram realizadas avaliações visuais de controle aos 7, 14, 21 e 35 dias após a aplicação do herbicida; analisou-se ainda os parâmetros morfofisiológicos área foliar específica, condutância estomática e a diferença de temperatura do ambiente com a temperatura foliar no dia da aplicação do herbicida, bem como a matéria seca da parte aérea e da raiz ao final do estudo. Os resultados obtidos de controle e matéria seca fo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The action of herbicides on weeds that develop under water deficit can be compromised, the penetration routes of glyphosate herbicide are reduced due to the less hydration of the cuticle in these plants. The control efficiency of glyphosate herbicide in four species of plants of the Poaceae when submitted to different water deficits was evaluated in this study. The studies were carried out in a greenhouse and the species studied were: guineagrass (Megathyrsus maximum), naked crabgrass (Digitaria nuda), johngrass (Sorghum halepense) and congograss (Urochloa ruziziensis). In the treatments, the plants were submitted to three soil water conditions (no water deficit (-0.03 MPa), intermediate water deficit (-0.07 MPa) and high water restriction (-1.5 MPa)), three doses of glyphosate herbicide, (0.0, 270.0 and 540.0 g e.a. ha-1) and two phenological stages of plant development (4-6 leaves and 1-3 tillers). Water management started when the plants had two leaves developed. Visual evaluations were carried out at 7, 14, 21 and 35 days after application of the herbicide; the specific leaf area, stomatal conductance and the temperature difference of the environment with the leaf temperature on the day of application of the herbicide, as well as the dry matter of the aerial part and of the root were analyzed at the end of the study. The results of control and dry matter were submitted to analysis of variance by the "F" test and the means were compared by the Student "t" test (p> 0.05). T... (Complete abstract click electronic access below) / Doutor
126

Influence of pupal age on the response of the almond moth, Cadra cautella (Walker), to gamma radiation

Amoako-Atta, Boakye January 2010 (has links)
Digitized by Kansas Correctional Industries
127

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae) : caracterização macroscópica e determinação de inseticida e época de aplicação para controle /

Alencar, Marina Aparecida Viana de. January 2016 (has links)
Orientador: Nilza Maria Martinelli / Coorientador: Marcelo da Costa Ferreira / Banca: Antonio Carlos Busoli / Banca: Ana Lúcia Benfatti González Peronti / Banca: Leila Luci Dinardo-Miranda / Banca: Fernando Cesar Pattaro / Resumo: O objetivo foi descrever características morfológicas para reconhecimento de adultos de Sphenophorus levis, e avaliar o inseticida mais adequado de acordo com a época de aplicação para o controle. Para as análises morfológicas foram coletados 20 machos e 20 fêmeas de S. levis e de Metamasius hemipterus. A caracterização macroscópica das espécies foi realizada a partir de revisão da literatura e observações adicionais de caracteres de importância taxonômica nos espécimes estudados. A eficiência de inseticidas no controle de S. levis foi avaliada em dois experimentos, um com aplicação em dezembro e outro com aplicação em junho. Foram realizados nove tratamentos, compostos por oito controles químicos e uma testemunha. Realizou-se amostragem prévia antes das aplicações, as quais foram realizadas em filete continuo, e três avaliações após a aplicação dos inseticidas, contabilizando o número de formas vivas do inseto e número de tocos totais e atacados. No final da safra foi realizado biometria e análise tecnológica. O delineamento estatístico utilizado foi em blocos ao acaso com quatro repetições, em soqueira. Os dados foram analisados a Tukey a 5% de significância. A descrição dos caracteres presentes na antena, pronoto, abdômen e forma do pigídio, foram importantes para a diagnose de cada espécie. As formas do pigídio, bem como a distribuição das cerdas no mesmo, propiciaram a determinação do sexo para ambas as espécies. Os produtos/misturas utilizados não sofreram influência da época de aplicação e não foram eficientes para o controle de Sphenophorus levis com a metodologia empregada. Faz-se necessários trabalhos com outras metodologias de aplicação para observar o efeito dos produtos/misturas utilizados / Abstract: The objective was to describe morphological characteristics for recognition Sphenophorus levis adults, as well as to assess the most appropriate insecticide according to the time of application for the control this pest. For morphological analysis were collected 20 males and 20 females of S. levis and Metamasius hemipterus. The macroscopic characterization of these species was started from literature review and additional comments from characters of taxonomic significance about the studied specimens. The efficiency of insecticides the controlling S. levis was evaluated in two experiments with application in december and the other with application in june. Were performed nine treatments, composed by eight chemical controls and a control. Was conducted previous sampling, the aplications were performed under continuous fillets. Three evaluations were carried out after the application, counting the number of insect life forms and the total number of stumps and attacked stumps. At the end of the harvest it was held biometrics and technological analysis. The design utilized was randomized block design with four replications, in ratoon. The data were analyzed by Tukey test at 5% significance. The characters present at the antenna, pronotum, abdomen, and description of the pygidium, were important for the diagnosis of each species. The pygidium form and the distribution of the bristles led to the determination of sex in both species. Products/mixtures used do not suffer from influence of application time and were not efficient for control Sphenophorus levis with the methodology employed. It is necessary, work with other application methods to observe the effect of products/mixtures used / Doutor
128

The effects of coypu Myocaster coypus (nutria) trapping on the water quality of South Johnson Creek, Beaverton, Oregon

Frankel, Deborah Jean 01 January 2007 (has links)
Nutria are semi-aquatic rodents, non-native to Oregon. They are an invasive species that damage stream banks with burrowing and cause destruction of native vegetation; activity that may cause deterioration of stream water quality. I hypothesized that my study's duration and pattern of nutria trapping along South Johnson Creek would be sufficient to lead to a significant change in turbidity, dissolved oxygen (DO), total dissolved solids (TDS), total solids (TS), and total suspended solids (TSS).
129

Efficacy evaluation of Mohlolo Insecticide Bait on German Cockroach, Blattella Germanica L

Mbowane, Clarah January 2014 (has links)
Thesis (M.Sc. (Plant Production)) -- University of Limpopo, 2014 / In most cases the discipline plant protection is restricted to the protection of propagules, the plants and their produce in storage, while excluding the protection of processed (cooked) food from contaminants. Generally, the German cockroach (Blattella germanica L.) is a serious contaminant of processed food and had recently been viewed as a pest worthy of control in plant protection when viewing the entire value chain of agricultural commodities. Due to the nature of the pest, it is quite difficult to control using registered agrochemicals on the market. An entrepreneur in the rural areas of Limpopo Province developed bait for cockroach control, which was code named Mohlolo during efficacy trials. The use of baiting in cockroach management is currently the sought after approach in the world where cockroaches are problematic. Bait has the advantage over liquid or dust formulations because baiting requires shorter service, has shown increased efficacy, and has reduced environmental contamination. The objectives of this study were to determine whether the effect of MIB would be age related in the suppression of populations of B. germanica under laboratory conditions, and also to investigate whether MIB would reduce populations of B. germanica in residential areas. Five concurrent B. germanica age-related experiments were run in a complete randomized design. 1-d, 2-d, 3-d, 4-d, 5-d old nymphs and adult German cockroach experiments were conducted at Limpopo Agro-Food Technology Station (LATS) laboratory, (53’21,41” S/29 23o 44’19,95”E) hosted at the University of Limpopo. Each age group consisted of 10 nymphs and was put in 250 cm3 container that contained xv Mohlolo insecticide bait (MIB). One gram (1 g) of Mohlolo insecticide bait and moistened cotton wick were put at the bottom centre of the 250 cm3 containers containing nymphs based according to their respective ages. Residential experiments were conducted at UL student apartments. Two Bait containers were then placed in the kitchen, lodge, bathroom and bedroom. In the kitchen MIB containers were put behind the cooking stove and refrigerator, in the lodge the bait was placed next to the study table (because most study tables are also used during the eating time). In the bathroom the baits were put next to toilet seat and lastly in the bedroom, the bait was placed next to study table. According to the results, 100% mortality of 1-, 2-, 3-, 4-, 5-days nymphs and adult B. germanica was obtained after 7th, 2nd 3rd 3rd and 4th day, whereas LT50 values ranged from half a day to one and half (1.5) day. The study also demonstrated that B. germanica populations had high LT50 and LT100 values in residential areas compared to LT50 and LT100 values obtained in the laboratory experiments. This is probably due to the fact that residential areas that have low levels of sanitation availed the cockroaches with an opportunity to choose from many foods hence, it reduced the probability for cockroaches to feed on Mohlolo insecticide bait in the respective apartments. Results of this study showed that, Mohlolo bait toxicity and effectiveness as a control agent can reduce infestation of cockroaches in all developmental stages when applied at small quantity. Providing results of this study would provide information on resistance and tolerance of B. germanica nymphs and adult population against MIB in the xvi laboratory and residential areas. It would also provide biological information on the efficacy of MIB against the German cockroaches.
130

Studies on soil-fumigation with vapam for controlling soil borne diseases of peas

Nath, Jagdishwar. January 1959 (has links) (PDF)
[Typewritten] Includes bibliography.

Page generated in 0.0309 seconds