TCC - Bacharelado em Ciências Biológicas (Sede)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/412
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Item Monitoramento da resistência de populações de traça-do-tomateiro, Tuta absoluta (Meyrick, 1917), a metoxifenozida(2019-07-13) Dantas, Kayo César Tavares; Siqueira, Herbert Álvaro Abreu de; Silva, Paolo Augustus Freitas; http://lattes.cnpq.br/4296419325067163; http://lattes.cnpq.br/6587276520956028; http://lattes.cnpq.br/2049478457196226Brazil is currently the ninth largest tomato producer with approximately 4.3 million tons of fruit produced. The tomato crop presents several phytosanitary problems, among which is the occurrence of pest insects. Due to the severity of its damages, Tuta absoluta can be considered one of the main pests that affect the tomato crop and large outbreaks can lead to total loss of production of this crop. Although academic research contributes to control alternatives in integrated pest management, the main method used is chemical control. However, the continued use of insecticides is undesirable due to several aspects and the development of resistant populations. For this reason, monitoring studies should be carried out constantly to assist in the management of populations that present this phenotype in order to minimize possible damages. The objective of this work was to monitor T. absoluta populations with insect growth inhibitors (IGRs). The bioassays were conducted using the dose recommended by the manufacturer of the product methoxyfenozide (120 mg a.i./L) and a diagnostic dose of the same product for identification of the sensitive populations (10 mg a.i./L). After obtaining the results, the populations that obtained more distinct responses were submitted to concentration-response assays using eight concentrations to obtain the LC50. Among the 19 populations tested, only eight (GML, MGM, MGMSEL, SUM, GML2SEL, IRA, IRANO, AMD + PES) presented mortality above 80%. With regard to diagnostic dose, only five populations presented mortality above 80% (GML, MGM, MGMSEL, IRA, AMD + PES). The Gameleira population was used as a reference for susceptibility to methoxyfenozide. The LC50 obtained by concentration-response bioassays were 0.51 and 282.14 mg a.i./L for the populations of Gameleira and Guaraciaba, respectively. The resistance ratio between the two tested populations was 551.90 times. The probability of cross-resistance with the insecticide tebufenozide was tested and the LC50 obtained were 35.67 and 348.19 mg a.i./L for the populations of Gameleira and Guaraciaba, respectively. The resistance ratio for these populations to tebufenozide was 681.08. Thus, we can conclude a probable cross-resistance between methoxyfenozide and tebufenozide and the use of these products should be discontinued in these regions.Item Análise da atividade larvicida de hidrazidas contendo anéis do 1,2,4-oxadiazol e estudo das alterações morfo-histológicas em larvas de Aedes aegypti L. (Diptera, Culicidae)(2018-08-15) Nascimento, Jéssica da Silva; Oliveira, Lourinalda Luiza Dantas da Silva Selva de; Navarro, Daniela Maria do Amaral Ferraz; http://lattes.cnpq.br/6866049887225410; http://lattes.cnpq.br/7013867423178814The control of Aedes aegypti is now a major public health challenge because it’s responsible for important arboviruses such as: Dengue, Chikungunya, Zika and Urban Yellow Fever. In this work, we propose a study of the structure-activity relationship of 15 hydrazides against A. aegypti larvae, aiming to identify structural characteristics responsible for the larvicidal activity of the compounds. Fourth instar larvae were submitted to the compounds for 48 hours at different concentrations and then the LC50 was determined. Of the studied compounds, 9 presented considerable potential in the control of A. aegypti (LC50 <100ppm). The compound identied as HCBA presented greater larvicidal activity when compared to the others (LC50 = 20.63ppm) and aroused interest in understanding its mechanism of action. Larvae in the 4th instar were submitted to HCBA (20.63ppm), where they remained for 24 hours. The larvae that reached sublethal state were collected, xed in formoline, included in resin, sectioned, the blades stained by toluidine blue and analyzed by light microscopy. The morphohistological changes of the larvae submitted to the treatment were: high vacuolization in the cytoplasm and disorganization of the epithelium. These results demonstrate that the P-Cloro (HCBA) compound may be effective in controlling A. aegypti for promoting changes at the mesenteric level.Item Avaliação de métodos de manutenção de Bacillus thuringiensis var. israelensis(2018) Xavier, Ana Carolina Cavalcante; Porto, Ana Lúcia Figueiredo; Oliveira, José de Paula; http://lattes.cnpq.br/3540150611094753; http://lattes.cnpq.br/4989617783837981; http://lattes.cnpq.br/4483834181760838Due to the rising environment pollution and growth in the cases of health problems through the indiscriminate use of chemical pesticides, Bacillus thuringiensis based insecticides have been widely used as na alternative method to combat pests and vectors. Bacillus thuringiensis (also know as Bt ) is a bacterium that produces crystalline protein inclusions which are very toxic to many insect vectors and pests, and harmless to humans and animals. The proper maintenance of this microorganism is fundamental for the formulation success, therefore, the method must guarantee the highest yield of biomass and must also preserve the proteins produced by it.The most commonly used maintenance methods are with the Bt kept on the surface of paper disks, in frozen pellet, continuous filings with the lyophilized culture, and with the culture kept submerged in mineral oil. This work had as objective to determine the method that provides greater yield of bacterial biomass. Thus, three methods of maintaining Bacillus thuringiensis var. israelensis (cepa H-14/ IPA-CAV-Bti-0008): in paper disks, by freezing the pellet at -20 ºC and under mineral oil. Cultures were carried out in a bioreactor operating in batch discontinuous for each of the evaluated methods. Samples were taken every two hours to determine the growth curve of the microorganism by optical density (O.D). The analyzed parameters of pH, dissolved oxygen were automatically monitored by means of electrodes coupled to the equipment and inserted in the culture. The total yield of the bacteriaa biomass was determined by means of the flocculation / sedimentation process, with subsequent drying and determination of the dry mass. At the end of the cultures a polyacrylamide gel electrophoresis was performed to verify the profile of the proteins produced by the bacillus in each of the three methods. It was obtained that the method of preservation in mineral oil was the most efficient with regard to the higher yield of biomass, although the methods of maintenance in paper disc and the frozen pellet have the advantage of needing less storage space, risk contamination and cost.