Submitted by (edna.saturno@ufrpe.br) on 2016-11-24T16:14:21Z No. of bitstreams: 1 Gustavo Neto Bandeira.pdf: 480654 bytes, checksum: e048697a909f44f9284d66f9f557a5c9 (MD5) / Made available in DSpace on 2016-11-24T16:14:22Z (GMT). No. of bitstreams: 1 Gustavo Neto Bandeira.pdf: 480654 bytes, checksum: e048697a909f44f9284d66f9f557a5c9 (MD5) Previous issue date: 2009-07-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The family Brassicaceae is one of the most economically important in the world, having as their main pest to Plutella xylostella (L.) (Lepidoptera: Plutellidae), which causes great damage to the crop with up to 100% of yield losses. In order to investigate alternatives to synthetic insecticides, medicinal plants have been in recent years in search of compounds with insecticidal properties, repellent, fumigant or that act directly on the disruption of biological cycles of pests such as P. xylostella. Furthermore, the literature is scarce when it comes to studies with the use of essential oils and organic extracts to verify their potential insecticide. Accordingly, the medicinal plants chosen to carry out the research potential of the insecticide are the following families: Tiliaceae (Muntingia calabura) Piperaceae (Piper marginatum) Rutaceae (Citrus reticulata x Citrus sinensis, C. reticulata Blanco) and Myrtaceae (Melaleuca leucadendron). The bioassays carried out indicated that P. xylostella larvae were susceptible to all selected plant extracts and oils tested. Furthermore the extract etanolic of flowers (MCEFL) achieved 99.5% of larvalmortality and a lethal concentration LC50 estimated of 1.63 mg/mL. In addition the extract MCEFL caused 100% of pupal inviability on treated larvae. The development of larvae increased 1.62 days when being treated with the extract hexanic of fruits (MCHFR) compared to the untreated ones. P. xylostella was susceptible to all essential oils tested. Among the oils the mosttoxic was those prepared from Citrus (LC50 of 0.55ppm for C. reticulata and 0,78ppm for C. sinensis x C. reticulata). Also, the oil from C. reticulata x C. sinensis increased larval development in 2.2 days compared to the other oils and untreated larvae. / A família Brassicaceae é uma das mais economicamente importantes no mundo, tendo como sua principal praga a Plutella xylostella (L.) (Lepidoptera: Plutellidae), que causa grandes danos à cultura chegando a atingir até 100% de perdas na produção. Tendo em vista a investigação de alternativas aos inseticidas sintéticos, as plantas medicinais tem sido alvo nos últimos anos na busca de compostos com propriedades inseticidas, repelentes, fumigante ou que atuem diretamente na interrupção dos ciclos biológicos de pragas, como a P. xylostella. Por outro lado, a literatura é escassa, quando se trata de estudos com o uso de óleos essenciais e extratos orgânicos para verificar seu potencial inseticida. Nesse sentido, as plantas medicinais escolhidas para realização da investigação do potencial inseticida foram: Muntingia calabura; Piper marginatum; Citrus reticulata x Citrus sinensis, C. reticulata Blanco e Melaleuca leucadendra. Os experimentos realizados com extratos e óleos das diferentes plantas selecionadas mostraram que as larvas de P. xylostella foi sensível a todos. Com relação ao extratos, o mais tóxico foi o extrato etanólico da flor, que promoveu 99,5% de mortalidade de larvas e uma CL50 estimada de 1,63 mg/mL. Na duração da fase larval, o extrato hexânico do fruto prolongou essa fase em 1,62 dias em relação ao controle e quanto à mortalidade da fase pupal, o extrato etanólico da flor inviabilizou completamente a emergência de adultos. As larvas de P. xylostella foi sensível atodos os óleos testados. Os mais tóxicos foram os óleos de Citrus (CL50 0,55ppm para C. reticulata e CL50 0,78ppm para C. sinensis x C. reticulata). Quanto a duração da fase larval, o melhor resultado foi observado para o óleo de C. reticulata x C. sinensis, que apresentou um incremento de 2,2 dias com relação ao controle.

Submitted by (edna.saturno@ufrpe.br) on 2016-12-01T15:25:09Z No. of bitstreams: 1 Hugo Bolsoni Zago.pdf: 898683 bytes, checksum: a6a8ab8ddd71419162e9faad7a47b971 (MD5) / Made available in DSpace on 2016-12-01T15:25:09Z (GMT). No. of bitstreams: 1 Hugo Bolsoni Zago.pdf: 898683 bytes, checksum: a6a8ab8ddd71419162e9faad7a47b971 (MD5) Previous issue date: 2008-02-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The diamondback moth (DBM), Plutella xylostella (L.) is a key pest of cabbage in the Agreste area of Pernambuco state. Despite of being a key pest, the DBM is attacked by several natural enemies including the egg parasitoid, Trichogramma. In addition, formulated insecticides with different strains of Bacillus thuringiensis Berliner are widely used to control the larval stages. Thus, this research aimed to search for a local species or population of Trichogramma; to study its biological characteristics and parasitism on DBM eggs; to investigated the oviposition site preference of DBM and its parasitism by Trichogramma on cabbage plants at pre- and post-head formation in the field and; to investigate the susceptibility of 10 Brazilian populations of DBM relative to the commercial formulations of B. thuringiensis var. kurstaki (Dipel®WP) (Btk) and B. thuringiensis var. aizawai (Xentari®WG). Trichogramma survey was conducted in areas with organic-growing vegetables, Chã-Grande County, PE. The collected species wasTrichogramma pretiosum Riley. The biological characteristics and parasitism were similar for this population parasitizing DBM eggs and eggs of the laboratory standard host, Anagasta kuehniella (Zeller). In the field, the parasitism of DBM eggs by T. pretiosum was associated with the moth oviposition site preference and exhibited a positive relationship with egg availability; but, the eggparasitism rate was density independent across both plant ages. The oviposition of DBM on cabbage plants at pre-head formation and its parasitism was equally distributed across the plant leaves. At this plant age, the basal part of the leaf and the upper leaf surface were the preferred places for oviposition and parasitism. Plants at post-head formation stage had higher oviposition and parasitism on the central leaf wrapping the head and in the upper leaf surface. The susceptibility of DBM to the insecticides Btk and Bta resulted in significant levels of resistance. The resistance ratio was 180 and 999 times to the recommended rates of Bta and Btk, respectively. Furthermore, variation of larvae and adults regarding walking and oviposition behavior were observed among the populations using treated and untreated cabbage leaf discswith Bta and Btk. / traça-das-crucíferas, Plutella xylostella (L.) é praga-chave do repolho no Agreste de Pernambuco. Apesar da condição de praga-chave, ela possui vários inimigos naturais incluindo o parasitóide de ovos Trichogramma. Além de que seu controle é feito com inseticidas à base de Bacillus thuringiensis Berliner. Deste modo, esta pesquisa teve como objetivos realizar a coleta de uma população Trichogramma spp. associado a cultivo orgânico de brássicas no Agreste de Pernambuco; estudar a biologia e o parasitismo da espécie coletada, no hospedeiro P. xylostella, comparado ao hospedeiro de criação Anagasta kuehniella (Zeller) (Lep.: Pyralidae); investigar a distribuição da oviposição de P. xylostella e seu parasitismo por Trichogramma em repolho antes e após formação da cabeça e; investigar a susceptibilidade de populações de P. xylostella as formulações comerciais de B. thuringiensis var. kurstaki (Dipel® WP) (Btk) e B. thuringiensis var. aizawai (Xentari® WG) (Bta). Foram realizadas coletas de Trichogramma em cultivo orgânico nomunicípio de Chã-Grande, PE. A coleta resultou na espécie Trichogramma pretiosum Riley (Hym.: Trichogrammatidae). As características biológicas e o parasitismo desta população em ovos de P. xylostella e no hospedeiro alternativo, Anagasta kuehniella (Zeller), foram similares. O parasitismo de ovos de P. xylostella por T. pretiosum, em campo, foi associado ao local de maioroviposição da praga e mostrou-se positivamente correlacionado com a quantidade de ovos depositados pela praga em diferentes estruturas da planta, porém com taxas de parasitismo independentes da densidade. A oviposição de P. xylostella e seu parasitismo por T. pretiosum em plantas de repolho antes da formação da cabeça foram igualmente distribuídas entre as folhas. A parte basal e a epiderme superior das folhas foram às localidades preferidas para oviposição e parasitismo, respectivamente. Plantas após a formação de cabeça tiveram maior oviposição e parasitismo na folha central envolvendo a cabeça e na epiderme superior desta folha. Com relação à susceptibilidade de P. xylostella aos inseticidas Dipel e Xentari, foram constatados consideráveis níveis de resistência. A razão de resistência de até 180 e 999 vezes a concentração recomendada de Dipel e Xentari, bem como foram observadas variações no comportamento de caminhamento das larvas e preferência de oviposicão em discos foliares tratados e não tratadoscom Dipel e Xentari entre as populações estudadas. Assim, neste estudo foi identificado populações da traça-das-crucíferas com significativos níveis de resistência a formulações comercias de B. thuringiensis.

L'espèce Plutella xylostella (L.) (Lepidoptera : Plutellidae) défoliatrice des choux constitue surtout un problème dans les régions tropicales et subtropicales. La lutte chimique a rapidement montré ses limites du fait de l'apparition de résistance dans les populations. Des moyens de lutte alternatifs ont été mis en place, impliquant principalement des insectes parasitoïdes, parmi lesquels Oomyzus sokolowskii (Kurdjumov) (Hymenoptera : Eulophidae) et Cotesia vestalis (Haliday) (Hymenoptera : Braconidae) qui sont les plus couramment utilisés en raison de leur spécificité envers P. xylostella. Afin de contribuer à une meilleure connaissance du contrôle de la teigne en région tropicale, nous avons étudié les relations hôteparasitoïde entre P. xylostella et O. sokolowskii d'une part, et P. xylostella et C. vestalis d'autre part, en conditions de laboratoire et sur le terrain au Sénégal et au Bénin. Au Sénégal, quatre espèces de parasitoïdes sont présentes sur les chenilles : O. sokolowskii, Apanteles litae, C. vestalis et Brachymeria citrae. Au Bénin, seule l'espèce C. vestalis est présente. Au Sénégal comme au Bénin, les facteurs climatiques contribuent au développement de la teigne et les précipitations ne régulent pas les populations du ravageur. Dans ces deux pays, la teigne n'est pas contrôlée par ses ennemis naturels. La lutte biologique par conservation y est à prendre en considération et l'utilisation de plantes compagnes cultivées en association avec le chou peut être envisagée pour réduire les populations de la teigne. Les études en laboratoire ont montré qu'Oomyzus sokolowskii est un parasitoïde larvo-nymphal performant. ConcernantC. vestalis, les femelles détectent et reconnaissent leur hôte grâce aux lipides cuticulaires émis par les chenilles. Des marqueurs moléculaires (isozymes et ISSR) ont confirmé une forte variabilité entre les populations de P. xylostella à l'échelle mondiale, les populations d'Australie et du Japon étant très différentes des autres et formant deux groupes distincts. La structuration des populations semble influencée par le type de climat : tropical et non tropical.

Nabis kinbergii is a native polyphagous predator in Australia. It has been found in all states and territories of Australia. N. kinbergii has been regarded as an efficient predator of many insect pests in lucerne, cotton and particularly brassica crops. The circadian rhythms, the effects of different prey on development and reproduction, and prey preferences of N. kinbergii have not been studied in South Australia. These are the subjects of this thesis. N. kinbergii is more active at night than in the day. They seemed to be still more frequently at dawn and more active at dusk under natural environmental conditions. Yet, their behaviour was possibly different when they were held in a controlled environment with artificial light. Under both natural and artificial lighting conditions, they would spend more time moving on plants at night. They spent less time moving than other activities. Furthermore, they were more active during the second day of the observations, probably because of the hunger. A mixed diet including Plutella xylostella, Myzus persicae and Brevicoryne brassicae brought the most significant positive influences to the development, survival and longevity of N. kinbergii. It had a shorter preoviposition period and greater egg production when fed on P. xylostella than when fed on M. persicae. Among the three prey, B. brassica was the poorest food because the survival rate between egg hatch and adult eclosion was only 7.5 %, compared to 85 %, 92.5 % and 97.5 % when N. kinbergii fed on M. persicae, P. xylostella and a mixed diet, respectively. Evidence of prey preference was exhibited by N. kinbergii. B. brassica seemed to be the least preferred food. N. kinbergii possibly attacked less mobile prey and delayed eating prey with poor nutrition or that were toxic. In wind tunnel experiments, N. kinbergii may have been attracted by plant volatiles rather than prey odour. These findings may help to refine the timing of experiments and improve the understanding of the role of this predator in integrated pest management. / Thesis (M.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore. In all three study populations, flowering time was negatively related to plant fitness, but in only one of the populations, significant selection on flowering time was detected when controlling for size prior to the flowering season. The results show that correlations between flowering time and plant fecundity may be confounded by variation in plant size prior to the reproductive season. A field experiment detected conflicting selection on germination time: Early germination was associated with low seedling survival, but also with large leaf rosette before winter and high survival and fecundity among established plants. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination, and that the optimal timing of germination should vary in space and time as a function of the relative strength of selection acting during different life-history stages. Experimental leaf damage demonstrated that tolerance to damage was lowest among vegetative plants early in the season, and highest among flowering plants later in the season. Given similar damage levels, leaf herbivores feeding on plants before flowering should thus exert stronger selection on defence traits than those feeding on plants during flowering. Resistance against larval feeding by the specialist Plutella xylostella was negatively correlated with resistance against larval feeding by the generalist Mamestra brassicae and with resistance against oviposition by P. xylostella when variation in resistance was examined within and among two Swedish and two Italian A. thaliana populations. The results suggest that negative correlations between resistance against different herbivores and different life-history stages of herbivores may contribute to the maintenance of genetic variation in resistance.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-23T15:22:35Z No. of bitstreams: 1 Cleia Gomes Vieira e Silva.pdf: 397357 bytes, checksum: 224e5b48f721843c7d8a272b57e0013f (MD5) / Made available in DSpace on 2016-11-23T15:22:35Z (GMT). No. of bitstreams: 1 Cleia Gomes Vieira e Silva.pdf: 397357 bytes, checksum: 224e5b48f721843c7d8a272b57e0013f (MD5) Previous issue date: 2007-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Plants constitute natural sources of insecticide substances and have been used by mankind since Antiquity. It is also known that medicinal plants present great quantities of secondary compounds such as alkaloids, terpens, flavonoids and steroids which promote high resistance to the onset of pests and diseases. The genus Croton, which is made up of species that occur naturally in the State of Pernambuco, where many of them are used in the popular medicine and characterize themselves by the production of essential oil, owns expressive relevance founded on their sources of fixed and volatile components with recognized biological activity in the treatment of various illnesses. The knowledge that medicinal plants present high resistance to the onset of diseases and pests has led us to investigate the potential insecticide of crude ethanolic extracts from different parts of plants of the genus Croton against Plutella xylostella L. and of the essential oil of the species C. grewioides against Zabrotes subfasciatus Boheman. All the investigated plants are native to the biome in Pernambuco with use in the popular medicine by the community where its occurrence is reported. The crude extracts were obtained through cold maceration, ethanol being used as solvent, from leaves and stalks of the species Croton jacobinensis Baill, C. micans Muell., C. rhamnifolius H.B.K and C. sellowii Baill. The essential oil, on the other hand, was obtainedthrough hydro-distillation from the leaves and stalk of C. grewioides. These extracts were diluted into previously determined concentrations by means of a pilot experiment and their activities were tested for the development and survival of Plutella xylostella L. To do so, with the aid of Potter’s Tower, eight-cm diameter cabbage disks, Brassica oleracea var. acephala L., were ground with different concentrations of the ethanolic extracts and offered to caterpillars confined into Petri’s dishes. Among the studied extracts, the ethanolic extract from leaves of C. rhamnifolium was the most toxic at the larval phase, followed by the ethanolic extract from the stalk of the same species, presenting CL50 of 14.95 and 42.40μg mL-1, respectively. The interference of the extract of C. rhamnifolius in the development of P. xylostella was also noticed. From the stalk and leaves of Croton grewioides Baill essential oils were extracted through hydro-distillation and then analyzed by GC/MS. This analysis revealed that both oils are made up of 22 compounds, in which the predominant chemical class was that of the phenylpropanoids, whose major representative was (E)-anetol (65.5% in the leaves and 47.8% in the stalk). The fumigant effect of both essential oils was assessed for the woodworm of beans, Z. subfasciatus, which presented itself as potential for the control of this pest. The essential oil of leaves presented itself about 3.4 times more effectivethan the essential oil from the stalk and the estimated values for the CL50 were 4.0 and 13.7 μg mL-1 of air, respectively. / As plantas constituem fontes naturais de substâncias inseticidas, e vêm sendo utilizadas pela humanidade desde a antiguidade. As plantas medicinais apresentam grandes quantidades de compostos secundários como alcalóides, terpenos, flavonóides e esteróides, que promovem alta resistência ao ataque de pragas e de doenças. O gênero Croton, que é constituído por espécies que ocorrem naturalmente no estado de Pernambuco, onde muitas delas são utilizadas na medicina popular. Estas plantas se caracterizam pela produção de óleo essencial e detém expressiva relevância alicerçada em suas fontes de componentes fixos e voláteis com reconhecida atividade biológica no tratamento de várias enfermidades. O conhecimento de que plantas medicinais apresentam alta resistência ao ataque de doenças e pragas motivou a investigação do potencial inseticida de extratos etanólicos brutos de diferentes partes de plantas do gênero Croton no controle de Plutella xylostella L. e do efeito fumigante de óleo s essenciais da espécie C. grewioides contra Zabrotes subfasciatus Boheman. Todas as plantas investigadas são nativas do bioma pernambucano com uso na medicina popular pela comunidade onde sua ocorrência é registrada. Os extratos brutos foram obtidos por maceração a frio, utilizando como solvente o etanol, a partir de folhas e caules das espécies Croton jacobinensis Baill, C. micans Muell., C.rhamnifolius H.B.K. e C. sellowii Baill. Já o óleo essencial foi obtido por hidrodestilação a partir de folhas e caule de C. grewioides. Os extratos obtidos foram diluídos em concentrações previamente determinadas mediante experimento piloto e tiveram suas atividades testadas sobre o desenvolvimento e sobrevivência de Plutella xylostella L. Para isto, com auxílio de torre de Potter, discos de oito cm de diâmetro de folhas de couve, Brassica oleracea var. acephala L., foram pulverizados com diferentes concentrações dos extratos etanólicos, e oferecidos às larvas confinadas em placas de Petri. Dentre os extratos estudados, o extrato etanólico de folhas de C. rhamnifolium foi o mais tóxico à fase larval, seguido do extrato etanólico de caule da mesma espécie, apresentando CL50 de 14,95 e 42,40μg mL-1, respectivamente. Observou-se ainda uma interferência do extrato de C. rhamnifolius no desenvolvimento de P. xylostella. O óleo essencial obtido a partir do caule e folhas de Croton grewioides Baill. foi analisado por CG/EM. Um total de 22 compostos foi identificado. A classe química predominante foi fenilpropanóide, cujo representante majoritário, o (E)-anetol apresentou percentual de 65,5% no óleo de folha, e 47,8% no óleo do caule. Bioensaio de fumigação foi realizado contra o caruncho do feijão Z. subfasciatus. O óleo essencial de folhas foi cerca de 3,4 vezes mais tóxico eficaz do que o óleo essencial do caule cujos valores estimados para a CL50 foram 4,0 e 13,7 μgL-1 de ar, respectivamente.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T11:56:50Z No. of bitstreams: 1 Lilian Maria da Solidade Ribeiro.pdf: 1291994 bytes, checksum: 217ae867676a57b323ee75ec19d87a49 (MD5) / Made available in DSpace on 2016-11-28T11:56:50Z (GMT). No. of bitstreams: 1 Lilian Maria da Solidade Ribeiro.pdf: 1291994 bytes, checksum: 217ae867676a57b323ee75ec19d87a49 (MD5) Previous issue date: 2010-02-01 / The resistance of Plutella xylostella (L.) (Lepidoptera: Plutellidae) has been attributed to many mechanisms as alterations in cell membrane receptors on midgut and the immune response to Bacillus thuringiensis Berliner toxin. The research tested the possibility that after expositions to Bt formulations, insects from a susceptible population (SP) and a resistant population (RP) presented qualitative and quantitative differentiated alterations of hemocytes and nitric oxide levels in hemolymph, histopathological and histochemical differenced alterations in midgut and that RP presented capacity of recovery midgut. SP and RP were exposed to Dipel® 1,35 mg/L (SP), 64,93mg/L (RP); XenTari® 5,17 mg/L (SP), 236,24 mg/L (RP) plus witness had hemolymph collected in intervals of 1, 6 and 12 h for total and differential counting of hemocytes and quantification of nitric oxide. The midgut was collected in the intervals: 0, 1, 6, 12 h. The regenerative cells quantification was made through the ImageLab 2000 program. In spite of RP had showed less number of hemocytes, it exhibited greater quantity of plasmatocytes, prohemocytes and spherulocytes, this can be related to resistance. Dipel® was effective in reduction of total numbers of hemocytes of SP and RP, while XenTari® changed significantly the differential counting. The nitric oxide increased in both populations and it not differed between the insecticides, indicating the no participation of it in the resistance. The insecticides induced alterations in different intensities on midgut in SP and RP, Dipel® showed to be more aggressive independently of population, taking to degeneration of epithelium. The presence of spherites covering the epithelial lamina, the hypertrophy of columnar cells and mucus abundance can be involved in midgut preservation in larvae of resistant population, however these features were not sufficient to avoid the degeneration of epithelium or induce the hyperplasia of regenerative cells. / A resistência de Plutella xylostella (L.) (Lepidoptera: Plutellidae) pode ser atribuída a vários mecanismos como alterações nos receptores de membrana celular no mesêntero e a resposta imune às toxinas do Bacillus thuringiensis Berliner. A pesquisa testou as hipóteses de que após exposição a formulações Bt: população suscetível (PS) e população resistente (PR) da traça apresentam alterações quantitativas e qualitativas diferenciadas dos hemócitos e dos níveis de óxido nítrico na hemolinfa, alterações histopatológicas e histoquímicas diferenciadas no mesêntero e de que PR apresenta capacidade de recuperação do mesêntero. PS e PR expostas ao Dipel® 1,35 mg/L (PS), 64,93mg/L (PR); XenTari® 5,17 mg/L (PS), 236,24 mg/L (PR), além da testemunha, tiveram hemolinfa coletada nos intervalos de 1, 6 e 12 h para contagem total e diferencial dos hemócitos e quantificação de óxido nítrico. O mesêntero foi coletado nosintervalos: 0, 1, 6 e 12 h. A quantificação das células regenerativas foi efetuada através do programa ImageLab 2000. Apesar de PR ter apresentado menor número de hemócitos, exibiu maior quantidade de plasmatócitos, prohemócitos e esferulócitos, podendo isto estar relacionado à resistência. Dipel® foi efetivo na redução do número total de hemócitos das PS e PR, enquanto que o XenTari® alterou significativamente a contagem diferencial. O óxido nítrico aumentou emambas as populações, não diferindo entre os inseticidas, indicando a não participação deste na resistência. Os inseticidas ocasionaram alterações, de intensidades diferentes, no mesêntero das PS e PR, Dipel® mostrou ser mais agressivo independente da população, levando a degeneração do epitélio. A presença de esferites revestindo a lâmina epitelial, a hipertrofia das células colunares e a riqueza de muco podem estar envolvidas na preservação do mesêntero em larvas da população resistente, porém essas características não foram suficientes para impedir a degeneração do epitélio ou induzir a hiperplasia das células regenerativas.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-30T14:00:30Z No. of bitstreams: 1 Vando Miossi Rondelli.pdf: 326776 bytes, checksum: dcb87ae6833a0da7386f1f749cabbc4a (MD5) / Made available in DSpace on 2016-11-30T14:00:30Z (GMT). No. of bitstreams: 1 Vando Miossi Rondelli.pdf: 326776 bytes, checksum: dcb87ae6833a0da7386f1f749cabbc4a (MD5) Previous issue date: 2010-02-01 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The diamondback moth (DBM), Plutella xylostella (L.) (Lep.: Plutellidae) is considered the most important pest of brassicas productive systems. Due to the high use of pesticides for DBM control, alternative methods to be applied against DBM are necessary. The use of the enthomopathogenic fungus Beauveria bassiana (Bals.) Vuill. and vegetable oils present as promising alternatives to control DBM. Thus, 17 isolates of B. bassiana were studied aiming to select isolates to be used for DBM control. The commercial formulation Boveril® WP (isolate ESALQ-PL63) was also included in the bioassays. Among the evaluated isolates, the isolates CCA/UFES-4, 18, 31 e 35 were selected because they caused mortality confirmed for 2nd-instar larvae greater than 90%. The standard isolate ESALQ-447 and the commercial formulation (Boveril® WP) had similar results and were also selected. In addition, the isolates CCA/UFES-4, 18, 31, ESALQ-447 and Boveril® WP were considered efficient for DBM control based on the lethal concentrations LC50-values. The castor bean oil has its efficacy and stability evaluated, as its compatibility with B. bassiana upon P. xylostella as well. The castor bean oil 1-d old caused53.9% mortality for P. xylostella. The insecticidal activities, however, were unstable over timewhich requires further studies. The results also indicate compatibility between the oil of castor bean and B. bassiana. / A traça-das-crucíferas, Plutella xylostella (L.) (Lep.: Plutellidae) é considerada a principal praga no mundo nos sistemas produtivos de brássicas. Devido a grande utilização de agrotóxicos para o seu controle, métodos alternativos para o manejo dessa praga se fazem necessários, e o uso do fungo entomopatogênico Beauveria bassiana (Bals.) Vuill. e óleo vegetal apresentam-se como alternativas. Desta forma, 17 isolados desse fungo foram estudados objetivando selecionar isolados para ser utilizado no controle da traça-das-crucíferas. O formulado comercial Boveril® PM (isolado ESALQ-PL63) também foi incluído nos bioensaios. Entre os isolados avaliados, os isolados CCA/UFES-4, 18, 31 e 35 foram selecionados por causarem mortalidade confirmada de larvas do segundo instar superior a 90%. O isolado padrão ESALQ-447 e o formulado comercial (Boveril® PM) tiveram resultados semelhantes e também foram selecionados. Adicionalmente, os isolados CCA/UFES-4, 18, 31, ESALQ-447 e o Boveril® PM foram considerados eficientes para o controle da traça-das-crucíferas, mediante os resultados das estimativas da CL50. O óleo de mamona foi avaliado quanto a sua eficiência e estabilidade, como também a sua compatibilidadecom B. bassiana sobre P. xylostella. O óleo de mamona com 1 dia proporcionou mortalidade de 53,9% para P. xylostella. As atividades inseticidas, no entanto, foram instáveis ao longo dotempo, sendo necessários estudos adicionais. Os resultados também indicam compatibilidade entre o óleo de mamona e B. bassiana.

Conura torvina (Cresson) (Hymenoptera: Chalcididae) is a solitary pupal endoparasite of numerous insect species. In Brassica crops it acts as a parasite of Plutella xylostella (L.) (Lepidoptera: Plutellidae) and was found as a hyperparasite of Cotesia rubecula (Marshall) (Hymenoptera: Braconidae) and several other parasitoid species. Cotesia rubecula was introduced into Virginia in 1987 as a biological control agent for Pieris rapae (L.) (Lepidoptera: Pieridae), and because C. torvina was thought to have eliminated this population of C. rubecula, studies of C. torvina's reproductive biology and behavior were initiated. A study using plants laden with "trap hosts" to detect C. torvina activity in the spring indicated no activity until late June, but proved trap host sampling to be an efficient and effective method of monitoring C. torvina activity. Studies of C. torvina's ability to reproduce in C. rubecula pupae of different ages indicated that C. torvina can successfully parasitize pupae at all stages of development, but was most successful in young to middle aged pupae. Studies of C. torvina's host species preference indicated the larger host species such as P. xylostella were preferred. Equal numbers of P. xylostella and C. rubecula were parasitized, but a greater proportion of fertile eggs were laid in P. xylostella. Smaller host species were often ignored. Host dissection studies indicated that caged C. torvina were inefficient at host finding and oviposition. Superparasitism was common, but declined as the females gained oviposition experience. Experienced C. torvina produced an average of 8.25 progenies per day for a period of 12 days when provided with 13 P. xylostella hosts each day. Conura torvina produced up to 14 progenies a day when provided 3 26 hosts. Dissection of C. torvina ovaries indicated three ovarioles per ovary with a mean of 9.2 and maximum of 15 mature eggs per female. Host dissection indicated that a mean of 18 and maximum of 30 eggs could be laid per day. New eggs were produced as oviposition occurred. Significantly larger eggs were laid in P. xylostella than in C. rubecula, and significantly more eggs were laid in C. rubecula than in P. xylostella. From these data and data from earlier studies I concluded that C. torvina has a poor reproductive ability and its impact as a hyperparasite is limited to the summer months. This makes C. torvina an unlikely cause of C. rubecula's disappearance. / Ph. D.

No description available.