The time-varying survival rates of the carrot weevil, Listronotus oregonensis, were estimated by a new method. This method precluded the possibility of negative simulation survival rates. Analysis of carrot weevil population dynamics indicated that the egg mortality was density dependent with Anaphes sordidatus, an egg parasitoid, as a major density dependent factor. Larval mortality was less density dependent. Based on the mortality information, a simulation model for carrot weevil population dynamics was established. The simulation precision, evaluated by comparing simulated and observed egg and larval population dynamics, was satisfactory. Sensitivity analysis indicated that A. sordidatus had a large influence on carrot weevil population dynamics. The economic threshold for carrot weevil control in early carrots was 5 eggs/100 carrots at the peak population density. It ranged from 3.8 to 5.3 eggs/100 carrots in mid-season carrots depending on the selling price. A decision model showed that the best sowing date was after June 5 when risks were not considered. For risk aversion growers, sowing carrots between May 20 and May 31 was the best choice.

Bibliography: leaves A19-A23 / ix, 183, 23 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1982

The pea weevil (Bruchus pisorum L.) is the most significant pest of field pea (Pisum sativum L.) in Australia. The only available means for controlling pea weevil at the present time is with chemical pesticides. The aim of this study was to introgress natural pea weevil resistance, derived from the wild pea species, Pisum fulvum Sibth. & Sm. into cultivated field pea and devise strategies for screening for the resistance with breeding applications. Traditional breeding methods were used to transfer pea weevil resistance from P. fulvum accession ‘ATC113’ to cultivated field pea, cv. ‘Pennant’. Progeny derived from this population were examined for inheritance of pod and seed resistance. Seed resistance in F2 plants segregated in a ratio of 1:37:26 (resistant: mixed response: susceptible), indicating a trigenic mode of inheritance (1:63), with at least three major recessive genes controlling pea weevil resistance. Seed resistance was conserved over consecutive generations (F2 to F5) and was successfully transferred to populations crossed with a second adapted field pea variety‘Helena’. Pod resistance presented as a quantitative trait in the F2 population, but this resistance was not retained in subsequent generations. Amplified fragment length polymorphisms (AFLPs) were sought in the parents and in resistant and susceptible F3 plants. Restricted maximum likelihood (REML) analysis was used to identify 13 AFLP markers with a statistically significant association with pea weevil resistance and 23 with pea weevil susceptibility. Principal coordinate analysis (PCO) showed that the AFLP marker loci formed clusters in the PCO space, which could indicate the three proposed gene locations. Eight AFLP markers were cloned, sequenced and converted to sequence characterised amplified regions (SCAR). Two SCAR markers, SC47359 and SC47435 were polymorphic between the resistant and susceptible parents. Both markers co-segregated with the resistant lines and with 30-36% of susceptible lines. Plants which did not possess either band were highly susceptible. The other PCR products were either monomorphic between the resistant and susceptible parents or produced more than one band product. A range of phenotypic traits was measured in the F2 population derived from the hybridisation between P. fulvum and P. sativum and associations with pea weevil resistance were made. In the F2 population, pea weevil resistance was not correlated with any of the negative traits originating from the wild parent, such as increased basal branching, dark seed coat or small seed size, neither was resistance correlated with flower colour, flowering time or seeds per pod. Pea weevil resistance should therefore be transferable with minimal linkage drag. A convenient morphological marker, such as flower or seed colour was not identified in this study based on these results. Using principal component analysis (PCA) as a visual tool, resistant and semi-resistant plants in the F3 and ‘backcross’ introgression populations were identified with improved trait performance compared with the wild parent

Bibliography: leaves A19-A23.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2007. / Submitted to the African Centre for Crop Improvement. Full text also available online. Scroll down for electronic link.

Made available in DSpace on 2014-06-11T19:28:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-04Bitstream added on 2014-06-13T19:16:46Z : No. of bitstreams: 1 takada_hm_me_botfca.pdf: 587174 bytes, checksum: 68fcfeed820ef9c331817e76b2f9fab3 (MD5) / Com o objetivo de avaliar a patogenicidade e a virulência de fungos entomopatogênicos ao gorgulho aquático do arroz irrigado, Oryzophagus oryzae, foram testados 24 isolados de Metarhizium anisopliae e 2 de Beauveria bassiana. Os bioensaios foram realizados em condições controladas (26+1°C e 12 horas de fotofase). Nos testes para determinar a concentração adequada, a espécie M. anisopliae, isolado E9, apresentou maior patogenicidade quando comparado aos isolados de B. bassiana. A mortalidade confirmada, provocada pelo M. anisopliae, teve início no 4º dia, aumentando em seguida até estabilizar-se no 8º dia. Para a seleção dos isolados de M. anisopliae, adultos dos insetos foram inoculados com 1 mL de suspensão fúngica a 5x108 conídios/mL (1,6x104 conídios/mm2). Todos os isolados foram patogênicos ao inseto, sendo que a mortalidade variou entre 9,3 e 85,3 %. Os isolados de M. anisopliae mais patogênicos foram CB-103, CB-104, CB-233, E9 e CB-10. No teste de produção, os isolados CB-104, CB-233 e CB-103 foram superiores ao padrão E9, apresentando-se promissores para a utilização no controle de Oryzophagus oryzae. / Strains of Metarhizium anisopliae and Beauveria bassiana were evaluated concerning their pathogenicity and virulence for control of the rice water weevil, Oryzophagus oryzae. Bioassay conditions were 26+1ºC and 12 h. light. M. anisopliae (E9 strain) was been more pathogenic than two Beauveria bassiana strains (CB-66 and CB-74). For Metarhizium anisopliae (E9 strain), the mean mortality started at 4th day, increasing soon after until stabilize at 8 th day. A screening of M. anisopliae isolates was done inoculating adults of the insect with 1 mL of spore suspension containing 5x108 conídia/mL (1.6x104 conídia/mm2). All isolates were pathogenic to the insect, causing mortality between 9.3 and 85.3%. The most pathogenic isolates were CB-103, CB-104, CB-233, E9 and CB-10. These 6 isolates were evaluated concerning their spore production on cooked rice. The isolates CB-104, CB-233 and CB-103 afforded the highests spores production, significantly higher compared to E9, showing potential to be used for Oryzophagus oryzae control.

Made available in DSpace on 2015-03-26T13:30:41Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1958468 bytes, checksum: 99f699c55bb8c5be7f299e5a36245002 (MD5) Previous issue date: 2012-06-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Strategies of intraspecific competition among individuals can be considered as accommodative, in which there is coexistence and accommodation between competitors, or as confrontation where only one individual secures for itself the necessary resource for their survival and reproduction and the others die. Despite the importance of competition in life history strategies and behavior, there was any study conducted in Zabrotes subfasciatus. Given its importance as a pest of stored beans, this study aimed to evaluate the behavior of larval competition in Z. subfasciatus, as well as the population effects when larval competition in two distinct varieties of beans. In addition to the quantitative results of larval competition, which are commonly used to recognize the prevailing competition strategy, as the survival rate, larval developmental time, the proportion of females, males and females mass, total biomass, longevity and fecundity of females and mass of progeny; larval competition was observed directly by X-ray equipment digital high resolution. Image analysis allowed observing all stages of development from larva to adult, and the formation of the galleries during the larval period, showing the movement and the subsequent placement of individuals on the sides of the grain. This pattern of behavior becomes unquestionable the competition accommodative behavior of Z. subfasciatus. / Estratégias de competição intraespecífica podem ser consideradas como acomodativas, na qual há uma coexistência e acomodação entre competidores, ou como ativa ou por disputa, onde apenas um indivíduo assegura para si o recurso necessário para sua sobrevivência e reprodução e os demais morrem. Apesar da importância da competição em estratégias de história de vida e comportamental, nenhum estudo foi realizado em Zabrotes subfasciatus. Tendo em vista sua importância como praga de feijão armazenado, o presente trabalho objetivou avaliar o comportamento de competição larval em Z. subfasciatus, assim como os efeitos populacionais da estratégia de competição larval quando em duas variedades distintas de feijão. Além dos resultados quantitativos de competição larval, os quais normalmente são usados para reconhecer a estratégia de competição prevalecente, como a taxa de sobrevivência, tempo de desenvolvimento larval, proporção de fêmeas, massa de machos e fêmeas, biomassa total, longevidade e fecundidade de fêmeas, e massa da progênie; a competição larval foi observada diretamente através de equipamento de raios-X digital de alta resolução. A análise das imagens possibilitou observar todas as fases do desenvolvimento, desde a larva até o adulto, e a formação das galerias durante o período larval, evidenciando a movimentação e o posterior posicionamento dos indivíduos nas laterais do grão. Este padrão de comportamento torna inquestionável o comportamento de competição acomodativo de Z. subfasciatus.

The common bean Phaseolus vulgaris (Linnaeus, 1753) (Fabaceae) is a legume of great importance as a source of vegetal protein in Brazil. The insect damages bean grains and reduces its quality, affecting the appearance, palatability and acceptability by the consumers. The weevil Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae: Bruchinae) is one of the main pests of stored beans. The larvae of this insect open galleries in the bean grains, attacking the cotyledons and can completely destroy them. The methods currently used to control storage pest species are the purges and treatment with residual insecticides that are not always effective to exterminate the pests or to prevent reinfestation, and may result in problems such as insect resistance and animals and humans poisoning. This work aimed to evaluate the insecticidal activity of ten different plant species for the control of Z. subfasciatus. The weevil repellence, mortality, oviposition and adult emergence were evaluated in a non-choice test and the weevil oviposition and adult emergence were evaluated in a free-choice test. The plant species used were: Anadenanthera colubrina (Vell.) (cebil), Annona muricata L (soursop), Azadirachta indica A. Juss. (neem), Caesalpinia pyramidalis Tul. ( catingueira ), Chenopodium ambrosioides L. (Mexican tea), Cymbopogon citratus Stapf. (lemongrass), Cymbopogon sp. (citronella), Momordica charantia L. (bitter melon), Ricinus communis L. (castor oil plant) and Piper nigrum L. (Black pepper). For the repellence evaluation, a repellence index was established, using the t test for comparing the means. For the mortality and oviposition analysis, in the non-choice test, the F test was used and, when necessary, the means were compared by the Tukey´s test. Mortality, oviposition and adult emergence data were verified and, through a regression analysis, it could be concluded that C. ambrosioides and P. nigrum powders were highly toxic to the weevils, both causing 100% mortality after only four days of exposure. The powders from A. muricata, A. indica, C. pyramidalis, C. ambrosioides, Cymbopogon sp., C. citratus and P. nigrum were repellent to Z. subfasciatus adults and, except for C. pyramidalis, they little prefered oviposition in the free-choice test. In the non-choice oviposition test, there were no eggs on beans treated with C. ambrosioides and P. nigrum powders, and consequently, there was no adult emergence. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O feijão, Phaseolus vulgaris (Linnaeus, 1753) (Fabaceae), é a leguminosa de maior importância como fonte de proteína vegetal no Brasil. Os danos causados pelos insetos aos grãos de feijão reduzem a qualidade, afetando a aparência, palatabilidade e aceitabilidade pelo consumidor. O caruncho Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae: Bruchinae) é uma das principais pragas do feijão armazenado. As larvas desses insetos abrem galerias no grão de feijão, atacando os cotilédones e podendo destruí-los completamente. Os métodos atualmente utilizados para o controle de espécies de pragas em armazenamento são os expurgos e o tratamento com inseticidas residuais, que nem sempre são eficientes para controlar as pragas ou para evitar a reinfestação, podendo resultar em problemas de resistência dos insetos e intoxicações em animais e seres humanos. Este trabalho teve por objetivo avaliar a atividade inseticida de dez diferentes espécies vegetais para o controle de Z. subfasciatus. Foram avaliadas a mortalidade, oviposição e emergência, em teste sem chance de escolha, repelência e oviposição e emergência, em teste com chance de escolha. As plantas estudadas foram: Anadenanthera colubrina (Vell.) (angico), Annona muricata L (graviola), Azadirachta indica A. Juss. (nim), Caesalpinia pyramidalis Tul. (catingueira), Chenopodium ambrosioides L. (mastruz), Cymbopogon citratus Stapf. (capim-santo), Cymbopogon sp. (citronela), Momordica charantia L. (melão-de-são-caetano), Ricinus communis L. (mamona) e Piper nigrum L. (pimenta-do-reino). Para a avaliação da repelência, foi estabelecido um índice de repelência, e utilizado o teste t para comparação das médias. Na análise de mortalidade e oviposição em teste sem chance de escolha, foi usado o teste F e, quando necessário, as médias foram comparadas pelo teste de Tukey. Os dados de mortalidade, oviposição e emergência foram verificados e, pela análise de variância, pôde-se observar que o pó de C. ambrosioides é altamente tóxico aos insetos, assim como P. nigrum, causando a mortalidade de 100% dos insetos em apenas quatro dias de exposição. Os pós de A. muricata, A. indica, C. pyramidalis, C. ambrosioides, Cymbopogon sp., C. citratus e P. nigrum foram repelentes aos adultos de Z. subfasciatus e, com exceção de C. pyramidalis, também foram pouco preferidos para oviposição em teste com chance de escolha. Em teste de oviposição sem chance de escolha, os feijões tratados com os pós de C. ambrosioides e P. nigrum não foram ovipositados e, consequentemente, não houve emergência de adultos.

Rhynchophorus palmarum is the most harmful weevil pest of coconut palm due to its ability to find hosts from long distances and also to the direct and indirect losses it causes to the crop. Besides this, spores of the fungus that causes the stem bleeding disease have been found over R. palmarum body. Thus, the objective of this work was to evaluate the effect of the insecticide thiamethoxam and its association to the fungicide cyproconazole against R. palmarum larvae under laboratory conditions, aiming at the possible use of these products for managing R. palmarum and the fungal diseases associated to it. Newly-hatched and intermediate-instar larvae were fed with artificial diet containing insecticide or fungicide in the concentrations of 0.1%; 0.5%; 1.0% and 2.0%, and also the mixture of both. Larvae mortality on the treatments was assessed daily, during 48 hours. Means were subjected to analysis of variance and compared by Tukey’s test (P < 0.05). Regression analysis between the different product doses and larval mortality was also performed. Thiamethoxam caused mortality of 100 and 95% to newly-hatched and intermediate-instar larvae, respectively, statistically differing from cyproconazole (50 and 0%, respectively) and from the control (23.2 and 0%, respectively), but not differing from the two products mixture (100 and 92.5%, respectively). Such results point out that newly-hatched larvae are more sensitive than the intermediate-instar ones; that thiamethoxam in the doses here used is toxic to both newly-hatched and intermediate-instar larvae; that cyproconazole in the doses here used is toxic only to newly-hatched larvae; and that cyproconazole, when mixed to thiamethoxam does not improve its toxicity. Linear regression showed that thiamethoxam and its mixture with cyproconazole caused 100% mortality to newly-hatched larvae, and between 80 and 100% and between 90 and 100% to intermediate-instar larvae, respectively, in all tested concentrations. All concentrations were considered high. The thiamethoxam + cyproconazole mixture showed to be promising for the management of R. palmarum and the fungal diseases associated to it in coconut palms. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Rhynchophorus palmarum é, dentre os curculionídeos que atacam o coqueiro, o mais severo, pois além da capacidade de localizar sua planta hospedeira a longas distâncias, causa perdas diretas e indiretas à cultura. Além disso, esporos do fungo causador da doença resinose do coqueiro já foram encontrados no corpo de R. palmarum. Assim, o objetivo deste trabalho foi verificar em laboratório o efeito do inseticida tiametoxam, associado ao fungicida ciproconazol, sobre larvas de R. palmarum, visando a possibilidade de uso conjunto contra a praga e doenças fúngicas associadas a ela. Larvas de instares iniciais e de instares intermediários foram confinadas em dieta artificial contendo o inseticida e o fungicida isoladamente, nas concentrações de 0,1%; 0,5%; 1,0%; 2,0%, e também a mistura de ambos. A mortalidade das larvas nos tratamentos foi avaliada diariamente, durante 48 horas. As médias foram submetidas à análise de variância e comparadas entre si pelo teste de Tukey (P < 0,05). Também foi realizada a análise de regressão entre as diferentes doses dos produtos testados e a mortalidade das larvas. O tiametoxam causou mortalidade de 100 e 95% para larvas recém-eclodidas e intermediárias, respectivamente, diferindo estatisticamente do ciproconazol (50 e 0%, respectivamente) e da testemunha (23,2 e 0%, respectivamente), mas não diferindo da mistura dos dois produtos (100 e 92,5%, respectivamente). Tais resultados evidenciam que as larvas recém-eclodidas são mais sensíveis que as intermediárias; que o tiametoxam nas doses utilizadas é tóxico às larvas de ambas as idades; que o ciproconazol, nas doses utilizadas, é tóxico apenas para as larvas recém-eclodidas; e que o ciproconazol, quando adicionado ao tiametoxam, não potencializa o efeito deste. A regressão linear mostrou que tiametoxam e a mistura dos produtos causaram 100% de mortalidade às larvas recém-eclodidas, e entre 80 e 100% e entre 90 e 100% às larvas de tamanho intermediário, respectivamente, em todas as concentrações testadas, sendo estas consideradas altas para uso. A mistura de tiametoxam + ciproconazol se mostrou promissora para o manejo de R. palmarum e das doenças fúngicas associadas a ele em coqueiro.