Thesis (Ph.D)--Mississippi State University. College of Veterinary Medicine. / Title from title screen. Includes bibliographical references.

As discussed in Chapter 1, although our understanding of the ecology and evolution of carnivorous plants has greatly improved in recent years, many fundamental questions remain unanswered. Unfortunately, at the present time, many carnivorous plants are increasingly threatened by anthropogenic activities. Indeed, over half of the carnivorous plant species assessed by the International Union for the Conservation of Nature (IUCN) are listed as `threatened', but the threats to carnivorous plants have not previously been quantified. In Chapter 2, I quantified the conservation threats to carnivorous plant taxa worldwide by searching peer-reviewed literature, and found data on the threats to 48 species of carnivorous plants from nine genera. The most common threat was habitat loss from agriculture, followed by the collection of wild plants, pollution, and natural systems modifications. As I found in Chapter 2, while agrochemical pollution is thought to be an important conservation threat to carnivorous plants, the effects of insecticides in particular on these taxa have not previously been quantified. Therefore in Chapter 3 I tested the effects of commercial and technical grades of three widely used insecticides (carbaryl, lambda-cyhalothrin, and malathion) on survival and the expression of traits associated with carnivory of pink sundews (Drosera capillaris) and Venus flytraps (Dionaea muscipula) using a combination of lab- and field-based experiments. Commercial grades were generally more harmful than technical grades under lab and field conditions, but all three insecticides were capable of causing negative effects on the plants within recommended application rates. Pink sundews appeared to be more susceptible to insecticides than Venus flytraps, perhaps because of larger numbers of digestive glands on the leaf surfaces. Given the effects observed, I suggest that the use of insecticides should be carefully managed in areas containing vulnerable carnivorous plant species. For Chapters 4 and 5, I explored the ecological role of carnivorous plants, specifically if they could compete with animals for shared prey resources. In Chapter 4 I characterized the ground-surface spider and arthropod assemblages of two mesic flatwood habitats in Florida, to resolve what the most likely animal competitor was for pink sundews. I identified 31 spider species from 27 genera in 12 families, with wolf spiders (Lycosidae) being the dominant spider family at both sites. Based on their abundance and the behavioral traits they exhibited, I determined that the funnel-web-building wolf spider Sosippus floridanus was the most likely potential competitor with pink sundews. Collembola and Formicidae were the most abundant arthropod taxa present, but ground-surface spiders were not strongly associated with any typical prey groups, suggesting that environmental factors might also be important in structuring this community. Subsequently, in Chapter 5 I examined the potential for competition between carnivorous plants and animals by studying dietary and microhabitat overlap between pink sundews and wolf spiders in the field, and by conducting a lab experiment examining the effects of wolf spiders on sundew fitness. In the field, I found that sundews and spiders had high dietary overlap with each other and with the available arthropod prey. Associations between sundews and spiders depended on spatial-scale: sundews and spiders were both found more frequently in quadrats with more abundant prey, but within quadrats spiders constructed larger webs and located them further away from sundews as the total sundew trapping area increased. Spiders also constructed larger webs when fewer prey were available. In the lab, my experiment revealed that spiders can significantly reduce sundew fitness. All of these results suggest that members of the plant and animal kingdoms can and do compete. These findings provided inspiration for Chapter 6, where I explored if phylogenetic distance was a good predictor of the strength of competition between taxa, using a meta-analytical approach. I collected data from studies published from 1998-2008 in eight ecology journals using the keyword `interspecific competition', gathering a total of 191 effect sizes. I found no significant relationship between phylogenetic distance and the strength of competition, contrary to the long-standing assumption that it should be greatest in strength between closely related species. However, these findings could presently be limited by publication bias, and I suggest several directions for future research.

No description available.

Metarhizium anisoplia var. acridum, a gyphomycetous fungus registered worldwide for grasshopper and locust control, is currently under consideration as a worldwide for grasshopper and locust control, is currently under consideration as a potential alternative to chemical insecticides for grasshopper control in Canada. Research in this thesis has contributed data required for the registration of biological control agents in Canada. A diagnostic PCR assay was developed for the specific detection of M. anisopliae var. acridum DNA. The assay was highly sensitive and effective for the detection of fungal DNA in infected grasshoppers. A survey of southern Alberta soils conducted in the spring of 2004 revealed the presence of Metarhizium spp. at low natural incidennce. Two indigenous isolates demonstrated pathogenicity when bioassayed against laboratory-reared and field collected grasshoppers. One of the isolates demonstrated virulence comparable to a commercial isolate. An analysis of historical weather data revealed that summer weather in the Prairie provinces should not preclude the efficacy of M. anisopliae var. acridum under local conditions. / xv, 127 leaves : ill. (some col.) ; 28 cm.

Field and laboratory investigations were conducted in Burkina Faso to diagnose the causes of severe outbreaks of Bemisia tabaci populations and gênerai failures of chemical control against this pest in cotton. / Field and laboratory investigations were conducted in Burkina Faso to diagnose the causes of severe outbreaks of Bemisia tabaci populations and general failures of chemical control against this pest in cotton. The research efforts were oriented in the following three areas: I) the susceptibility of B. tabaci populations and its parasitoids to cotton insecticides; I) the susceptibility of B. tabaci populations and its parasitoids to cotton insecticides, a) conventional insecticides, b) novel insecticides; II) the relative abundance of B. tabaci and its parasitoids in the field; III) the biological activities of some botanical extracts as alternative insecticides against the pest.

No description available.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Thesis (M.S.)--Michigan State University. Dept. of Entomology, 2006. / Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 106-117). Also issued in print.

This work was performed to test the effect of aqueous extract of Cabralea canjerana subsp. polytricha (Meliaceae) in the control of Brevycorine brassicae (Hemiptera: Aphididae) and Ascia monuste orseis (Lepidoptera: Pieridae). Extract of leaves, fruits and seeds of 3, 5 and 10% were obtained through infusion of dry and triturated material in distilled water filtered after 24 hours. The effect of the extracts was tested in the survival of B. brassicae and the viability, larval and pupal weight and repellent/antifeedant activity of A. monuste orseis. Extract of 3 and 5% did not demonstrated insecticide action on B. brassicae. However, extract of 10% of concentration was able to control this insect in laboratory conditions. The larvae of A. monuste orseis demonstrated low viability when treated with leaves immersed in the extracts, dying before completing four days of age, on average. The evaluation of the repellent/antifeedant effect of the extract indicates that, in tests with choice, the individuals tend to avoid leaves treated with seeds extracts. Differences in consumed area were only demonstrated in the tests using extract of 10%. However, cabbage leaves immersed in fruits and seeds extracts presented a lower consumed area. Tests without choice indicate that when extract of 5 and 10% were used, cabbage leaves consumption was reduced. / Este trabalho teve como objetivo testar o efeito de extratos aquosos de Cabralea canjerana subsp. polytricha (Meliaceae) no controle de Brevicoryne brassicae (Hemiptera: Aphididae) e Ascia monuste orseis (Lepidoptera: Pieridae). Extratos de folhas, frutos e sementes a 3, 5 e 10% foram obtidos por infusão de material seco triturado em água destilada, filtrados após 24h. O efeito dos extratos foi testado na sobrevivência de B. brassicae e viabilidade, peso larval e pupal e atividade repelente/deterrente em A. monuste orseis. Extratos a 3 e 5% não demonstraram ação inseticida sobre B. brassicae. Todavia, extratos a 10% de concentração realizaram controle deste inseto em condições de laboratório. As larvas de A. monuste orseis demonstraram baixa viabilidade, quando alimentadas com porções foliares tratadas, não ultrapassando os quatro dias de idade, em média. A avaliação do efeito repelente/deterrente dos extratos indicou que, em testes com chance de escolha, os indivíduos tenderam a evitar folhas tratadas com extratos de sementes. Diferenças na área consumida só foram demonstradas em testes com extratos a 10%. Todavia, folhas de couve imersas em extratos de frutos e sementes apresentaram uma menor área consumida. Testes sem chance de escolha indicaram que quando extratos a 5 e 10% foram usados, o consumo das folhas foi reduzido. / Mestre em Ecologia e Conservação de Recursos Naturais

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-18Bitstream added on 2014-06-13T18:34:57Z : No. of bitstreams: 1 fanela_tlm_me_botfca.pdf: 796585 bytes, checksum: 6e00fd8810280907bea817832ec52f7d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A mosca-branca, Bemisia tabaci (Gennadius) biótipo B, é uma praga de grande importância na cultura do tomateiro em todos os sistemas de cultivo. O controle é feito, comumente, utilizando-se inseticidas sintéticos; entretanto, devido aos conhecidos problemas socioambientais que essa tática apresenta, justifica-se o desenvolvimento de métodos alternativos de controle. O presente trabalho teve por objetivo avaliar o efeito de extratos aquosos a 3% e óleos essenciais em diferentes concentrações provenientes de diferentes espécies vegetais (Azadiracta indica A. Juss, Chenopodium ambrosioides L., Mentha pulegium L., Mansoa alliacea (Lam.) A. Gentry, Piper aduncum L., Piper callosum Ruiz & Pav., Pelargonium graveolens L'Her, Plectranthus neochilus Schltr., Ruta graveolens L., Trichilia casaretti C. DC., Toona ciliata M. Roemer, Trichilia pallida Swartz e Vitex agnus-castus L.) sobre B. tabaci biótipo B em tomateiro. Para tanto, foram realizados testes avaliando o efeito dos extratos aquosos e óleos essenciais no comportamento dos insetos adultos (aproximação e oviposição) e atividade inseticida (mortalidade) em condições de laboratório. Constatou-se que o extrato aquoso de T. ciliata diminuiu o número de insetos adultos e ovos em folíolos de tomateiro. O extrato aquoso de P. aduncum apresentou o maior efeito ovicida (eficiência de controle de 78,41%) e o extrato de T. pallida causou a maior mortalidade de ninfas e adultos de mosca-branca (eficiências de controle de 67,95% e 72,80%, respectivamente). O óleo essencial de P. callosum foi o mais eficiente na redução de adultos e ovos de mosca-branca nos folíolos de tomateiro. Quanto ao efeito fumigante, o óleo essencial de M. alliacea foi o mais eficaz, tanto para ninfas como... / Bemisia tabaci (Genn.) biotype B is an important pest of tomato plants. In addition to the direct damage by sucking sap, the insect is also a vector of phytovirus. Aiming to evaluate the possible alternative methods of control this pest tests were conducted under laboratory conditions using aqueous extracts at 3% (weight/volume) and essential oils in different concentrations, evaluating the effect on behavior of adult insects (approach and oviposition) and insecticidal activity (mortality), from thirteen different plant species (Azadiracta indica A. Juss, Chenopodium ambrosioides L., Mentha pulegium L., Mansoa alliacea (Lam.) A. Gentry, Piper aduncum L., Piper callosum Ruiz & Pav., Pelargonium graveolens L'Her, Plectranthus neochilus Schltr., Ruta graveolens L., Trichilia casaretti C. DC., Toona ciliata M. Roemer, Trichilia pallida Swartz e Vitex agnus-castus L.) in tomato. The results showed that extract from leaves of T. ciliata was the most effective in reducing adults and eggs of whitefly on tomato leaflets. P. aduncum extract was the most efficiency treatment in reducing the nymphs hatched (control efficiency of 78.41%). T. pallida extract was more efficient by causing higher mortality rate against the insect with control efficiency of 67.95% (nymphs) and 72.80% (adults). The essential oil of P. callosum was the most effective in reducing adults and eggs of whitefly on tomato leaflets. The essential oil of M. alliacea caused the highest mortality in nymphs and adults. For adults, LC50 after 6 hours was 0.07 μL/L of air and LT50 at the highest concentration was 1.98 hours. For nymphs, LC50 calculated after 72 hours fumigation was... (Complete abstract click electronic access below)