No Brasil, o bicudo da cana-de-açúcar, Sphenophorus levis Vaurie (Coleoptera: Curculionidae) tem se tornado nos últimos anos praga importante da cultura, principalmente no estado de São Paulo onde as perdas alcançam 30 ton/ha/ano e no Sul do estado de Minas Gerais. Isto devido à ausência de medidas preventivas para a disseminação e ao crescimento da área plantada, decorrente da alta demanda de álcool. Existem diversos métodos para o seu controle e um dos mais empregados são as iscas tóxicas; apenas impregnadas com o inseticida carbaril não existindo alternativas, o que pode favorecer a aparecimento de populações resistentes do inseto, dificultando o controle. Sendo assim, é evidente a necessidade de investigar outros inseticidas tão ou mais eficientes visando aumentar inclusive a eficiência das iscas utilizadas atualmente através da incorporação de substâncias mais atraentes. O presente trabalho foi realizado no Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da Escola Superior de Agricultura \"Luiz de Queiroz\", Universidade de São Paulo, e teve como objetivos avaliar a atração de adultos de S. levis por meio de olfatômetro \"Y\" a toletes de cana-de-açúcar com e sem melaço a 10% e casca de abacaxi, em diferentes períodos de fermentação (24, 48 e 72hs), horários (diurno e noturno) e sexos (machos e fêmeas) e estabelecer a relação entre os compostos emitidos pelos substratos, acetato de etila e etanol, por meio de cromatografia gasosa, com a atração dos insetos a cada substrato testado; assim como avaliar o efeito letal dos inseticidas cartap e tiametoxam em diferentes dosagens fornecidas através de iscas de cana-de-açúcar no laboratório é validá-los em campo, comparando-os com as capturas das iscas contendo carbaril. Os resultados do laboratório demonstraram que a mistura cana-de-açúcar com melaço fermentado por 24 horas, atraiu os insetos em até 90% e que a resposta dos insetos foi maior no horário diurno, sem diferenças estatísticas entre os sexos. Os inseticidas cartap e tiametoxam nas dosagens 2,0 g p.c/L de água e 0,6 gp.c/L de água respectivamente, ocasionaram níveis de mortalidade superiores a 80% no laboratório. No campo a mortalidade em iscas contendo cartap (2,0 g p.c/L) foi menor que as iscas contendo carbaril e tiametoxam (0,6 g p.c/L) as quais tiveram resultados semelhantes. O maior número de insetos capturados nas iscas tóxicas foi registrado aos 7 dias, nos dias subseqüentes as capturas diminuíram. / In Brazil, the sugarcane weevil, Sphenophorus levis Vaurie (Coleoptera: Curculionidae), has become a serious pest of sugarcane in recent years mainly in the states of São Paulo and south of Minas Gerais where losses caused by this pest surpasses 30 ton/ha/year. This is due to lack of preventive measures for its dissemination and increase in the area planted with sugarcane as a result of high alcohol demand. There are several methods for its control and one of the most utilized methods are toxic baits impregnated with the insecticide carbaryl with no alternatives which could favor the selection of resistant populations of this pest, making control difficult. Therefore, it is necessary to investigate other insecticides including improving the efficiency of baits that are in current use through incorporation of more attractive substances. The present study was realized in the department of Entomology, Plant pathology and Agriculture Zoology of Escola Superior de Agricultura \"Luiz de Queiroz\", University of São Paulo, and had the objective to evaluate the attraction of the adults of S. levis through \"Y\" olfactometer to sugarcane nodes with and without 10% molasses and peelings of pineapple, in different fermentation periods (24, 48 e 72hs), times of the day (diurnal and nocturnal) and sexes (males and females) and to establish the relationship between the compounds emitted by substrates, ethyl acetate and ethanol by use of gas chromatography, with the attraction of insects by each substrate tested, as well as to evaluate the lethal effect of insecticides, cartap and thiametoxan in different doses delivered through sugarcane baits in the laboratory and field validation compared with carbaryl baits. The laboratory results demonstrates that a mixture of sugarcane with molasses fermented for 24 hours, attracted up to 90% of the insects and the insect response was higher during the day without statistical difference between the sexes. The insecticides cartap and thiametoxan at doses 2,0 g p.c/L and 0,6 gp.c/L of water respectively, caused mortality levels higher than 80% in the laboratory. In the field, baits containing cartap (2,0 g p.c/L) captured less insects than those with carbaryl and thiametoxan (0,6 g p.c/L) which had similar results. The highest number of captured insects in toxic baits was registered for 7 days and this diminished in subsequent days.

A utilização de plantas com ação inseticida tem sido considerada uma alternativa promissora no manejo integrado de pragas, apresentando diversas vantagens em relação aos atuais métodos de controle. Nos últimos anos no Brasil, uma série de estudos tem demonstrado que os produtos derivados de plantas apresentam bioatividade contra insetos. Assim, a identificação e a descrição dos compostos químicos responsáveis por essa bioatividade é fundamental, uma vez que tais compostos podem servir como modelos para a síntese de novos inseticidas sintéticos com estrutura química análoga à dos naturais, principalmente aqueles que apresentem mecanismos de ação diferentes dos produtos já registrados. Portanto, no presente estudo, foi realizada uma triagem com 17 extratos etanólicos provenientes de 9 espécies de Solanaceae para avaliar a bioatividade deles sobre o gorgulho-do-milho, Sitophilus zeamais Mots. (Coleoptera: Curculionidae). O extrato etanólico de folhas de Brugmansia suaveolens (Willd.) Bercht. & J. Presl foi o melhor entre todos, sendo as concentrações letais necessárias para matar 50 e 90% da população (CL50 e CL90) iguais a 2.231 mg kg-1 e 5.859 mg kg-1, respectivamente, e o tempo letal médio (TL50), usando a CL90, foi 99,78 h. Dessa forma, ele foi selecionado para uma série de fracionamentos químicos biomonitorados com ensaios toxicológicos para identificar compostos bioativos. Algumas das frações químicas obtidas a partir de B. suaveolens mataram mais de 50% dos adultos de S. zeamais, além de reduzirem a progênie F1 e, consequentemente, os danos nos grãos de milho. Essa bioatividade se deve, possivelmente, à presença de ácidos graxos e alcaloides. Por cromatografia líquida de alta pressão acoplada à espectrometria de massas de ultra resolução (UPLC-MS) da fração BSHex6F4, foram identificados compostos pertencentes ao grupo dos alcaloides. Por cromatografia gasosa acoplada à espectrometria de massas (GC-MS) das frações BSHex1-F3, BSHex1-F4 e BSHex1-F6 foram identificados derivados de ácidos graxos. Os resultados adquiridos no presente estudo demonstram o potencial de prospectar compostos inseticidas de espécies da família Solanaceae para proteger grãos de milho armazenado contra os danos causados por S. zeamais. / The use of plants with insecticidal action has been considered a promising alternative in the integrated pest managment, showing several advantages over current control methods. In recent years in Brasil, a number of studies have shown that plant-derived products have bioactivity against insects. Thus, the identification and description of the chemical compounds responsible for this bioactivity is fundamental, since such compounds can be used as models for development of new synthetic insecticides with chemical structure analogous to the natural ones, mostly those that present different mode of action of those currently registred. Therefore, in the present study, a screening was performed with 17 ethanolic extracts from 9 Solanaceae species to evaluate their bioactivity on the maize weevil Sitophilus zeamais Mots. (Coleoptera: Curculionidae) on stored grain corn. The ethanolic extract from the leaves of Brugmansia suaveolens (Willd.) Bercht. & J. Presl was the most efficient among all, presenting the lethal concentrations to kill 50 and 90% of the population (LC50 and LC90) equal to 2,231 mg kg-1 and 5,859 mg kg-1, respectively, and the mean lethal time (LT50), using the LC90, of 99.78 h. Therefore, this extract was selected to continue the biomonitoring chemical fractions with toxicological bioassays to identify bioactive compounds. Some of the chemical fractions obtained from B. suaveolens extract killed more than 50% of the adults of S. zeamais, besides reducing the progeny F1 and, consequently, the damages in the corn grains. This bioactivity is possibly due to the presence of fatty acids and alkaloids. An ultra performance liquid chromatography coupled to mass spectrometry (UPLC-MS) analysis was performed with the BSHex6-F4 fraction and alkaloids derivatives compounds were identified. A gas chromatography coupled to mass spectrometry (GC-MS) analysis was performed with the BSHex1-F3, BSHex1-F4 and BSHex1-F6 fractions and fatty acids derivatives were identified. The results obtained in the present study demonstrate the potential to prospect insecticidal compounds of Solanaceae family species to protect corn stored grains against damage caused by S. zeamais.

Sphenophorus levis (Coleoptera: Curculionidae) é uma das principais pragas de importância econômica na cana-de-açúcar. Seu ataque pode causar a morte da planta, promovendo falhas na rebrota e dependendo do nível de infestação, inviabilizar novos cortes. Além disso, é considerado um inseto de difícil manejo. Dentre as razões, destacam-se o hábito críptico de suas larvas, que se alimentam no interior do colmo da cana, e dos adultos, que permanecem boa parte de seu tempo abaixo da palhada sobre o solo. Por esta razão, os métodos tradicionais de controle, como os agroquímicos têm sido pouco eficientes. Neste sentido, a busca por novos conhecimentos e novas estratégias para o manejo desta praga tem se tornado frequente. Assim, o objetivo principal deste trabalho foi o de reinvestigar o feromônio de S. levis, visando a possível existência de novos compostos químicos na sua composição. Além disso, foram estudados ainda a morfologia e morfometria de S. levis, visando uma ágil e fácil separação por sexo nesta espécie, e uma amostragem populacional das formas biológicas de S. levis em campo, ao longo de uma safra, tendo em vista o manejo desta praga. As fêmeas apresentaram maior tamanho corporal que os machos, porém, houve sobreposição entre o tamanho mínimo da fêmea e máximo do macho, comprometendo uma distinção pelo tamanho. A separação dos sexos em S. levis pode ser feita observando-se a parte ventral do abdome, com os machos apresentando toda a região pilosa e as fêmeas somente com pelos na região apical. Uma maior concavidade presente no final do abdome dos machos, também pode ser utilizada como um parâmetro auxiliar nesta separação. Observando-se a flutuação populacional das diferentes fases biológicas de S. levis, por meio de trincheiras, verificou-se que as larvas ocorrem praticamente durante todos os meses do ano, enquanto que pupas e adultos recém emergidos, em menos da metade das amostras. O pico populacional de larvas, pupas e adultos recém emergidos ocorreu em outubro. Para os adultos, a amostragem por meio de iscas indicou que o pico de maior intensidade foi em dezembro. Na etapa de reinvestigação do feromônio de agregação de S. levis, foram obtidas respostas positivas nas antenas de machos e fêmeas para três compostos químicos. Um destes compostos foi o álcool 2-metil-4-octanol, já identificado anteriormente por Zarbin et al. (2003). Os outros dois, são novos compostos denominados 2,3-butanodiol diacetil (2,3 diacetilbutano) e meso 2,3 butanodiol diacetil (meso 2,3 diacetilbutano). Os três compostos sintéticos foram testados em GC-EAG, porém ainda sem uma resposta conclusiva. Novos testes necessitam ainda ser conduzidos para elucidar a composição química do feromônio de agregação de S. levis. / Sphenophorus levis (Coleoptera: Curculionidae) is one of the main pests of economic importance in sugarcane in Brazil. The attack can result plant death promoting the regrowth and failures depending on the level of infestation, derail further cuts. S. levis is a hard management pest. Among the reasons, it highlights the cryptic habits of larva, which feed inside the sugarcane stalk, and adults live in the soil surface, above of straw. Due to this, the traditional control methods such as agrochemicals have been inefficient. The search for new knowledge and new strategies for the management of this pest has become frequent. Thus, the main objective of this work was to reinvestigate the S. levis pheromone, aiming the possible existence of new chemical compounds in its composition. Beside that, this study aimed to morphometric and morphological comparison between males and females, seeking sex separation in a fast and effective manner. Moreover, population sample of S. levis in field was performed, aiming at an improvement in planning of the management of this pest. Females of S. levis have a greater body size than males; however this parameter cannot be used as a sex indicator, because there was overlap between the minimum and maximum body sizes of females and males respectively. S. levis sex separation can be carried observing abdomen ventral side, where males present hairy venter and females just a tuft in the apical region, and by a greater concavity of the end of the abdomen in males. The fluctuation of S. levis biological stages through trenches, it was found that the larvae occurs during almost all months of the year, while pupae and recently emerged adults in less than half of the samples. The population peak for larvae, pupae and recently emerged adults was in October. For adults, the sampling through baits indicated that the peak intensity was higher in December. Then, in the reinvestigate the S. levis pheromone, natural extracts from males showed responses of antennas of males and females of the species for three chemical compounds. One of these compounds was the alcohol 2-methyl-4-octanol, previously identified by Zarbin et al. (2003). The other two are new compounds, called 2.3-butanediol diacetil (2.3 diacetilbutano) and meso 2.3 butanediol diacetyl (meso 2.3 diacetilbutano). The three synthetic compounds were tested in GC-EAG, but there is still no conclusive answer. New tests still need to be conducted to elucidate the chemical composition of S. levis aggregation pheromone.

Este trabalho foi realizado com o objetivo de avaliar a influência do pó e do extrato aquoso de C. ambrosioides sobre o gorgulho-do-milho, S. zeamais. As plantas de C. ambrosioides foram cultivadas na área experimental do Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da ESALQ/USP. Foram obtidos pós de folhas, ramos, frutos e da planta inteira (com frutos), quando a planta apresentava-se no estágio de frutificação. Os insetos utilizados nos ensaios foram obtidos de criação mantida em grãos de trigo. Avaliou-se o efeito do pó das diferentes estruturas vegetais e da planta inteira (com frutos) sobre o comportamento (atratividade e/ou repelência), atividade inseticida sobre a fase imatura e adultos, e o poder inseticida residual, com o pó separado e em contato com grãos de trigo. Avaliou-se também a atividade inseticida do extrato aquoso das diferentes estruturas e da planta inteira (com frutos) sobre a fase imatura e adultos de S. zeamais. De acordo com os resultados obtidos concluiu-se que: a) pós de frutos, ramos e folhas de C. ambrosioides não apresentam repelência para adultos de S. zeamais; b) pós obtidos de ramos e folhas não apresentam atividade inseticida sobre adultos de S. zeamais; c) os compostos com atividade inseticida estão presentes nos frutos de C. ambrosioides; d) pós de frutos apresentam efeito inseticida residual contra adultos de S. zeamais por no máximo 5 dias; e) pós de frutos e da planta inteira (com frutos), aplicados após 15 dias da infestação inicial, possuem efeito inseticida sobre a fase imatura de S. zeamais; f) os extratos aquosos não afetam a sobrevivência e a emergência de adultos de S. zeamais. / This work deals with the influence of the powder and aqueous extracts of C. ambrosioides on the maize weevil, S. zeamais. The powders tested were obtained from leaves, branches, fruits and the whole plant (with fruits), when the plant was in the fructification period. The insects were obtained from a population reared on wheat grains. The effect of the powders from the different vegetal structures and from the whole plant (with fruits) was evaluated concerning the insect behavior (attractiveness and/or repellence), insecticide activity on the immature and adult phases, and the insecticide residual power on the adult phase, with the powder alone and mixed with wheat grains. The insecticide activity of the aqueous extract from the different structures and from the whole plant (with fruits) was evaluated on immature and adult S. zeamais. The results were as follows: a) powders from fruits, branches and leaves of C. ambrosioides are not repellent to S. zeamais adults; b) powders from branches and leaves do not present insecticide activity against S. zeamais adults; c) the compounds with insecticide activity are present in the C. ambrosioides fruits; d) powders from fruits present insecticide residual effect against S. zeamais adults for a period up to 5 days; e) powders from fruits and from the whole plant (with fruits), applied 15 days after initial infestation, present insecticide effect on S. zeamais immature phase; f) the aqueous extracts do not affect the survival and the adult emergence of S. zeamais.

Some aspects of the presence of systemic endophytic fungi in agriculturally important New Zealand grasses were studied in relation to plant breeding. Seedling resistance to adult Argentine stem weevil feeding in perennial ryegrass, Italian ryegrass and tall fescue was found to be related to the presence of their respective Acremonium endophytes in the seed rather than to plant genetic resistance. In addition a study of perennial ryegrass revealed that this resistance was independent of endophyte viability. The seedling resistance conferred by the endophyte of Italian ryegrass was found to be beneficial for field establishment. This endophyte differs from that in perennial ryegrass and tall fescue in that it does not confer resistance to Argentine stem weevil on mature plants, but only on seedlings. The extent of plant genetic seedling tolerance to adult Argentine stem weevil feeding was limited to broad inter-specific differences, with tall fescue more tolerant than perennial ryegrass and both of these more tolerant than Italian ryegrass. This ranking corresponds with previous observations on feeding preference on mature plants. A study of factors affecting the concentration of endophyte mycelia in infected seed of perennial ryegrass revealed that plant genetic factors had little effect. The major factors studied were: 1) the endophyte concentration in the maternal parent plant directly influenced the endophyte concentration in the seed. 2) nitrogen fertilizer applications to a seed crop reduced the concentration of mycelia in the seed, with earlier applications having a greater effect. 3) application of the fungicide propiconazole (Tilt) to a seed crop reduced the endophyte concentration in the seed. 4) the endophyte concentration in the seed was found to directly influence the endophyte concentration in seedlings, six month old plants and that of seed harvested from a first year seed crop. As there have been no previous reports of tetraploid perennial ryegrass cultivars with endophyte an experiment was conducted to determine if these could be developed by the standard procedure of colchicine treatment. The results revealed that endophyte was retained following colchicine treatment.

Studies of secondary seed dispersal by small mammals have largely been focused on the interaction between nut-bearing tree species and sciurid rodents such as squirrels, and on heteromyid rodents in the southwestern United States. However, there is now evidence that wind-dispersed tree species such as pines also undergo a process of secondary seed dispersal, where animals redistribute (cache) seeds that have already fallen to the ground, often in microhabitats more suitable for successful seed germination. In Florida sandhill, where fire suppression has threatened wind-dispersed longleaf pine ( Pinus palustris) by encouraging the encroachment of hardwoods such as sand live oak ( Quercus geminata), secondary seed dispersal may be an important factor in determining community composition and persistence of longleaf pine systems. Using a combination of seed depots and seed predator exclosures, I looked at both longleaf pine and sand live oak in terms of whether small animals such as squirrels ( Sciurus carolinensis) and cotton mice ( Peromyscus gossypinus) cache the seeds, and where the seeds of these two tree species best germinate. Since sand live oak acorns are prone to infestation by weevils ( Curculio spp.), I also examined whether nut condition affects acorn germination potential. I found that longleaf pine seeds are cached by small mammals to a small degree. While these seeds are not moved great distances from where they originate, they are often redistributed into microhabitats that promote successful seed germination. Caging experiments indicated that seeds were most likely to germinate when buried in open areas between adult trees, and to some degree, under shrub cover. On the other hand, sand live oak acorns appear to face heavy predation by large seed predators such as raccoons ( Procyon lotor) and wild pigs (Sus scrofa). Those acorns that do escape predation, including weevil-infested acorns, may provide an opportunity for seedling establishment. However, it appears that sand live oak depends heavily on vegetative sprouting for regeneration. This suggests that even in the absence of fire, longleaf pines in Florida sandhill are able to persist through secondary seed dispersal by small animals coupled with heavy seed predation on competing sand live oak.

Raps (Brassica napus L.) ist die bedeutendste Ölpflanze in Deutschland. Der Ertrag wird jährlich durch den Befall von Schädlingen bedroht. Zum Einsatz kommen im konventionellen Anbau verschiedene Insektizide. Der Befall mit Rapsstängelrüsslern (Ceutorhynchus napi GYLL.) kann bis zu 70 % Minderertrag zur Folge haben. Entscheidend für die Ausprägung des Schadens ist der Vorgang der Eiablage. Mit der Eiablage gibt das Weibchen ein Sekret ab, welches das Stängelmark schädigt und die charakteristischen Symptome hervorruft. Die Symptome sind Stauchung der Pflanzen, verdrehte und aufgeplatzte Stängel. Die Wunden können Eintrittspforten für pilzliche Erreger sein. Die Eier bzw. Larven, die im Stängel schlüpfen und sich vom Stängelmark ernähren, sind mit konventionellen Insektizidbehandlungen nicht erreichbar. Der Schaden durch erwachsene Tiere ist, abgesehen von der Eiablage, unerheblich. Im Hinblick auf die Biologie von Insekten sind die Temperatureinflüsse von außen maßgeblich. Für den Klimawandel wird eine Erwärmung für Niedersachsen vorhergesagt von 2°C für die nahe Zukunft und 4°C für den Zeitraum 2070 - 2100. Ziel dieser Studie war es mit verschiedenen Versuchen den Einfluss des Klimawandels auf die Schädling-Pflanzen Beziehung zu benennen. Dazu gehörte ein Feldversuch, der angesetzt wurde um die Ausprägung des Schadens durch den Rapsstängelrüssler an zwei verschiedenen Sorten zu vergleichen. Des Weiteren wurde untersucht wie sich eine erhöhte Bodentemperatur auf die Wirtspflanze und deren natürlicher Befall sowie das Schlupfen der erwachsenen Rüssler auswirkt. Im Labor wurden die Eiablage, die Lebensdauer und die Fertilität erwachsener Weibchen unter Einfluss unterschiedlicher Temperaturen beobachtet. Im Zuge des Klimawandels wird sich neben der Temperatur auch die Regenverteilung verändern. Deshalb befasste sich abschließend ein Versuch mit der Auswirkung von Trockenstress auf das Duftstoffspektrum von Raps. Die Ergebnisse dieser Studie sind ebenso vielfältig wie die Versuche selbst. Der Feldversuch hat keine Unterschiede des Befalls zwischen zwei Sorten gezeigt. Im Frühjahr bevorzugten die RSR die frühe Sorte und wechselten später auf die späte Sorte. Eindeutige Präferenzen waren nicht erkennbar. Indikatoren für die Ausprägung des Schadens kristallisierten sich nicht heraus. Innerhalb der Göttinger Bodenerwärmungsanlage wurde deutlich, dass die Erhöhung der Bodentemperatur auf 2°C und 4°C einen signifikanten Einfluss auf das Wachstum der Rapspflanzen hatte. Dies spiegelte sich auch in den Befallshäufigkeiten wieder. Die großen Pflanzen aus den erwärmten Bereichen wurden zur Eiablage der weiblichen Rapsstängelrüssler bevorzugt. In den erwärmten Bereichen wurden auch eine Woche früher 50 % des Schlupf der Erwachsenen erreicht. Die Eiablage ist temperaturabhängig. Je höher die Temperatur ist, desto signifikant mehr Eier werden gelegt. Es wurde ein Unterschied deutlich im Temperaturbedürfnis des Ei-Schlupf und in der Mortalitätsrate, ob die Temperatur gleichförmig oder wechselnd auf die Eier einwirkt. Die Fertilität und die Lebensdauer der erwachsenen Weibchen wurden nicht von der Temperatur beeinflusst. Trockenstress verändert das Duftstoffspektrum von Rapspflanzen. Es gibt Unterschiede in der Zusammensetzung der Duftstoffprofile und in der Intensität der abgegebenen Stoffe. Diese werden verändert durch den Trockenstress sowohl als auch durch den Fraß der erwachsenen Rüsslern. Diese Versuche waren der Anfang für die Erforschung des Klimawandels am Beispiel der Interaktion zwischen Raps und Rapsstängelrüsslers. Abschließend müssen weitere Versuche den komplexen Einfluss des Klimawandels auf dieser Beziehung klären.

Palms are ecologically important and charismatic trees of the tropics. They are important to the livelihood of local communities and are key resources for the frugivore community in tropical forests. These frugivores are in turn hunted by humans for food. This ecological connection between human, palms, and frugivores provides a unique setting to study how cultural and ecological components within this multitrophic interaction influences palm populations. In chapter 1, I explored the traditional and ecological knowledge behind the cultivation of palm-weevil larvae for food. I found the Joti people, cultivated two species of weevil-larvae differently, which also determined whether palms were logged before or after reproductive maturity. The cultivation of each weevil-larvae species therefore had a differential impact on palm populations. In chapter 2, I investigated how frugivores mediate interactions between two dominant and co-occuring palms in the Peruvian Amazonia-- Attalea phalerata and Astrocaryum murumuru. I found frugivores codispersed seeds of the two palm species, which contributed to aggregated spatial patterns of their juveniles. Spatial patterns suggested associations between heterospecific palms experienced lower density-dependent mortality than associations between conspecifics and this likely contributes to the coexistence of the two palm species in their early life-history. These findings highlight the importance of dispersers to species coexistence and suggest over-hunting can lead to shifts away from species codominance. In chapter 3, I examined the contribution of dispersal, distance-and density-dependent to spatial ecology of Attalea phalerata. Using microsatellite-based parentage analysis, I found high levels of seed movement mediated by frugivore dispersers. Despite this, I found dispersal limitation remains strong enough to cause spatial aggregation between offspring and parents. As individuals grew towards maturity, distance and density dependent mortality contributed to increasingly disaggregated patterns between older offspring cohorts of parents, non-parent adults, and siblings. These results provide a foundation for assessing the impacts of hunting on the spatial ecology of palm populations. In chapter 4, we characterized 14 microsatellite loci for A. phalerata that were used in the parentage analysis of chapter 3. These loci amplified reliably and were sufficiently polymorphic and will be useful for future studies addressing population-level questions for this species. / text

Strains of Bacillus thuringiensis active against Coleoptera were evaluated for toxicity against the adult stage of the carrot weevil, Listronotus oregonensis. Mortality and frass bioassays using a suitable semi-artificial diet showed strains A30, A429 and BTT to be highly toxic. Mortality persisted after initial exposure to the bacteria with the survivors not resuming normal feeding. Attempts to reisolate B. thuringiensis from the insects revealed B. thuringiensis-like organisms in the gut and in/on other structures. At the midgut pH of the insect (pH 8.0), the crystals of the toxic strains were significantly more soluble in vitro than were crystals of the less toxic strain A311. Proteolytic activation of the crystals with gut extracts yielded a protein band (66-67 kDa) for strains A30 and A429 which was similar to he apparent molecular weight of the toxin protein for BTT. Evidence suggests that the low toxicity of strain A311 might be due, in part, to the absence of the toxic moiety of the $ delta$-endotoxin.

The carrot weevil, Listronotus oregonensis LeConte (Coleoptera: Curculionidae), is an important pest of carrot in northeastern North America. The objective of this study was to determine the host selection stimuli used by two L. oregonensis parasitoids: the adult parasitoid Microctonus hyperodae Loan and the egg parasitoid Anaphes victus Huber. / In the first chapter, the response of M. hyperodae females to various odor components from potential hosts and host plants was tested with a Y-olfactometer. / In the second chapter, the effect of L. oregonensis adult sex, feces and movement on host selection behavior of M. hyperodae females was evaluated by quantifying L. oregonensis adult movement and various M. hyperodae female behaviors in an arena. / In the third chapter, the response of A. victus females to different L. oregonensis related odor components was evaluated using a filter paper of which half was moistened with odor components and the other half with water.