The growing resistance of bacteria to traditional antibiotics promotes the interest in finding new substances for their production. Antimicrobial peptides have comparable effect to conventional antibiotics, but a different mechanism of action and they do not provoke bacterial resistance. These peptides were characterized in all forms of multicellular organisms. Hymenoptera venom contains many biologically active substances including antimicrobial peptides. For this reason, this thesis focuses on the acquisition of antimicrobial peptide sequences from selected species of bumblebees (Bombus terrestris, B. hortorum, B. hypnorum, B. pratorum, B. lucorum, B. lapidarius, B. humilis and B. bohemicus). The isolation from the venom glands was performed by high performance liquid chromatography with reversed phases. Subsequent analysis was performed using the methods of mass spectrometry, matrix-assisted laser desorption/ionization with time of flight analyzer and electrospray ionization connected with hybrid linear ion trap analyzer with orbitrap. The sequences for the found peptides were determined by tandem mass spectrometry methods "de novo" and Edman degradation. In this work we characterized 17 sequences of peptides extracted from bumblebee venom glands for which antimicrobial activity was determined...

The molecular mechanism of complementary sex determination in the haplodiploid organisms is poorly understood and has only been described in the honeybee Apis mellifera. In the haplodiploid system, males develop from unfertilized eggs and females from fertilized eggs. However, in some rare cases, diploid males develop from fertilized eggs. They can be distinguished from diploid and haploid males at the molecular level since they are heterozygous like females but are homozygous, like haploid males, at the sex determination locus. In this project, Osmia bicornis was chosen as the model organism, and the aim is to identify the complementary sex determination locus which should be homozygous in all diploid males. Bee nests were collected from the bees' natural habitat, and potential diploid males were identified. Data analysis of whole-genome sequencing on 17 potential diploid males was performed, which identified 80 candidate sex determination loci with 259 genes. Homologs of the Csd gene in A. mellifera were identified but not found in any candidate complementary sex determination loci.

Pieris oleracea, formerly Pieries napi, was once a widespread pierid butterfly in New England until the introduction of a biological control agent, Cotesia glomerata. It has been suggested that C. glomerata is responsible for the range reduction of P. oleracea. There are been several introductions of a second more specialized biological control agent, Cotesia rubecula, to the United States since the 1960’s. My first goal was to determine the current distribution and status of P. rapae parasitoids and the effectiveness of C. rubecula as a biological control agent since its release. The findings of a survey I conducted of the parasitoid community of P. rapae indicate that C. rubecula now occurs as far west as North Dakota and has become the dominant parasitoid of P. rapae in the northeastern and north central United States and adjacent parts of southeastern Canada, where it has displaced C. glomerata, the previously dominant parasitoid. Survival of artificially established cohorts of P. rapae larvae was assessed in a collard patch on an organic vegetable farm in western Massachusetts. There was a significant drop in larval survival between the 4th and 5th instar due to parasitism by C. rubecula. This was change from survival curves of P. rapae from a 1985-1986 study, in which there was a significant drop in survival between the 5th instar and pupal stage due to C. glomerata. The final goal of my thesis work is to try to understand why P. oleracea was able to survive at the focal study site in Lenox, MA despite parasitoid pressure and range reduction elsewhere in New England. In olfactometer tests, there was no difference in attractiveness of naïve C. glomerata females to volatiles of either Cardamine pratensis (cuckooflower) foliage, the host plant of P. oleracea or Brassica olercea (collard) foliage (P = 0.51). In order to determine if overtopping by other vegetation may provide an enemy free space for P. oleracea by affecting detection by C. glomerata, cage experiments were conducted. Overtopping vegetation had a significant effect on parasitism by C. glomerata (F = 12.8, df = 3, PP. oleracea has been able to thrive at the Lenox, MA site.

No description available.

Dans un monde changeant et incertain, pouvoir moduler sa réponse phénotypique selon les conditions locales représente un avantage adaptatif majeur. Cette aptitude passe par la récolte d’informations, et plus précisément, dans le cadre de la plasticité du comportement, par la combinaison d’informations passées et présentes. Ceci est rendu possible par l’apprentissage et la mémoire, qui permettent aux animaux de stocker l’information en vue d’une utilisation ultérieure. Cette thèse a pour vocation de renforcer les liens entre écologie comportementale et cognition. Tout d’abord, nous nous sommes penchés sur deux questions propres à l’utilisation d’information passée. (i) Quelle importance est accordée aux informations anciennes face aux récentes ? (ii) En cas de redondance, toutes les informations récoltées sont-elles conservées ? Nous avons montré que (i) l’hyménoptère parasitoïde Venturia canescens accorde un poids égal à l’information issue de l’exploitation de parcelles successives d’hôtes. (ii) Parmi trois sources possibles d’information passée, une seule est utilisée. Dans un second temps, nous avons testé l’hypothèse selon laquelle apprentissage et mémoire ont évolué en réponse au milieu de vie. Nous avons mené une étude comparative sur des V. canescens arrhénotoques et thélytoques vivant dans des habitats contrastés. Les résultats obtenus lors d’un conditionnement olfactif concordent en partie avec nos prédictions, renforçant l’idée d’un lien entre distribution de la ressource et apprentissage. Du point de vue théorique, la question de la valeur adaptative de la durée des différentes phases de mémoire n’a jusqu’ici pas été traitée. Un modèle de simulation est proposé pour commencer à combler cette lacune / In an uncertain and changing world, being able to shape its phenotype according to the current environmental conditions should provide individuals with a major fitness benefit. This depends on information gathering. In the context of behavioural plasticity, it more specifically implies to combine past and current information pieces. Past information use happens through learning and memory, that enables animals to store information in memory for a subsequent decision making. This thesis aims at strengthen the links between behavioural ecology and cognition. First, we tackled two questions specific to past information use. (i) Which weight is given to an older information piece in front of a more recent one? (ii) If several redundant information pieces are gathered, are they all stored? We showed that (i) the parasitoid wasp Venturia canescens seems, at the time scaled we worked with, to weight equally information pieces coming from older and more recent host patches successively foraged. (ii) Among three possible past information sources, only one is stored for a later use. Second, we tested the hypothesis that learning and memory evolved in response to ecological constraints. We conducted a comparative study with arrhenotokous and thelytokous V. canescens thriving in different habitats. Results obtained through olfactory conditioning partially matched our initial predictions; this support the idea of a link between resource distribution and learning features. From the theoretical point of view, the question of the adaptive significance of the length of memory phases has not been tackled yet. Here is shown a model, as a first attempt to fill this gap

Bumblebees are important pollinators, commercially used in large-scale plant growing in greenhouses. Their males produce marking pheromones for mating, which attract young bumblebee queens. These pheromones are often a complicated mixture of chemicals, which is produced in the male labial gland, and the mixture itself is specific for each bumblebee species. The regulation of bumblebee sexual pheromone biosynthesis is largely unknown, and this Master's thesis is focused on the analysis of the mechanisms which lead to the regulation of the Bombus terrestris male pheromone's fat-acid and terpenes biosynthesis, specifically on stereospecific enzymatic reduction of double bond of farnesol. This thesis studies the influence of potential neurohormones on a specific enzymatic mixture, which is involved in the pheromone biosynthesis. Methods used in this project include biochemical, analytic and molecular-biology methods.

Entre os inimigos naturais das moscas-das-frutas, os representantes da subfamília Opiinae (Hymenoptera: Braconidae) têm sido os mais utilizados em programas de controle biológico. Entretanto, algumas espécies da subfamília Alysiinae são comumente relacionadas ao parasitismo desses dípteros, em particular Asobara anastrephae (Muesebeck). No estudo da eficiência desses parasitóides é de fundamental importância o conhecimento dos estímulos utilizados para a localização do hábitat de seus hospedeiros. Dessa forma, foram avaliadas as respostas olfativas do parasitóide exótico Diachasmimorpha longicaudata Ashmead, e dos nativos, Doryctobracon areolatus (Szépligeti) e A. anastrephae a frutos de goiaba (Psidium guajava L.) com e sem larvas de moscasdas- frutas, em condições de laboratório. D. longicaudata e D. areolatus foram também estudados em telado. As fêmeas de D. longicaudata e de D. areolatus responderam aos odores de frutos podres não-infestados, embora D. areolatus também tenha sido atraído aos frutos em maturação inicial (de vez). As fêmeas dessas espécies demonstraram reconhecer os voláteis de frutos com larvas de Ceratitis capitata (Wied.). No entanto, em bioensaios realizados com frutos contendo larvas de diferentes instares, as fêmeas de D. longicaudata não foram capazes de separar frutos com larvas dos primeiros instares dos de terceiro instar de C. capitata. Nas avaliações dos voláteis liberados dos frutos com larvas de C. capitata e de Anastrepha fraterculus (Wied.), as fêmeas de D. longicaudata orientaram-se aos voláteis dos frutos com ambas as espécies de hospedeiros, mas diferiram significativamente dos voláteis com larvas de C. capitata. As fêmeas de D. areolatus também demonstraram respostas para ambas as espécies, mas diferiram significativamente dos voláteis de frutos com larvas de A. fraterculus. As fêmeas de A. anastrephae orientaram-se de forma similar para os campos com odores de frutos infestados com ambas as espécies de moscas-dasfrutas. Em área coberta (telado), as fêmeas de D. longicaudata orientaram-se pelos voláteis de frutos podres com e sem larvas, porém não diferenciaram significativamente os hospedeiros. As fêmeas de D. areolatus não foram atraídas para os frutos nas gaiolas no solo independentemente do hospedeiro, sugerindo que este parasitóide não forrageia em frutos caídos. / Parasitoids of the Opiinae subfamily (Hymenoptera: Braconidae) are among the most used natural enemies in fruit fly control programs. Furthermore, some species of the subfamily Alysiinae, such as Asobara anastrephae (Muesebeck), are commonly associated to the parasitism of these dipterans. The study of efficiency of parasitoids is essential in order to understand the mechanisms that regulate both prey and habitat searching behavior of natural enemies. In this work we evaluated the behavioral response of the native parasitoid species Doryctobracon areolatus (Szépligeti), A. anastrephae as well as the exotic species Diachasmimorpha longicaudata Ashmead, to guava fruit (Psidium guajava L.) with and without fruit flies larvae under laboratory conditions. In addition, behavioral response of D. longicaudata and D. areolatus were also determined under natural conditions. Parasitoid females of D. longicaudata and D. areolatus responded to volatiles from non-infested fermented fruits, moreover D. areolatus also attracted to fruits on initial maturation. Both species recognized volatiles from fruits infested with Ceratitis capitata (Wied.) larvae; however D. longicaudata females were unable to differentiate volatiles from fruit infested with different larval instars of C. capitata. Olfactometer choice bioassays showed that females of both parasitoid species oriented to volatiles released from fruits infested with C. capitata and Anastrepha fraterculus (Wied.) larvae, however preference differed significantly for volatiles associated with each fruit fly species. Under natural conditions, D. longicaudata was attracted to volatiles released from infested and non-infested fermented fruits. Nevertheless, D. areolatus did not respond to volatiles from infested fruits placed on the ground, suggesting that this species do not prey on fallen fruits.

O objetivo do presente trabalho foi selecionar a linhagem mais adequada de T. pretiosum para o controle de T. absoluta na cultura do tomate, dentre as linhagens da coleção do Laboratório de Biologia de Insetos do Departamento de Entomologia e Acarologia da Escola Superior de Agricultura \"Luiz de Queiroz\", e comparar a qualidade dos insetos criados em ovos do hospedeiro alternativo, Anagasta kuehniella (Zeller, 1879) com aquela dos insetos oriundos de ovos de T. absoluta, com vistas à utilização do parasitoide para o controle da traça-do-tomateiro. Para atingir tal objetivo foram realizadas as seguintes etapas: seleção de linhagens, efeito da idade do hospedeiro no parasitismo, efeito do hospedeiro na qualidade do parasitoide e número de parasitoides a ser liberado por ovo da praga. A linhagem PR de T. pretiosum, proveniente do Paraná, foi, entre as estudadas, a mais adequada para o uso em programas de controle biológico de T. absoluta. T. pretiosum parasitou igualmente ovos de T. absoluta de 0 a 48 horas de idade. A capacidade de parasitismo, longevidade, capacidade locomotora e o tamanho do parasitoide foram reduzidos quando provenientes de ovos da traça-do-tomateiro em comparação a insetos emergidos de ovos de A. kuehniella. O número ideal de T. pretiosum a ser liberado na cultura do tomate para o controle de T. absoluta foi superior a 50 parasitoides/ovo. Portanto, T. pretiosum pode ser utilizado em programas de Controle Biológico Aplicado, visto que, devido à menor qualidade dos parasitoides provenientes de ovos de T. absoluta, o inimigo natural terá dificuldades em se estabelecer no campo, indicando ser necessário um grande número de liberações, pois T. pretiosum terá uma ação contra T. absoluta semelhante a um inseticida, desde que os parasitoides que nascerem nas gerações subsequentes às liberações serão menos agressivos e competitivos do que os insetos da natureza. / The aim of this study was to select the most suitable T. pretiosum strain for the biological control of T. absoluta in tomato crops, within the existing strains in the Laboratório de Biologia de Insetos\' colection at Escola Superior de Agricultura \"Luiz de Queiroz\", and compare the quality of the insects reared on eggs of the alternative host Anagasta kuehniella (Zeller, 1879) and on eggs of T. absoluta. For this, the following characteristics were studied: strain selection, host age effect on parasitism, different host effect on parasitoid quality and ideal number of released parasitoid per pest egg. The T. pretiosum strain PR, originated in Paraná state, was the most suitable for its use in T. absoluta biological control programs. T. pretiosum parasitism rate was the same for eggs aged from 0 to 48 hours. T. pretiosum\'s parasitism capability, longevity, mobility capability and parasitoid size were reduced when reared on T. absoluta eggs in comparison to the ones reared on A. kuehniella eggs. The ideal parasitoid number for release in order to control T. absoluta in tomato crops is over 50 per egg. Since the quality of parasitoids hatched from T. absoluta eggs is lower, populations of T. pretiosum will present difficulties to establish itself in the field. Therefore, T. pretiosum should be used in applied biological control programs, where a large number of parasitoids is released in the field from time to time, which will act similarly to insecticides.

Genes de plantas que codificam inibidores de enzimas digestivas de insetos têm sido introduzidos em plantas cultivadas visando o controle de pragas. Os inibidores de proteinases estão presentes nos tecidos vegetais, principalmente nas sementes, e atuam em resposta a ataques por herbívoros e patógenos. Inibidores de serino-proteinases (IPs) dos tipos Bowman-Birk e Kunitz isolados de sementes de soja foram inseridos em variedades de cana-de-açúcar para aumentar a resistência à broca Diatraea saccharalis (Fabr.), principal praga desta cultura. Para utilização de plantas geneticamente modificadas contendo inibidores de proteinases é necessário um conhecimento profundo de sua sustentabilidade e segurança ambiental, determinando a estabilidade da característica inserida e os seus efeitos nos organismos não-alvo. O objetivo desta pesquisa foi avaliar os efeitos diretos e indiretos de inibidores de proteinases de soja em organismos não-alvos: um parasitóide larval, Cotesia flavipes (Cam.) (Hymenoptera: Braconidae); um patógeno, Metarhizium anisopliae (Mestch.) Sorokin (Deuteromycotina: Hyphomycetes); um polinizador, Apis mellifera L. (Hymenoptera: Apidae) e um decompositor, Scheloribates praeincisus (Berlese) (Acari: Oribatida: Scheloribatidae); associados à cultura da cana-de-açúcar. O consumo de Kunitz e BBI não afetou a sobrevivência de S. praeincisus. Por outro lado, a ingestão dos inibidores semi-purificados e purificados do tipo Kunitz diminuiu a duração das fases imaturas de S. praeincisus. A ingestão de folhas de cana GM expressando inibidores de proteinases (Kunitz e BBI) não afetou o tempo de desenvolvimento e a sobrevivência dos imaturos deste oribatídeo quando comparada à ingestão de suas isolinhas. Os inibidores de proteinases semi-purificados e purificados não afetaram a duração dos períodos larval e pupal, o peso e número de pupas e percentual de emergência do parasitóide C. flavipes em D. saccharalis. Por outro lado, a proporção de fêmeas em relação a machos de C. flavipes foi maior no tratamento onde as lagartas foram alimentadas com dieta contendo 0,5% de inibidores semi-purificados comparado-se à testemunha. A proporção fêmea:macho foi significativamente maior também quando os parasitóides foram alimentados com o inibidor do tipo Kunitz em relação ao controle e aos parasitóides alimentados com BBI. A adição de 0,5% (p/v) de inibidores de proteinases semi-purificados e 0,05% (p/v) de inibidores purificados do tipo Kunitz nos meios de cultura MC e BDA resultaram em maiores crescimento vegetativo e produção de conídios de M. anisopliae. Os inibidores purificados do tipo BBI não alteraram a esporulação do fungo. Os resultados dos estudos com A. mellifera não foram conclusivos e novas investigações precisam ser conduzidas para esclarecer os potenciais efeitos de inibidores de proteinases em abelhas. De uma forma geral, observou-se que os inibidores de proteinases (Kunitz e BBI) não afetaram negativamente os organismos não-alvo testados. Por outro lado, a ingestão de inibidor do tipo Kunitz alterou positivamente alguns parâmetros biológicos de C. flavipes, M. anisopliae e S. praeincisus. / Genes of plants expressing insect proteinase inhibitors have been introduced into plants for pest control. Proteases inhibitors are present in plant tissues, mainly in seeds, and act in response to predators and pathogens. The Bowman-Birk type and Kunitz type of serine proteases inhibitors (PI) from soybean seeds are been used to increase resistance of sugarcane to Diatraea saccharalis (Fabr.), the most important pest of this crop. The sustainability and environmental safety of PI crops is still unknown. For these reasons, it is necessary to understand the stability and the non-target effects of this new trait. The objective of this study was to evaluate the direct and indirect effects of soybean PI on the following non-target organisms associated to sugarcane: the larval parasitoid, Cotesia flavipes (Cam.) (Hymenoptera: Braconidae); the entomopathogen, Metarhizium anisopliae (Mestch.) Sorokin (Deuteromycotina: Hyphomycetes); the pollinator Apis mellifera L. (Hymenoptera: Apidae) and the soil mite involved in the process of recycling organic matter, Scheloribates praeincisus (Berlese) (Acari: Oribatida: Scheloribatidae). Kunitz and BBI did not affect S. praeincisus survival. On the other hand, Kunitz semi-purified and purified inhibitor ingestion reduced duration of the immature stages of S. praeincisus. Ingestion of GM senescent leaves did not have an effect on mite immatures development time and survival compared to ingestion of its isolines leaves. The semi-purified and purified proteinases inhibitors did not alter either the duration of larval and pupal stages of C. flavipes on D. saccharalis, or weight and number of pupae and parasitoid emergence. In other hand, the parasitism and proportion of female was higher on the treatment where caterpillars were fed with diet containing 0.5% of semi-purified inhibitors, comparing to control. The ratio female:male was significantly higher also when parasitoids were fed to the Kunitz type inhibitor compared to the control and BBI. The addition of 0.5 % (w/v) of semi- purified proteinase inhibitors and 0.05% (w/v) of Kunitz type purified inhibitors on two culture media (CM and PDA), resulted in increase of vegetative growth and production of conidia. BBI type purified inhibitors did not change the fungus sporulation. The results from the studies with A. mellifera were not conclusive and investigations are needed to clarify the potential impact of proteinase inhibitors on A. mellifera. Overall, proteinase inhibitors (Kunitz and BBI) did not negatively affect the non-target organisms tested. Conversely, ingestion of the Kunitz type of proteinase inhibitors altered positively some biological parameters of C. flavipes, M. anisopliae and S. praeincisus.

The objective of this study was to characterize the wild bee fauna of a managed mixed-grass prairie in southwestern Manitoba. Weekly sampling using two methods, sweep-netting and bee bowls, was conducted over two years (2005-2006) at three sites within the Yellow Quill Mixed-grass Prairie Preserve. Spatial and seasonal patterns in diversity indices, taxonomic composition and ecological composition of the bee fauna were identified and investigated in relation to sampling method, environmental conditions, and floral resource availability. A total of 7014 individual bees representing five families and 100 species were collected. Numerically, social nesters from the genera Lasioglossum and Bombus dominated, while mining species of Andrena represented the greatest species richness. Observed spatial and seasonal patterns in the abundance, diversity and composition of the bee community were strongly modified by sampling method, resource limitation in the second year and the presence of the exotic invasive plant leafy spurge (Euphorbia esula). / October 2007