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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Evaluating sex pheromone monitoring as a tool in the integrated management of vine mealybug, Planococcus ficus (signoret) (Homoptera: Pseudococcidae) / M.J. Kotze

Kotze, Maria Johanna January 2006 (has links)
The vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudococcidae) is a pest with significant economic impact on the grape growing industry in South Africa and other parts of the world. With the isolation and synthesizing of the vine mealybug sex pheromone in 2001, new control options for the integrated management of the vine mealybug have been created. The status of sex pheromone monitoring as a tool in the integrated management of the vine mealybug has been evaluated from different perspectives. A significant quantitative difference in male vine mealybug trap catch numbers has been observed between wine and table grape vineyards and results indicated that there were differences in the susceptibility of grape cultivars to vine mealybug. Currently, the delta trap design is the accepted trap design for vine mealybug monitoring. No studies have yet been conducted to determine the optimum trap parameters like size or design. Population pressure may have an influence on the qualitative efficiency of various trap designs. The basis for degree-day forecasting models has been established adequately. However, refinements need to be done and the incorporation of factors such as humidity and regionality also need to be considered. Daily maximum temperatures fluctuating around the upper developmental threshold temperature for prolonged periods of time seemed to suppress population numbers. Different vineyard management practices exist for wine and table grape production. While an action threshold of 65 vine mealybug males per trap per two-week period seems an acceptable threshold for table grape production, it may not be appropriate for wine grape (or raisin grape) production. Using sex pheromone traps for population monitoring is a valid technique in the arsenal of management tactics against the vine mealybug. However, refinements and validation of research results must be done further to build credibility into the monitoring system. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
72

The costs and benefits of resistance and tolerance behaviors against Varroa mite (Varroa destructor Anderson and Trueman) in honey bee (Apis mellifera L.)

Bahreini, Rassol 16 December 2014 (has links)
Managed honey bee colonies face severe winter losses in northern climates. In my studies, interactions between genotypes of bees (genetically selected stock and unselected stock) with different levels of resistance and tolerance to varroa mites were assessed under a variety of treatment combinations to quantify effects of queen pheromone, acaricide treatment, wintering method, ventilation condition and pathogen infection on the costs and benefits associated with mite removal and mite-tolerance behaviors. In most of the experiments, mite-resistance caused greater varroa mite mortality within selected stock relative to unselected stock. Artificial and natural sources of queen pheromone caused greater varroa mite mortality within honey bee colonies relative to queenless colonies. While mite resistance had significant benefits, I showed that when producers selected colonies containing some mite resistance traits, it was traits associated with mite-tolerance and not mite-resistance were maintained and contributed to wintering success. Tolerance was effective at two levels of mites as obtained by late autumn treatment of colonies with oxalic but treatment did not improve wintering performance of either stock. Selected stock showed greater colony size, survival and resulted in more viable colonies in spring in comparison to unselected stock with similar initial mite levels (0.16 mites per bee). Selected stock showed greater relative wintering success than unselected stock when wintered indoors than when wintered outdoors but indoor wintering improved colony survival in both stocks relative to outdoor wintering. Carbon dioxide level increased within the winter bee cluster when colonies were maintained under restricted-ventilation (mean 3.82±0.031%, range 0.43-8.44%) and restricted ventilation increased mite mortality by 138% relative to standard-ventilation (mean 1.29±0.031%, range 0.09-5.26%), but restricted-ventilation did not affect bee mortality in comparison to standard-ventilation. In a laboratory study, I showed that Nosema inoculation (with co-infections of N. ceranae and N. apis) suppressed the effectiveness of mite removal behavior within selected bees relative to unselected bees. N. ceranae was more abundant than N. apis. Bees with greater mite removal capacities had higher costs associated with varroa-resistance as indicated by greater bee mortality rates when inoculated with varroa but bee mortality was not affected in Nosema inoculated bees.
73

Alternative rownstream roles for Ste2p and an α-arrestin in sacccharomyces cerevisiae mating

2014 November 1900 (has links)
Ste2p and Ste3p are well-characterized yeast pheromone G-protein Coupled Receptors (GPCR) those are involved in the signaling of mating responses that lead to cell fusion. Their signaling–associated interactions with G-protein/MAPK signal transduction machinery are well established, homologous to those in mammalian systems, and serve as a simplified model system in GPCR research. While the arrestin- mediated biased signaling mechanism of mammalian GPCR has not been discovered for the pheromone receptors, a recent demonstration of α-arrestins being involved in the internalization of the pheromone GPCR, Ste2p was reported. The present study was designed to reevaluate and extend the alternate functionality for pheromone receptors and to determine the role of yeast arrestins in the yeast mating. Specific residues in the TM6 of Ste2p exhibiting strong mating and constitutive MAPK signaling were combined and investigated in terms of their effect on MAPK signal transduction leading to cell cycle arrest as well as their impact on downstream mating projection formation and zygote formation events. Our findings indicate that Ste2p possess as specific residues that govern its relative bias for mediating MAPK signaling or mating events. Relative dose response experiments accounting for systemic and observation bias for these mutations yielded evidence of mutational-derived functional biases for Ste2p and further validated the alternate pheromone dependent functionalities for Ste2p. Further, arrestin knockout and knock-in studies showed that Art1 (Ldb19) is selectively involved in the regulation of zygote formation but not MAPK signal transduction following the binding of ligand to Ste2p receptors. In addition, ligand stimulated selective localization of Art1 (Ldb19) to the mating projection, implicating it in the regulation of downstream mating functionalities. Overall, while leaving the full mechanism of alternate/biased Ste2p signaling to be elucidated, these results highlight the possibility of continued relevance of the yeast pheromone-mating pathway as a simplified model for GPCR research in the context of arrestin-mediated biased GPCR signaling.
74

Development of a Semiochemical-based Monitoring System for Diamondback Moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), in Canola in Alberta

Miluch, Christine 11 1900 (has links)
Studies focused on developing a semiochemical-based monitoring system for Plutella xylostella (L.) using sex pheromone and Z3-hexenyl acetate. A commercially available pheromone trapping system was used to capture male moths at sites in Alberta in 2007 and 2008. Larval sampling occurred every two weeks after the first males were captured. Male moth capture was predictive of larval density on individual sample dates during the growing season. The predictive capability of pheromone-baited trap capture was not in direct proportion to population density and was inconsistent. Modifications to the trapping system were tested to improve attractiveness. Adding Z3-hexenyl acetate at various doses to pheromone did not improve the attractiveness to males over pheromone alone and did not attract significant numbers of females when tested at various times during the flight season. Trap height and colour did not influence male capture. Pheromone dose and lure type did influence male moth capture in traps. / Plant Science
75

Neoleucinodes elegantalis (Guenée) (Lep.: Crambidae) em tomateiro estaqueado : dinâmica populacional, nível de controle com feromônio sexual e eficiência de agrotóxicos /

Benvenga, Sérgio Roberto. January 2009 (has links)
Orientador: Sergio Antonio De Bortoli / Banca: José Eudes de Morais Oliveira / Banca: José Ednilson Miranda / Banca: Robson Thomaz Thuler / Banca: Marcelo da Costa Ferreira / Resumo: A relação entre a infestação da broca-pequena-do-fruto, Neoleucinodes elegantalis, e a produtividade foi avaliada na cultura do tomate, Lycopersicon esculentum, em ciclo de verão e inverno, com o objetivo de analisar a influência da infestação na produtividade da cultura e aperfeiçoar a tomada de decisão de controle. Armadilhas com feromônio sexual foram instaladas em parcelas experimentais e na mesma data foi avaliada a densidade de adultos capturados e a infestação de plantas com ovos nos frutos. A pressão populacional foi mais expressiva nos cultivos de verão. O aumento no número de adultos capturados nas armadilhas correspondeu a um incremento na infestação de ovos nos frutos e houve influência positiva da infestação de plantas com a produção descartada. Definiu-se que a tomada de decisão de controle deve ocorrer quando for capturada a média de 0,24 e de 0,23 adultos na armadilha por dia, nos cultivos de verão e de inverno, respectivamente. Numa etapa complementar avaliou-se a eficiência de inseticidas sobre os ovos (ação ovicida), lagartas recém-eclodidas (ação de choque) e em fase de crescimento (ação fisiológica), sob condições de laboratório. Para tanto, frutos com ovos foram imersos na calda inseticida para avaliação da ação ovicida e ação de choque aos 7 dias após a imersão e aos 21 dias, para a ação fisiológica. Foram avaliados 24 inseticidas e uma testemunha em aplicação isolada e com a adição de óleo vegetal (0,25%), respectivamente. Trebon 100 SC (etofenprox; 200 mL de produto comercial/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) e Vertimec 18 CE (abamectin; 100 mL) apresentaram ação efetiva sobre os ovos e lagartas de N. elegantalis. A adição do adjuvante interfiriu de forma significativa e positiva na eficiência dos inseticidas. / Abstract: The relationship between the infestation of Neoleucinodes elegantalis and productivity was evaluated in tomato crops, Lycopersicon esculentum, in summer and winter cycles, with the objective of analyzing the infestation influence on the productivity and improving the decision making control. Sex pheromone traps were installed in experimental plots and at the same date was assessed the density of adults caught and infestation of plants with eggs in fruits. The population pressure was more significant in the summer crops. The increase in the number of adults caught in traps corresponded to an increase in infestation of eggs in the fruit and with positive influence of the infestation on plants with the production. Decision-making control should occur when the average catch of 0.24 and 0.23 adults in the trap per day in the summer and winter crops, respectively. An additional step was conducted to evaluate the efficiency of insecticides on the eggs (ovicidal action), newly-hatched larvae (shock action) and in the growth phase (physiological action) under laboratory conditions. Fruit with eggs were emmerged in the insecticide solutions for assessing ovicidal action and the shock action at 7 days after immersion and at 21 days, to physiological action. It was evaluated 24 insecticides and a control application in with and without addition of vegetable oil (0.25%). Trebon 100 SC (etofenprox; 200 mL of commercial product/100 L), Lannate BR (methomil; 100 mL), Thiobel 500 (cartap; 250 g) and Vertimec 18 EC (abamectin; 100 mL) had action on the eggs and larvae of N. elegantalis. The addition of adjuvant showed significantly and positively effects in the insecticides efficiency. / Doutor
76

FUNCTIONAL RESPONSE OF TEMNOCHILA VIRESCENS, EFFECT OF COMPETITION WITH THANASIMUS DUBIUS ON ADULT IPS GRANDICOLLIS SURVIVAL, AND DETERMINATION OF PHEROMONE PREFERENCE TYPES

Chism, Scott B. 01 August 2013 (has links)
Arthropod predators are able to influence the population dynamics of forest insects such as bark beetles. Two common predators of bark beetles are Temnochila virescens (F.) (Coleoptera: Trogositidae) and Thanasimus dubius (F.) (Coleoptera: Cleridae). Studies on T. virescens ecology have been few and not quantitative. Also, in recent years there has been increased focus on multiple-predator effects on the population dynamics of a single prey species, which better describes a natural system. Therefore, a series of three studies was conducted to provide a general overview of T. virescens ecology and its potential use for biological control. The first study examined the functional response of T. virescens toward its Ips prey. The second evaluated the impacts of intraguild competition between T. virescens and T. dubius adults on predation of a mutual prey species, I. grandicollis. The third determined if there were differences in pheromone preference among individual T. virescens adults. To evaluate the functional response, T. virescens and Ips grandicollis (Eichhoff) adults were combined in varying densities. Ips grandicollis survival was assessed by examining the number of prey eaten in relation to predator and prey densities. I found that a type II functional response model incorporating interference provided a good fit for the data. The interference was strong enough that a ratio-dependent model fit the data just as well as the full model. The effect of competition between T. dubius and T. virescens adults on I. grandicollis survival was determined by placing varying numbers of each predator with a set prey number. I found a significant interaction between densities of the two predators, which indicates possible emergent predator effects. The combined effect of the predators was risk reducing for prey, likely because of intraguild predation. The predator T. dubius alone was more efficient at reducing the number of prey adults successfully entering the log. This study indicates the importance of low density releases of these predators for augmentative biological control, to reduce the effects of intraspecific competition. To determine if there were differences in pheromone preference among individual T. virescens adults, a mark-release-recapture experiment was combined in the field to provide a choice test between ipsenol and ipsdienol pheromones. Temnochila virescens adults that were initially captured on ipsenol were more frequently recaptured with this pheromone, while those first captured on ipsdienol were recaptured on both pheromones. This suggests populations of T. virescens are composed of specialists attracted only to ipsenol and generalists attracted to both ipsdienol and ipsenol pheromones.
77

Estudo da variabilidade da frequência cardíaca em equinos durante o casqueamento com a utilização de feromônio materno equino / Study of the heart rate variability in equines during hoof conformation procedure with the use of maternal equine pheromone.

Paula, Renata Alves de 06 June 2018 (has links)
Submitted by Renata Alves De Paula (medvetrenata@hotmail.com) on 2018-07-12T10:32:49Z No. of bitstreams: 1 Texto completo .pdf: 1611384 bytes, checksum: f6e1b93fde62170229cda125f7fbea46 (MD5) / Approved for entry into archive by Luciana Pizzani null (luciana@btu.unesp.br) on 2018-07-13T18:50:06Z (GMT) No. of bitstreams: 1 paula_ra_me_bot.pdf: 1611384 bytes, checksum: f6e1b93fde62170229cda125f7fbea46 (MD5) / Made available in DSpace on 2018-07-13T18:50:06Z (GMT). No. of bitstreams: 1 paula_ra_me_bot.pdf: 1611384 bytes, checksum: f6e1b93fde62170229cda125f7fbea46 (MD5) Previous issue date: 2018-06-06 / A equinocultura encontra-se em constante crescimento e por isso há um maior interesse em estudos científicos que favoreçam a relação homem animal garantindo consequentemente o bem-estar animal. Discussões são cada vez mais frequentes, envolvendo não só as formas de criação como também as práticas as quais são submetidos. A feromonioterapia é uma nova alternativa que vem sendo estudada a fim de tranquilizar e reduzir os problemas relacionados ao medo, ansiedade e fobia e limitando as manifestações do sistema nervoso autônomo e consequentemente o estresse a esses animais. Para tanto, o objetivo deste estudo foi avaliar a variabilidade da frequência cardíaca (VFC) de equinos submetidos ao tratamento com Feromônio Materno Equino (FME) durante o procedimento de casqueamento. Foram avaliados 20 potros, com idade média de vinte e quatro meses, machos e fêmeas sem experiência prévia ao casqueamento que foram divididos em dois grupos (A e B) onde um deles recebeu tratamento com FME e o outro placebo (excipiente sem o princípio ativo), considerado randomizado e duplo-cego. Os parâmetros avaliados foram frequência cardíaca (FC), frequência respiratória (FR), glicemia, VFC e análise de reações comportamentais. O exame clínico foi avaliado em dois momentos sendo: M1 (20 minutos previamente ao casqueamento) e M2 (20 minutos após o casqueamento). Já a VFC, foi avaliada nos momentos pré, trans e pós casqueamento. Os resultados demonstraram que não houve diferenças estatísticas dos parâmetros clínicos avaliados (FC, FR e glicemia) em comparação com os grupos (FME e placebo) em relação aos momentos M1 e M2. A FC mínima, FC média e FC máxima e principalmente os índices da VFC (SDNN, SDANN e SDNNi, RMSSD e PNN50) também não diferiram quando se comparou os grupos nos momentos pré, trans e pós casqueamento. Embora não tenha ocorrido significância, observou-se tendência a diminuição dos parâmetros FC, glicemia e reatividade em um dos grupos, havendo percepção nítida de mudança no comportamento durante o casqueamento sugerindo maior tranquilidade dos equinos durante o procedimento, com a feromonioterapia. / The horse breeding is found in constant growth and then there is a greater interest in scientific studies that favor the animal man relationship therefore ensuring animal welfare. Discussions are increasingly frequent, involving not only the forms of creation but also the practices which are submitted. Pheromone therapy is a new alternative that has been studied in order to reassure and reduce the problems related to fear, anxiety and phobia and limiting the manifestations of the autonomic nervous system and consequently the stress to these animals. For this purpose, the aim of this study was to evaluate the heart rate variability (HRV) of horses submitted to treatment with Maternal Equine Pheromone (MEP) during the hoof trimming. We evaluated 20 foals, with an average age of twenty-four months, males and females without prior experience to the hoof trimming that were divided into two groups (A and B) where one received treatment wich MEP and and the other placebo (excipient without the active ingredient), considered randomized and double-blind. The parameters evaluated were heart rate (HR), respiratory rate (FR), blood glucose, HRV and analysis of behavioral reactions. The clinical examination was studied in two moments: M1 (20 minutes before the procedure hoof trimming) and M2 (20 minutes after the procedure hoof trimming). Already the HRV was evaluated in pre, trans and post procedure hoof trimming. The results showed that there was no statistical differences of clinical parameters evaluated (FC, FR and glucose) compared to the groups (MEP and placebo) in relation to the moments M1 and M2. Minimum FC, medium FC and maximum FC and especially the index of VFC (SDNN, SDANN e SDNNi, RMSSD e PNN50) also did not differ when compared the groups in moments pre, during and after procedure hoof trimming. Although there has not been significance there was a tendency to decrease the parameters FC, blood glucose and reactivity in one of the groups, there being clear perception of change in behavior during procedure hoof trimming with pheromone therapy suggesting greater tranquility of equines during the procedure.
78

Estudo da variabilidade da frequência cardíaca em equinos durante o casqueamento com a utilização de feromônio materno equino

Paula, Renata Alves de January 2018 (has links)
Orientador: Simone Biagio Chiacchio / Resumo: A equinocultura encontra-se em constante crescimento e por isso há um maior interesse em estudos científicos que favoreçam a relação homem animal garantindo consequentemente o bem-estar animal. Discussões são cada vez mais frequentes, envolvendo não só as formas de criação como também as práticas as quais são submetidos. A feromonioterapia é uma nova alternativa que vem sendo estudada a fim de tranquilizar e reduzir os problemas relacionados ao medo, ansiedade e fobia e limitando as manifestações do sistema nervoso autônomo e consequentemente o estresse a esses animais. Para tanto, o objetivo deste estudo foi avaliar a variabilidade da frequência cardíaca (VFC) de equinos submetidos ao tratamento com Feromônio Materno Equino (FME) durante o procedimento de casqueamento. Foram avaliados 20 potros, com idade média de vinte e quatro meses, machos e fêmeas sem experiência prévia ao casqueamento que foram divididos em dois grupos (A e B) onde um deles recebeu tratamento com FME e o outro placebo (excipiente sem o princípio ativo), considerado randomizado e duplo-cego. Os parâmetros avaliados foram frequência cardíaca (FC), frequência respiratória (FR), glicemia, VFC e análise de reações comportamentais. O exame clínico foi avaliado em dois momentos sendo: M1 (20 minutos previamente ao casqueamento) e M2 (20 minutos após o casqueamento). Já a VFC, foi avaliada nos momentos pré, trans e pós casqueamento. Os resultados demonstraram que não houve diferenças estatísticas dos parâmetros... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The horse breeding is found in constant growth and then there is a greater interest in scientific studies that favor the animal man relationship therefore ensuring animal welfare. Discussions are increasingly frequent, involving not only the forms of creation but also the practices which are submitted. Pheromone therapy is a new alternative that has been studied in order to reassure and reduce the problems related to fear, anxiety and phobia and limiting the manifestations of the autonomic nervous system and consequently the stress to these animals. For this purpose, the aim of this study was to evaluate the heart rate variability (HRV) of horses submitted to treatment with Maternal Equine Pheromone (MEP) during the hoof trimming. We evaluated 20 foals, with an average age of twenty-four months, males and females without prior experience to the hoof trimming that were divided into two groups (A and B) where one received treatment wich MEP and and the other placebo (excipient without the active ingredient), considered randomized and double-blind. The parameters evaluated were heart rate (HR), respiratory rate (FR), blood glucose, HRV and analysis of behavioral reactions. The clinical examination was studied in two moments: M1 (20 minutes before the procedure hoof trimming) and M2 (20 minutes after the procedure hoof trimming). Already the HRV was evaluated in pre, trans and post procedure hoof trimming. The results showed that there was no statistical differences of clinical p... (Complete abstract click electronic access below) / Mestre
79

Anatomia, histologia, histoquímica e ultra-estrutura das glândulas salivares cefálicas de abelhas eussociais (Hymenoptera, apidae): Silvana Beani Poiani. -

Poiani, Silvana Beani [UNESP] 09 August 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-09Bitstream added on 2014-06-13T19:08:37Z : No. of bitstreams: 1 poiani_sb_me_rcla.pdf: 2055835 bytes, checksum: b7f2f558cfec93ce311844965eb141e0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As abelhas eussociais apresentam uma variedade de glândulas exócrinas distribuídas por todo o corpo, cujos produtos são usados no desempenho de suas tarefas. Em todos os insetos, pares de glândulas estão associados às peças bucais e, nas abelhas, as principais destas glândulas estão ligadas ao lábio (glândulas labiais ou salivares), às mandíbulas (glândulas mandibulares) e ao assoalho da cavidade bucal (glândulas hipofaríngeas). O par de glândulas labiais ou salivares dos insetos adultos localiza-se no tórax, porém ramos cefálicos se desenvolvem em algumas espécies de abelhas, formando as glândulas salivares cefálicas, as quais são plenamente desenvolvidas em algumas espécies da subfamília Apinae. O presente trabalho estudou a histologia e a histoquímica das glândulas salivares cefálicas de fêmeas e machos, em diferentes idades, de Apis mellifera e Scaptotrigona postica. Os resultados mostram que a histologia das glândulas salivares cefálicas difere entre as espécies. Enquanto as células alveolares e dos ductos são predominantemente cúbicas nas operárias e rainhas de A. mellifera, em S. postica passam de cúbicas a escamosas conforme a operária envelhece, e os ductos, nesta espécie, são invariavelmente constituídos por células escamosas. Machos recém-emergidos de A. mellifera apresentam a glândula com grau de desenvolvimento semelhante ao das operárias recém-emergidas de sua espécie, porém conforme atingem a maturidade sexual, ocorre regressão glandular de modo que nem sempre foi possível encontrá-la. Por outro lado, machos velhos de S. postica são dotados de glândulas tão desenvolvidas quanto as fêmeas de sua espécie... / Eusocial bees present a variety exocrine glands disperse on body whose products are used in tasks performance. Pairs of glands are attached at mouthparts in whole insects and, in bees, main glands are attached to labium (labial or salivary glands), mandibules (mandibular glands) and floor mouth cavity (hiphofaringeal glands). Adult insects labial or salivary pair glands are located in torax. However cephalic branchs develop in some bees species, composing the cephalic salivary glands which are completely develop in some species of Apinae subfamily. The present work studied the histology and histochemic of females and males cephalic salivary glands of Apis mellifera and Scaptotrigona postica in different ages. The histology results showed cephalic salivary glands differs between species. While cells of alveoli and ducts are primarily cuboidal in workers and queens of A. mellifera, in workers of S. postica, cells undergo of cuboidal to squamous with age and ducts invariably consist of squamous cells. Newly emerged males of A. mellifera exhibit glands in developmental stages similar to that of newly emerged workers of their species. However, as males become sexually mature, the gland degenerates difficulting its localization. Nevertheless, old males of S. postica present glands as developed as those of females of their species. Histochemical techniques demonstrate no protein inclusions and indicated the secretion of glands of workers and queens of both species were neutral lipids. The secretion gradually accumulates in the lumen of alveoli, and as a result, foragers and egg-laying queens exhibit more turgid alveoli that younger individuals... (Complete abstract click electronic access below)
80

Decoding Brood Pheromone: The Releaser and Primer Effects of Young and Old Larvae on Honey Bee (Apis mellifera) Workers

January 2014 (has links)
abstract: How a colony regulates the division of labor to forage for nutritional resources while accommodating for changes in colony demography is a fundamental question in the sociobiology of social insects. In honey bee, Apis mellifera, brood composition impacts the division of labor, but it is unknown if colonies adjust the allocation of foragers to carbohydrate and protein resources based on changes in the age demography of larvae and the pheromones they produce. Young and old larvae produce pheromones that differ in composition and volatility. In turn, nurses differentially provision larvae, feeding developing young worker larvae a surplus diet that is more queen-like in protein composition and food availability, while old larvae receive a diet that mimics the sugar composition of the queen larval diet but is restrictively fed instead of provided ad lib. This research investigated how larval age and the larval pheromone e-β ocimene (eβ) impact foraging activity and foraging load. Additional cage studies were conducted to determine if eβ interacts synergistically with queen mandibular pheromone (QMP) to suppress ovary activation and prime worker physiology for nursing behavior. Lastly, the priming effects of larval age and eβ on worker physiology and the transition from in-hive nursing tasks to outside foraging were examined. Results indicate that workers differentially respond to larvae of different ages, likely by detecting changes in the composition of the pheromones they emit. This resulted in adjustments to the foraging division of labor (pollen vs. nectar) to ensure that the nutritional needs of the colony's brood were met. For younger larvae and eβ, this resulted in a bias favoring pollen collection. The cage studies reveal that both eβ and QMP suppressed ovary activation, but the larval pheromone was more effective. Maturing in an environment of young or old larvae primed bees for nursing and impacted important endocrine titers involved in the transition to foraging, so bees maturing in the presence of larvae foraged earlier than control bees reared with no brood. / Dissertation/Thesis / Ph.D. Biology 2014

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