The development of three colonies of Bombus fervidus (Fabricius) and two of Bombus pennsylvanicus (Degeer) was studied. Population levels and the production of males and young queens varied among colonies and between years. Mean longevity of worker bees decreased significantly toward the end of the season. Mean size of emerging worker bees increased significantly with time. The decreased survivorship may be related to the seasonal size increase of the workers, which would result in an increased proportion of foragers. Age-specific life tables and survivorship curves were developed for workers within colonies, and for workers in cohorts based on emergence date. An increase in brood developmental times occurred near the end of the colony cycle. In the two B. pennsylvanicus colonies, oviposition of fertilized eggs decreased during the transition period from worker to queen production, and large numbers of male-producing eggs were laid. At the time of queen production a sudden increase in size of emerging females occurred. Neither a gradual nor a sudden change in larva/worker ratio appears sufficient to explain caste determination. Rates of parasitization of bumble bee queens at three sites in Southwestern Virginia were studied. Endoparasites of spring queens included Locustacarus buchneri (Stammer) (Acarina: Podapolipidae), a mite infesting the abdominal air sacs; the nematode Sphaerularia bombi Dufour (Tylenchida: Nematoda), and gregarious braconid larvae, probably Syntretus sp. (Hymenoptera: Braconidae). Ectoparasites included hypopi of the mite Kuzinia americana Delfinado and Baker (Acari: Acaridae) and Parasitus spp. mites (Acari: Parasitidae). / M.S.

The loss of managed honey bee colonies, resulting from their unintentional exposure to pesticides, is a topic of concern for the agricultural and apicultural industry. Current methods for reducing pesticide exposure to bees involve the application of pesticides before crop bloom or in the evening when foraging bees are less likely to be exposed to these applications. There is an urgent need for additional protection procedures to reduce the annual losses of managed bee colonies. Another method for protecting these pollinators is the use of chemical deterrents to reduce the interaction times of foraging bees with pesticide-treated crops. Historically, insect repellents (IRs) have been used to prevent the spread of deadly human diseases by arthropod vectors. However, it has been shown that bees can be repelled from pesticide-treated crops using DEET and bee pheromonal compounds. Here, I report the toxicological and deterrent effects of bee pheromonal compounds, as well as the deterrent effects of heterocyclic amines (HCAs) on bees. The results of this study indicate that the bee pheromonal compounds, at 8, 20, 60 and 100% concentrations, are toxic to bees and inhibit the feeding of bees within a confined space. Additionally, the pheromonal compounds and the HCAs are as efficacious as DEET in deterring bees from treated food sources. The HCA piperidine was observed to effectively deter bee foragers from a sugar feeder in a high-tunnel experiment as well as from melon flowers and knapweed in field experiments. Electroantennogram recordings were conducted to verify an olfactory response of the bees to the tested compounds. Pheromonal compounds were readily detected by bee antennae; whereas, the HCAs did not elicit significant responses in the bee antennae. These data suggest that bee pheromonal compounds, as well as HCAs, may serve as candidates for the further investigation as repellents to protect bees from unintentional pesticide exposures. / Ph. D.

The honey bee, Apis mellifera, provides about $15 billion USD in crop value each year in the U.S. alone in the form of pollination services. Since 2006, commercial beekeepers have reported an average annual overwintering loss of about 28.6% of all managed colonies. There are many factors that are thought to contribute to colony loss including bee-specific pests (e.g. the Varroa destructor mite), bee-specific pathogens (e.g. Nosema fungus), modern beekeeping practices, diminished genetic variability, poor queens, climate change, and exposure to agricultural pesticides. While not the single cause of colony loss, the neonicotinoid insecticides elicit sublethal effects to honey bees that could increase their sensitivities to other stressors that affect colony health. Previous studies found that honey bees have differential sensitivities to the neonicotinoid insecticide imidacloprid, which suggest a mechanism of tolerance to the insecticide in certain colonies. In this study, I examined the imidacloprid sensitivity of honey bees collected from different colonies. After determining a range of LC50 values in the tested colonies, I examined the metabolic detoxification activities of honey bees collected from two colonies that represented the highest and lowest LC50 values, between which there was a 36-fold difference in their LC50 values. I discovered that of the three main families of metabolic detoxification enzymes, general esterases, cytochrome P450 monooxygenases, and glutathione S-transferases (GSTs), a reduction of GST activity with diethyl maleate (DEM) significantly increased imidacloprid-mediated mortality to the honey bees. A comparative analysis of GST kinetic activity from imidacloprid-susceptible and -insensitive honey bees revealed a lower bimolecular inhibition rate constant (ki) for imidacloprid-insensitive individuals (5.07 ± 0.098 nmol/min/mg protein) compared to the imidacloprid-sensitive honey bees (17.23 ± 1.235 nmol/min/mg protein). The IC50 of DEM estimated for bees from each colony showed that the imidacloprid-susceptible honey bees possess a higher IC50 (10 μM) than that of the tolerant honey bees (3 μM). These data suggest that the GSTs in the imidacloprid-tolerant honey bees might be a more efficient detoxification mechanism for the conjugation and elimination of imidacloprid, or imidacloprid metabolites, compared to that of imidacloprid-susceptible honey bees. Therefore, I hypothesize that the differences in metabolic detoxification enzyme activities of honey bees collected from different colonies can result in the differential toxicities of honey bees exposed to neonicotinoid insecticides, such as imidacloprid. However, a thorough examination of imidacloprid detoxification in honey bees is warranted to confirm this hypothesis. / Master of Science in Life Sciences

The decline of honey bee (Apis mellifera) colony numbers in recent years presents an economic and ecological threat to agriculture. One outstanding threat to honey bees is the unintended exposure to agricultural pesticides. Previous studies report that acute exposures to the common-use herbicide atrazine elicit oxidative stress in non-target insects; however, little information is currently available on the exposure risk of atrazine to honey bees. This project examined biochemical and molecular oxidative stress response markers of honey bees following laboratory and field treatments of atrazine. Laboratory experiments were conducted with honey bees exposed to increasing concentrations of atrazine for 24 h whereas hive experiments were conducted with bees exposed to one sub-lethal concentration of atrazine for 28 d. The overall antioxidant enzyme activities of atrazine-treated honey bees were decreased compared to the untreated honey bees in both the laboratory and hive experiments. After exposure to atrazine in the laboratory and field, semi-quantitative RT-PCR analysis of antioxidant-encoding genes reveals the differential expression of genes in atrazine-treated bees that are important for oxidative stress tolerance in the laboratory and field experiments. Here, we provide evidence that the laboratory and hive exposure of honey bees to the common-use herbicide atrazine results in oxidative stress responses that can compromise the health of bee colonies. The data will be discussed with regard to the protection of these pollinators against the untended exposure of agricultural pesticides. / Master of Science in Life Sciences

No description available.

BACKGROUND: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. RESULTS: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A.cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. CONCLUSIONS: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory.

Title of the Thesis The Palynological Analysis of the Pollen Collected by Honey Bee (Apis mellifera) in the Prague-West Area Abstract This diploma thesis underlines the importance and significance of bee pasture. The first part of the thesis contains the presentation of the honey bee (Apis mellifera). It also describes the structure of the pollen grain, pollen as such, and its use regarding bee nutrition, the factors determining bee harvest of pollen, the means of its collecting and the use of bee pollen and bee bread. Furthermore, there are characteristics of pollen pasture in the time of early spring, spring, summer, late summer and autumn. The second part is dedicated to the palynological analysis of the area of Prague-West, Úhonice. The diploma thesis contains the evaluation of the food offer for the bees from the aforementioned location, and the summary of pollen-yielding plants blooming between 1 April 2017 and 27 June 2017. The sampling of pollen balls, which had taken place within this time span, provided the initial information about the nutrition of bees as well as the data regarding the diversity of plant species in the chosen location. In total, the samples contained 98 kinds of plants, out of which 31 were dominantly present above the limit of 6 percent. The longest lasting source of pollen was...

The inadvertent spread of exotic pests and pathogens has resulted in devastating losses for bees. The vast majority of bee disease research has focused on a single species of managed bee, the European honey bee (Apis mellifera). More recently, pathogen spillover from managed bees is implicated in the decline of several bumble bee species (Bombus spp.) demonstrating a need to better understand the mechanisms driving disease prevalence in bees, transmission routes, and spillover events. RNA viruses, once considered specific to honey bees, are suspected of spilling over from managed honey bees into wild bumble bee populations. To test this, I collected bees and flowers in the field from areas with and without honey bee apiaries nearby. Prevalence of deformed wing virus (DWV) and black queen cell virus (BQCV) as well as replicating DWV infections in Bombus vagans and B. bimaculatus were highest in bumble bees collected near honey bee apiaries (χ 12 < 6.531, P < 0.05). My results suggest that honey bees are significant contributors of viruses to bumble bees. Flowers have been suspected as bridges in virus transmission among bees. I detected bee viruses on 18% of the flowers collected within honey bee apiaries and detected no virus on flowers in areas without apiaries, thus providing evidence that viruses are transmitted at flowers from infected honey bees. In controlled experiments using captive colonies in flight cages, I found that honey bees leave viruses on flowers but not equally across plant species. My results suggest that there are differences in virus ecology mediated by floral morphology and/or pollinator behavior. No bumble bees became infected in controlled experiments, indicating that virus transmission through plants is a rare event that is likely to require repeated exposure. The few studies examining viruses in bumble bees are generally limited to virus detection, resulting in little understanding of the conditions affecting virus titers. In honeybees, infections may remain latent, capable of replicating under certain conditions, such as immunosuppression induced by pesticide exposure. I tested whether exposure to imidacloprid, a neonicotinoid pesticide, affects virus titers in bumble bees. In previous honey bee studies, imidacloprid exposure increased virus titers. In contrast, I found that bumble bee exposure to imidacloprid decreased BQCV and DWV titers (χ42 < 20.873, p < 0.02). My findings suggest that virus-pesticide interactions are species-specific and results from honey bee studies should not be generalized across other bee species. Having found that honey bees are significant contributors of viruses to wild bees and flowers, I investigated how honey bee management practices affect disease spread and developed recommendations and tools to lesson the risk of spillover events. Honey bee disease may be exacerbated by migratory beekeeping which increases stress and opportunities for disease transmission. I experimentally tested whether migratory conditions contribute to disease spread in honey bees and found negative yet varying effects on bees suggesting that the effects of migratory practices may be ameliorated with rest time between pollination events. State apiary inspection programs are critical to controlling disease spread and reducing the risk of spillover. However, these programs are often resource constrained. I developed and deployed a toolkit that enables state programs to prioritize inspections and provide a platform for beekeeper education. Using novel data collected in Vermont, I discovered several promising avenues for future research and provided realistic recommendations to improve bee health.

The small hive beetle (Aethina tumida Murray) is an endemic scavenger in colonies of honey bee (Apis mellifera L.) subspecies inhabiting sub-Saharan Africa. The beetle only occasionally damages host colonies in its native range and such damage is usually restricted to weakened/diseased colonies or is associated with after absconding events due to behavioral resistance mechanisms of its host. The beetle has recently been introduced into North America and Australia where populations of managed subspecies of European honey bees have proven highly susceptible to beetle depredation. Beetles are able to reproduce in large numbers in European colonies and their larvae weaken colonies by eating honey, pollen, and bee brood. Further, adult and larval defecation is thought to promote the fermentation of honey and large populations of beetles can cause European colonies to abscond, both resulting in additional colony damage. The economic losses attributed to the beetle since its introduction into the United States have been estimated in millions of US dollars. Although beetles feed on foodstuffs found within colonies, experiments in vitro show that they can also complete entire life cycles on fruit. Regardless, they reproduce best on diets of honey, pollen, and bee brood. After feeding, beetle larvae exit the colony and burrow into the ground where they pupate. Neither soil type nor density affects a beetle’s ability to successfully pupate. Instead, successful pupation appears to be closely tied to soil moisture. African subspecies of honey bees employ a complicated scheme of confinement (aggressive behavior toward and guarding of beetles) to limit beetle reproduction in a colony. Despite being confined away from food, adult beetles are able to solicit food and feed from the mouths of their honey bee guards. Remarkably, beetle-naïve European honey bees also confine beetles and this behavior is quantitatively similar to that in African bees. If confinement efforts fail, beetles access the combs where they feed and reproduce. Two modes of beetle oviposition in sealed bee brood have been identified. In the first mode, beetles bite holes in the cappings of cells and oviposit on the pupa contained within. In the second mode, beetles enter empty cells, bite a hole in the wall of the cell, and oviposit on the brood in the adjacent cell. Despite this, African bees detect and remove all of the infected brood (hygienic behavior). Similarly, European bees can detect and remove brood that has been oviposited on by beetles. Enhancing the removal rate of infected brood in European colonies through selective breeding may achieve genetic control of beetles. Additional avenues of control were tested for efficacy against beetles. Reducing colony entrances slowed beetle ingress but the efficacy of this method probably depends on other factors. Further, the mortality of beetle pupae was higher when contacting species of the fungus Aspergillus than when not, making biological control an option. Regardless, no control tested to date proved efficacious at the level needed by beekeepers so an integrated approach to controlling beetles remains preferred. The amalgamation of the data presented in this dissertation contributed to a discussion on the beetle’s ecological niche, ability to impact honey bee colonies in ways never considered, and the ability to predict the beetle’s spread and impact globally.

FELIX, Jânio Angelo. Perfil zootécnico da meliponicultura no Estado do Ceará, Brasil. 2015. 79 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Fortaleza-CE, 2015 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-29T13:23:24Z No. of bitstreams: 1 2015_dis_jafelix.pdf: 2358209 bytes, checksum: fbe0a617f77c4042edd3f3c96453f50b (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-29T13:23:46Z (GMT) No. of bitstreams: 1 2015_dis_jafelix.pdf: 2358209 bytes, checksum: fbe0a617f77c4042edd3f3c96453f50b (MD5) / Made available in DSpace on 2016-07-29T13:23:46Z (GMT). No. of bitstreams: 1 2015_dis_jafelix.pdf: 2358209 bytes, checksum: fbe0a617f77c4042edd3f3c96453f50b (MD5) Previous issue date: 2015 / Work with stingless bees are called meliponiculture. It is an sustainable activity which supports the preservation of both bees and environment through pollination services provided to the native plants, as well as increase the income of farmers. The main objective of this work was investigate the currently status of the meliponiculture in Ceara, Brazil. Were interviewed 159 stingless beekeepers who are distributed in whole state. The applied questionnaire has objective and subjective questions, all about their personal, professional and environmental features; meliponary, hives, handling characteristics applied to colonies etc. At the same time were collected specimens of bees from their colonies to accurately identify the kept species. The results were shown by percentage and highlighted that jandaíra bees (Melipona subnitida) is the most common specie kept in the state. Most of the stingless beekeepers still practicing that activity traditionally and the knowledge about meliponines biology and handling sometimes are incipient as much as the handlings are ancient. Were observed that handling practices as artificial feeding are extremely important to maintain and increase of the colonies productivity. The technical training for beekeepers is extremely important to reduce depredatory practices to meliponines, besides improve productivity and teach good manufacturing practices around stingless bees products. The meliponiculture have a huge potential to evolve and is possible to realize a significantly grown on that activity in recent years. In spite of it is needed better support from the government to these stingless beekeepers in form of building or support projects which encourage the activity, the confection of handling plans and environment conservation. / A criação de abelhas sem ferrão, chamada meliponicultura, é uma atividade sustentável que ajuda a preservar as abelhas e o meio ambiente, através do serviço de polinização, prestado às plantas nativas, além de incrementar a renda de agricultores familiares. Objetivou-se com este estudo investigar a situação atual da meliponicultura no Estado do Ceará. Foram entrevistados 159 meliponicultores distribuídos em todas as mesorregiões do Estado. Os questionários aplicados continham perguntas fechadas e abertas, referentes ao perfil dos meliponicultores, características das propriedades onde são criadas as abelhas, bem como meliponários, colméias e características do manejo aplicado às colônias. Concomitantemente, foram coletados espécimes de abelhas das colônias para identificação das espécies criadas. Os resultados foram apresentados em forma de percentual e evidenciam que a jandaíra (Melipona subnitida) é a espécie de abelha sem ferrão mais criada no Estado do Ceará. A maioria dos meliponicultores ainda pratica a atividade de maneira tradicional e o conhecimento sobre a biologia e manejo dos meliponíneos em alguns casos é insipiente. Foi observado que algumas práticas de manejo como a alimentação artificial são muito importantes para manutenção e melhoria da produtividade das colônias. A capacitação técnica dos meliponicultores é de extrema importância para redução de práticas prejudiciais aos meliponíneos, além de melhorar a produtividade e transmitir boas práticas de fabricação dos produtos das abelhas sem ferrão. A meliponicultura apresenta alto potencial para ser desenvolvida no Ceará e vem crescendo nos últimos anos. No entanto, necessita de maior apoio por parte de órgãos governamentais para implementação de projetos que incentivem a meliponicultura, planos de manejo e conservação do meio ambiente.