Download or read book Assessing the Impact of Super Abundant Non native Honey Bees Apis Mellifera on Native Plants and Pollinators written by Dillon Joseph Travis and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nestled in the California Floristic Provence, a biodiversity hotspot, San Diego County is home well over 2,500 species of plants and at least 650 bee species, many of which are endemic to the region. Despite the great diversity of pollinators like bees, non-native honey bees (Apis mellifera) make up greater than 70% of all visits to native plants in habitat. Lacking a baseline of pollinators populations and plant reproduction before the arrival of honey bees in the 1800s, the impact of this super abundant non-native species is not well known. In this dissertation, I take an applied and exploratory perspective to study and better understand the effects of honey bees on native plants and pollinators. In the first chapter, I demonstrate that honey bee pollination of native plants leads to decreased fitness of both the parent and progeny generations of three common native plants. In the second chapter, I determine if geitonogamous visitation by honey bees is a conserved behavior throughout its global range by reviewing peer reviewed manuscripts containing relevant information. In the third chapter I quantified the mass of pollen removed by honey bees daily from multiple study sites and estimated the number of native bees of average size that could have been produced with this pollen, and the mass of native bees that could be produced by directly converting observed honey bee biomass into native bees. Finally, in the fourth chapter I set out to determine if honey bees negatively impact native pollinator populations by comparing native pollinator diversity and abundance both in the presence and absence of honey bees using Santa Cruz Island where honey bees have been eradicated, and the Santa Monica Mountains where honey bees persist. Altogether, this work reveals the stunning impact honey bees have on both native plants and pollinators in San Diego County and Southern California. I hope that this dissertation can be used to inform conservationists and policy makers about the impacts of honey bees on our native plants and pollinators so that they may be preserved for generations to come.
Download or read book Investigating the Potential Negative Impacts of Managed Honey Bees Apis Mellifera on Native New Zealand Plant pollinator Communities written by Freya Jackson and published by . This book was released on 2019 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interactions formed between plants and their animal pollinators play a valuable role in maintaining ecological integrity and sustaining ecosystem function. The introduction of an exotic pollinator may disrupt native plant-pollinator. Worldwide, there is contradictory evidence as to whether honey bees cause changes to the diversity and abundance to new pollinator communities, changes to native pollinator foraging behaviour, and/or consequences to plant reproductive success. The relative impact of honey bees is likely to depend on the behavior and guilds of native bees, changes in habitat availability and seasons. The impact of introduced honey bees is likely to be greater on small and remote oceanic islands with high levels of endemism, such as Aotearoa New Zealand. Given the widespread occurrence of honey bees in New Zealand, and recent increases in bee keeping, the impacts on native plants and pollinators need to be addressed. The objective of my study was to explore the potential negative impacts of honey bees on native New Zealand plant-pollinator communities. Using a comparative observational approach as well as some field manipulations and molecular analyses, I surveyed pollinator behavior, pollination processes, and plant fitness for two widespread and taonga plants, pōhutukawa and kānuka at three different sites across New Zealand, two with honey bees (Thames and Waiheke Island), and one without honey bees (Great Mercury Island). The widespread distribution of honey bees in New Zealand makes finding study sites without bees but with comparable plants very difficult. First, I examine interspecific (between pollinator species) and intraspecific (between individuals of one pollinator species) differences in foraging behaviour, and floral resource preferences between introduced honey bees and native solitary bees to gauge the potential for competition. Negative impacts on native pollinators was also assessed by measuring the body size of native bees across the three different study sites. Second, I compared the quality and quantity of pollen on the stigmatic surface, number of pollen tubes in the style, and number of seeds within a capsule to explore questions relating to plant reproductive success in the presence of honey bees. DNA metabarcoding techniques were used to assess pollen loads carried by both honey bees and native pollinator species. Overall pollinator body size, diversity and abundance was significantly lower in sites where honey bees are present. Specifically, the diversity of pollinators visiting pōhutukawa was significantly lower at Waiheke Island than Great Mercury Island. Honey bees are poor pollinators of pōhutukawa and their dominance at Waiheke also resulted in lower conspecific pollen deposition on stigmas, lower numbers of pollen tube in the style, which correlated with reduced pōhutukawa seed set. Kānuka was pollinated almost exclusively by native bees, and there was higher pollination rates on Waiheke. This is likely due to increased intraspecific competition between Leioproctus imitatus on Waiheke Island, resulting in higher delivery of conspecific pollen to the stigmas, increased number of pollen tubes in the style, and higher reproductive success. Results from pollen DNA analyses also demonstrate honey bees’ preference for pōhutukawa, but also exotic plants in the families Apiaceae, Asteraceae, and Fabaceae. There was a significant difference in the quality and quantity of pollen carried by different pollinators. Pollen loads carried by honey bees reflected their preferences for exotic plants. Out of all the native insects, native Leioproctus carried larger pollen loads consisting of higher proportion of conspecific pollen relative to the plants that they were observed visiting. The species richness of the pollen carried by Leioproctus were significantly lower in sites where honey bees are present, especially for exotic pollen from Asteraceae. This suggests there is competition between Leioproctus and honey bees for highly rewarding exotic plant species, which may explain the observed reduced native bee body size where honey bees are present. In order to limit the potential impact of honey bees on native plant-pollinator, I urge land managers to consider site specific attributes such as conservation status of resident plant and pollinator community and flowering peak period when making decisions regarding bee hive placement. The introduction of honey bees to small offshore islands that offer refugia to from mainland threats (such as Great Mercury Island) should be discouraged.
Download or read book Status of Pollinators in North America written by National Research Council and published by National Academies Press. This book was released on 2007-04-13 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pollinators-insects, birds, bats, and other animals that carry pollen from the male to the female parts of flowers for plant reproduction-are an essential part of natural and agricultural ecosystems throughout North America. For example, most fruit, vegetable, and seed crops and some crops that provide fiber, drugs, and fuel depend on animals for pollination. This report provides evidence for the decline of some pollinator species in North America, including America's most important managed pollinator, the honey bee, as well as some butterflies, bats, and hummingbirds. For most managed and wild pollinator species, however, population trends have not been assessed because populations have not been monitored over time. In addition, for wild species with demonstrated declines, it is often difficult to determine the causes or consequences of their decline. This report outlines priorities for research and monitoring that are needed to improve information on the status of pollinators and establishes a framework for conservation and restoration of pollinator species and communities.
Download or read book Honey Bees written by James Devillers and published by CRC Press. This book was released on 2002-02-21 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Honey Bees: Estimating the Environmental Impact of Chemicals is an updated account of the different strategies for assessing the ecotoxicity of xenobiotics against these social insects, which play a key role in both ecology and agriculture. In addition to the classical acute laboratory test, semi-field cage tests and full field funnel tests, new te
Download or read book Experimental Removal of an Introduced Pollinator Reduces Reproductive Success of California Native Clustered Tarweed written by Annika Joy Nabors and published by . This book was released on 2015 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Honey bees (Apis mellifera), introduced worldwide by humans, are often a numerically dominant pollinator in non-managed ecosystems, but surprisingly few experimental studies have examined the effect of honey bee visitation on wild plant reproduction. I experimentally removed honey bees from plots of clustered tarweed (Deinandra fasciculata: Madiinae), a native annual forb, to measure the contribution of Apis visitation to tarweed seed set. While removal of Apis did reduce seed set, their much higher rate of visitation suggests that honey bees contribute modestly to seed set compared to non-Apis pollinators. Visits by non-Apis visitors significantly increased when Apis was removed, indicating possible competition betwee Apis and other insects. In ecosystems where honey bees become numerically dominant, they can contribute a significant proportion of visits to native plants. Apis removal may negatively affect plant reproduction, especially during years in which native pollinators are relatively uncommon because of lack of floral resources, but it may also release native pollinators from competitive displacement.
Download or read book Competitive Interactions Between the Invasive European Honey Bee and Native Bumble Bees written by Diane M. Thomson and published by . This book was released on 2001 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Community Effects of Introduced Honeybees apis Mellifera on Native Bee Fauna and Plant Pollination Australia written by Guinnevere Ellen Roberts and published by . This book was released on 2001 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing the Ability of Habitat Enhancements in Agricultural Fields to Support Native Bee Nesting Foraging and Ecosystem Services written by Hillary Sardiñas and published by . This book was released on 2015 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop pollination is an essential ecosystem service predominantly provided by honey bees and native bees. The decline of honey bees due to a variety of maladies, including Colony Collapse Disorder, has prompted increased interest in unmanaged pollinators. Native bees are effective pollinators, but they have specific habitat requirements, namely floral and nesting resources, that can limit their distribution in agricultural landscapes. This dissertation examines how floral availability and nesting habitat influence pollinator communities and pollination services from native bees. Increasing floral diversity and abundance has been shown to increase native bee richness and abundance, therefore field-scale habitat enhancements, such as hedgerows, have been proposed as a way to attract and support native bee populations. Whether native bees also visit adjacent crop fields, heightening yields, is less well known. I assess the contribution of native bees visiting hedgerows to seed set in cultivated sunflower, a mass-flowering pollinator-dependent crop (Ch. 1). I find that while sunflower specialist bees (bees that forage exclusively on sunflower) are increased in hedgerow plantings, crop pollination in fields adjacent to hedgerows is not increased. Wild bees, however, both directly and indirectly contribute to sunflower seed set though higher richness and through interactions with honey bee crop visitors. Factors influencing nest-site selection are less well understood, particularly at the community level. Nest locations are challenging to find; therefore proxies have emerged as a means of correlating potential resources to bee species present in a study area. This approach may overestimate nesting bees; therefore I test a method to randomly sample bee nesting using emergence traps, then determine whether nesting proxies correlate to nesting rates (Ch. 2). Emergence traps are effective at capturing bees in their nests. When I compare bees collected in emergence traps to the community of bees found visiting within site floral resources, I see distinct differentiation between the species collected, indicating that bees foraging within a location may not be nesting there. I find that some proportion of bare ground and variability in slope are strongly correlated to nesting incidence and abundance. I use the emergence trap technique to examine whether hedgerow field-margin enhancements increase nesting resources and subsequent nesting incidence (Ch. 3). While many nesting resources are elevated in hedgerow plantings, I find that this does not translate into increased rates of nesting. This could be attributable to the low site coverage provided by emergence traps, or could indicate that the nesting proxies I am evaluating are not strongly indicative of nesting quality. Models of pollination services in agricultural landscapes estimate floral and nesting resources. These parameterizations are combined with pollinator foraging ranges to generate predictions of pollination coverage. Nesting suitability is primarily based on expert opinion, which in past studies limited potential nest site availability to field margins. I test this assumption in Ch. 4 by sampling with emergence traps in sunflower fields and along field edges. I then combine this nesting data with direct measurements of foraging distances to simulate pollination within a single crop field. I find that while some bees nest directly within crop fields, in the presence of a mass-flowering crop they only forage a small fraction of their foraging range. Pollination services are thus centralized around nest locations. While increasing floral resources is important for sustaining native bee populations, I do not find a strong effect of hedgerow restorations on pollination of adjacent crops or on nesting resources. Hedgerows may be more effective in different crop or landscape contexts. Because selected bees nest within crop fields, focusing on management of cropped areas, not just field edges, will likely benefit native bees in agricultural landscapes. In order to sustain pollinator populations and maintain agricultural yields, I suggest incorporating multiple methods of diversification into agricultural landscapes.
Download or read book The Pollen Foraging Ecology of Honey Bees Apis Mellifera in a Fragmented Environment written by Byeong Hon Park and published by . This book was released on 2012 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Honey bees recruit foragers to rich food sources through the waggle dance. The waggle dance has been used extensively to study the foraging ecology of honey bees in various habitats. We decoded waggle dances and used DNA barcoding of bee-collected pollen to characterize the foraging ecology of honey bees Apis mellifera L.) over 17 months around La Jolla, California, a heavily fragmented environment containing urban, semi-urban, and patches of native scrub habitats. We divided the year into three distinct seasons (dormant, growth, and dry) based on natural patterns of warming and rainfall to understand how honey bee foraging varies over ecologically relevant temporal scales in a fragmented environment. We detected a significant effect of season on foraging distances. We also found that colonies focused their foraging efforts on few patches during the dormant season and performed increasingly wider searches for pollen with changes in season. Lastly, we detected significant seasonal turnover in the proportion of pollen loads with native or non-native pollen. Bees focused their pollen foraging on native species during the dormant season; both native and non-native species during the growth season; and, non-native species during the dry season. Our results show that honey bees are capable of adjusting their foraging behavior with season to exploit common, abundant native and non-native flowers, illustrating the remarkable adaptability of honey bees in fragmented habitats. Furthermore, our study indicates that honey bees may serve as pollinators of common native plants in light of declines in native pollinators bought on by habitat fragmentation.
Download or read book The Impact of the European Honey Bee Apis Mellifera on Australian Native Bees written by Dean Paini and published by . This book was released on 2004 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European honey bee (Apis mellifera) has been present in Australia for approximately 150 years. For the majority of that time it was assumed this species could only be of benefit to Australia‘s natural ecosystems. More recently however, researchers and conservationists have questioned this assumption. Honey bees are an introduced species and may be affecting native fauna and flora. In particular, native bees have been highlighted as an animal that may be experiencing competition from honey bees as they are of similar sizes and both species require nectar and pollen for their progeny. Most research to date has focused on indirect measures of competition between honey bees and native bees (resource overlap, visitation rates and resource harvesting). The first chapter of this thesis reviews previous research explaining that many experiments lack significant replication and indirect measures of competition cannot evaluate the impact of honey bees on native bee fecundity or survival. Chapters two and four present descriptions of nesting biology of the two native bee species studied (Hylaeus alcyoneus and an undescribed Megachile sp.). Data collected focused on native bee fecundity and included nesting season, progeny mass, number of progeny per nest, sex ratio and parasitoids. This information provided a picture of the nesting biology of these two species and assisted in determining the design of an appropriate experiment. Chapters three and five present the results of two experiments investigating the impact of honey bees on these two species of native bees in the Northern Beekeepers Nature Reserve in Western Australia. Both experiments focused on the fecundity of these native bee species in response to honey bees and also had more replication than any other previous experiment in Australia of similar design. The first experiment (Chapter three), over two seasons, investigated the impact of commercial honey bees on Hylaeus alcyoneus, a native solitary bee. The experiment was monitored every 3-4 weeks (measurement interval). However, beekeepers did not agist hives on sites simultaneously so measurement intervals were initially treated separately using ANOVA. Results showed no impact of honey bees at any measurement interval and in some cases, poor power. Data from both seasons was combined in a Wilcoxon‘s sign test and showed that honey bees had a negative impact on the number of nests completed by H. alcyoneus. The second experiment (Chapter 5) investigated the impact of feral honey bees on an undescribed Megachile species. Hive honey bees were used to simulate feral levels of honey bees in a BACI (Before/After, Control/Impact) design experiment. There was no impact detected on any fecundity variables. The sensitivity of the experiment was calculated and in three fecundity variables (male and female progeny mass and the number of progeny per nest) the experiment was sensitive enough to detect 15-30% difference between control and impact sites. The final chapter (Chapter six) makes a number of research and management recommendations in light of the research findings.
Download or read book For Nonnative Crops written by Karen Strickler and published by . This book was released on 2003 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Forgotten Pollinators written by Stephen L. Buchmann and published by Island Press. This book was released on 2012-06-22 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consider this: Without interaction between animals and flowering plants, the seeds and fruits that make up nearly eighty percent of the human diet would not exist. In The Forgotten Pollinators, Stephen L. Buchmann, one of the world's leading authorities on bees and pollination, and Gary Paul Nabhan, award-winning writer and renowned crop ecologist, explore the vital but little-appreciated relationship between plants and the animals they depend on for reproduction -- bees, beetles, butterflies, hummingbirds, moths, bats, and countless other animals, some widely recognized and other almost unknown. Scenes from around the globe -- examining island flora and fauna on the Galapagos, counting bees in the Panamanian rain forest, witnessing an ancient honey-hunting ritual in Malaysia -- bring to life the hidden relationships between plants and animals, and demonstrate the ways in which human society affects and is affected by those relationships. Buchmann and Nabhan combine vignettes from the field with expository discussions of ecology, botany, and crop science to present a lively and fascinating account of the ecological and cultural context of plant-pollinator relationships. More than any other natural process, plant-pollinator relationships offer vivid examples of the connections between endangered species and threatened habitats. The authors explain how human-induced changes in pollinator populations -- caused by overuse of chemical pesticides, unbridled development, and conversion of natural areas into monocultural cropland-can have a ripple effect on disparate species, ultimately leading to a "cascade of linked extinctions."
Download or read book Ecology and Impact of Perturbations on Native Plant pollinator Systems written by Evan Avers Sugden and published by . This book was released on 1984 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Toxicodynamics of Inert and Alternative Agrochemicals and Their Impacts on Honey Bees written by Julia Fine and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Honey bees (Apis mellifera) are highly valued for the pollination services they provide to agricultural crops, but in recent years, beekeepers have experienced high yearly colony losses. Many researchers now believe that these declines are due in part to the effects of agrochemical pesticide use. However, the majority of pesticide research focuses on the effects of pesticide active ingredients on adult honey bees without consideration for the complexities of real world exposure. Pesticides are applied as formulated products composed of active and inert formulants, and these formulations are often tank mixed with inert adjuvants meant to enhance the spread and penetration of active ingredients. Many inerts are assumed by the US EPA to be biologically inert, despite growing evidence that they are toxic to many non-target organisms. Additionally, assessing the toxicity of agrochemicals to adult bees without consideration for their effects on developing larvae or potential interactions with other environmental stressors does not accurately represent their inherent risks. This dissertation explores the effects and environmental fate of chemicals thought to be harmless or of lower risk to bees, including the inert organosilicone adjuvant product, Sylgard 309 (OSS), the inert pesticide formulant N-methyl-2-pyrrolidone (NMP), and the organophosphate alternative, novaluron. These experiments focus primarily on honey bee larvae, which are often overlooked in regulatory risk assessment. First, a study was conducted to investigate the toxicity of OSSs to honey bee larvae when combined with exposure to common viral pathogens such as black queen cell virus (BQCV). This exposure resulted in synergistic mortality related to decreased expression of a Toll-7 homologue and heightened BQCV titers. The dying brood exhibited symptoms similar to those observed in hives used for almond pollination during the 2014 and 2016 seasons. During almond pollination, tank mixes containing OSSs are often applied during bloom, and close proximity of hives from across the United States can facilitate the spread of viral pathogens. Therefore, the study described here represents a real-world scenario likely encountered by many commercial beekeepers. Next, the safety of the insect growth regulator formulation, Rimon 0.83EC to honey bees was assessed. Residue studies in apple orchards were performed to monitor the fate of its active ingredient, novaluron, and its major co formulant, NMP, and the results indicate that NMP is likely to dissipate in the environment before foraging bees come into contact with it, but novaluron residues, which were detected at 3 ppm in pollen 24 hours after application, are more problematic. Concurrently run larval rearing experiments and a nucleus colony study demonstrated that novaluron is highly toxic to honey bee brood. These results suggest that applying novaluron to blooming flowers should be prohibited. Finally, age related differences in tolerances to NMP were investigated. In larval rearing experiments, NMP was chronically toxic to larvae at 100 ppm in diet, while adults are tolerant to significantly higher doses. Honey bees were found to detoxify NMP via a cytochrome P450 mediated pathway, and larvae may be more sensitive to this co-solvent because of a deficit of P450 enzyme activity in the fat body. This finding suggests that larvae may be more sensitive to some xenobiotics than adults, and highlights the importance of considering all members of a hive in honey bee risk assessment. This work seeks to address assumptions in current pesticide regulation and explores the possibility that the use of agrochemicals thought to be inert or lower risk to pollinators may have unintended consequences for honey bee health. By considering multiple variables, including the susceptibility of larvae to agrochemicals, agrochemical environmental fate, and the influence of multiple stressors, these results are easily extrapolated to real-world scenarios and indicate that follow-up studies to characterize the persistence of these chemicals in hive environments are warranted.
Download or read book Assessing Pollinator Friendliness of Plants and Designing Mixes to Restore Habitat for Bees written by Will Glenny and published by . This book was released on 2022 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The worldwide decline in bee populations is threatening the delivery of pollination services, thus leading to the development of pollinator restoration strategies. In the United States, one way to protect and restore bee populations is to use seed mixes composed of pollinator-friendly native plants to revegetate federal lands following disturbance. However, we lack information about which native plant species and mixes are best for bees. We assessed the attractiveness and use by bees of 24 native plant species that are standard for revegetation projects (focal plants) on national forest lands in western Montana. Focal plants that had the highest visitation rate, attracted the most bee species, supported specialist bee species, and bloomed for extended periods across the landscape were considered “pollinator-friendly.” Our results suggest that Salix bebbiana, Arctostaphylos uva-ursi, Lupinus sericeus, Rosa woodsii, Symphoricarpos albus, Erigeron speciosus, Symphyotrichum foliaceum, and Gaillardia aristata could create a seed mix that is effective for pollinator restoration on public lands. Pollinator-friendliness score cards are provided to allow land managers to select plant species to include in restoration mixes that benefit pollinators. Identifying mixes of pollinator-friendly native plant species that are available for restoration will allow land managers to both revegetate disturbed habitats and restore bee communities on federal lands. The methods developed in this project can be used to design seed mixes for pollinator restoration on other public lands.
Download or read book Attracting Native Pollinators written by The Xerces Society and published by Storey Publishing. This book was released on 2011-02-26 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the recent decline of the European honey bee, it is more important than ever to encourage the activity of other native pollinators to keep your flowers beautiful and your grains and produce plentiful. In Attracting Native Pollinators, you’ll find ideas for building nesting structures and creating a welcoming habitat for an array of diverse pollinators that includes not only bees, but butterflies, moths, and more. Take action and protect North America’s food supply for the future, while at the same time enjoying a happily bustling landscape.
Download or read book The Role of Native Bees on Organic Farms in Humboldt County California written by John M. Mola and published by . This book was released on 2014 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: A growing body of literature supports the position that both natural habitat surrounding farms and high flowering crop diversity helps insure farms against pollination shortfalls and an overreliance on European honeybees. I assessed the importance of native pollinators for the ostensibly bee-rich farm habitat of Humboldt County, California (USA). I also evaluated the management potential of an indigenous bee, Osmia lignaria, for orchard crop pollination. I found native bees were less diverse and abundant than expected based on predictions from surveys in other regions on similar crops. The importance of native bees compared to honeybees was especially low on spring crops, and became a little more balanced on summer crops. However, the only two crops where native bees were the main pollinators, squash and tomato, were visited almost exclusively by a single species of bee, and therefore still exhibited an extremely low diversity of pollinators. Studies of O. lignaria showed promising management potential on coastal farms, where their flight season overlapped strongly with orchard bloom and females regularly collected apple pollen. Overall, my study demonstrates that crop pollination may still depend disproportionately on the non-native honeybee, even in areas with high semi-natural habitat in close proximity to farms. Furthermore, the variable importance of native bees across crops and time of season demonstrates that full-season multi-crop studies should be conducted when assessing the role of native bee communities within a region. To safeguard against potential declines in honeybee populations, nesting structures should be deployed on farms to manage local populations of native bee species.
