Bee declines have been reported globally and habitat loss and degradation due to urbanization and agricultural intensification are two of the primary drivers. Native bees play a critical role in plant reproduction, and declines in abundance and diversity of bees are expected to impact flowering plant biodiversity and productivity of insect pollinated agricultural crops. Habitat restoration can help mitigate declines by increasing the amount and quality of available bee habitat. However, outside of agroecosystems bees are rarely specified in restoration targets and little is known about how they respond to habitat restoration. My thesis addresses this knowledge gap by: (1) documenting the structure and function of the native bee community at a restored wet meadow to establish a baseline for future monitoring activities, (2) comparing the influence of two restoration approaches on the established bee community, and (3) exploring changes in functional groups and pollination function with time since restoration. I sampled bees at degraded, restored, and (semi)natural habitats at 12 sites in four locations in southern Ontario. I used a combination of structural (abundance, richness, and evenness) and functional (guilds based on social and nesting habits and plant-pollinator interaction networks) characteristics to describe and compare bee communities. I collected a total of 10,446 bees from 30 genera and six families representing a range of phenologies, social behaviours, and nesting habits. At Dunnville Marsh, a restored wet meadow, I collected 5,010 bee specimens from 27 genera and six families. The bee community at Dunnville Marsh was diverse and well connected within 4-6 years of restoration, emphasizing the importance of wet meadows as native bee habitat. However, wood nesters and cleptoparasites were relatively uncommon suggesting that the community may be less stable compared to older habitats. Between 2005 and 2008, individual fields at Dunnville Marsh were dug with pits and mounds before planting and seeding or were seeded into weedy ground. Digging pits and mounds did not convey a clear advantage to the establishing bee community, but genus richness was greater in pit and mound sites (p=0.04). As well, the restoration approach used influenced the relative representation of guilds within the community. Ground nesters and wood nesters were significantly more abundant in pit and mound treated sites (p<0.001), perhaps reflecting the larger amounts of bare ground (p<0.001) and the greater potential for sapling survival on mound tops. Stem nesters were more abundant in planted sites (p<0.001), and floral richness and abundance did not differ between the two restoration approaches. Finally, diversity and evenness of guilds based on social and nesting habits increased with age since restoration, indicating that communities in (semi)natural habitats are more functionally diverse than those in restored habitats, but that communities in restored habitats are more functionally diverse than those in degraded habitats. Relative abundance of guilds changed with age since restoration in ways that reflected structural habitat changes associated with succession. Degraded sites had the highest relative abundance of ground nesters, while (semi)natural sites had the highest relative abundance of wood nesters. Plant-pollinator interaction networks did not demonstrate clear trends with respect to age since restoration, but indicated that communities that establish in response to non-targeted restorations can be diverse, robust to extinction, and well connected.

Orchids provide a model system for addressing evolutionary and ecological questions both because of their species diversity, and because the packaging of their pollen into pollinia facilitates the estimation of male and female pollination success. This thesis focuses on the ecology and evolution of pollination systems in the African orchid genus Eulophia, with an emphasis on deceptive pollination, mechanisms promoting cross-pollination, and pollinatordriven speciation. Pollination in the deceptive species E. zeyheriana is shown to depend on flower colour and proximity to the rewarding model species, Wahlenbergia cuspidata (Campanulacae). This study demonstrates the functional importance of colour matching between model and mimic in a floral Batesian mimicry system, as well as the importance of facilitation by the rewarding model [chapter 2]. The pollinaria of the vast majority of Eulophia and Acrolophia species undergo reconfiguration following removal by pollinators, similar to the phenomena first described by Darwin in some European orchids and which he hypothesised to be adaptations to limit pollinator mediated self-pollination. In chapter 3, a less common mechanism – anther cap retention – is described for E. foliosa. Observations of reconfiguration times were compared to the respective visit times by pollinators in a number of orchids (including Eulophia and Acrolophia) and asclepiads. In 18 of 19 species, pollinarium reconfiguration times exceed the average visit times, providing empirical support for Darwin’s cross-pollination hypothesis [chapter 4]. All of the 25 species of Eulophia examined are deceptive, but two of the three species in the small, closely related Cape genus Acrolophia examined in chapter 5 are rewarding. This translates into very high levels of pollen transfer efficiency in the rewarding A. cochlearis relative to the deceptive A. capensis and species of Eulophia. In addition, A. cochlearis exhibits high rates of pollinator-mediated self-pollination, as quantified using a novel method based on levels of inbreeding depression during embryo development. In chapter 6 the evolutionary divergence of long- and short-spurred forms of E. parviflora in response to different pollinators is investigated. This shows that divergence has occurred in floral morphology, scent chemistry and flowering phenology and that this can be attributed to adaptations to the respective bee and beetle pollinators of each form. This thesis also includes case histories of bee pollination in an additional five Eulophia species, and beetle-pollination in two other species of Eulophia with dense inflorescences and slow pollinarium reconfiguration [chapter 7]. In addition, four taxa were found to undergo auto-pollination [chapter 8]. The main conclusions of this thesis are that pollination of food-deceptive species can be enhanced by spatial proximity to, and floral colour matching with, sympatric rewarding species; that selection strongly favours traits that promote cross-pollination; that pollinatorshifts can drive speciation; and that floral adaptations for bee-, beetle-, and auto-pollination are found in South African representatives of Eulophia. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Today traditionally managed wooded hay meadows only exist in small fractions of their former distributions. Because of the fragmentation and degeneration of hay meadows and the fact that pollinating insect diversity and abundance also are declining, pollination services in these habitats requires attention. To examine the pollination services in traditionally managed hay meadows I collected Ranunculus acris (Buttercup) in 20 meadows of varying quality on Gotland and evaluated the mean seed set and mean number of produced seeds per plant. I also collected Filipendula vulgaris (Dropwort) in 18 meadows and evaluated the mean seed set to be able to compare the pollination success of the insect pollinated R. acris with the wind pollinated F. vulgaris. A range of habitat variables were collected in the meadows and in older surveys to examine their relative impact on seed set. I found significantly higher seed set for R. acris in the meadows with higher habitat quality, than in meadows with lower quality. In contrast seed set in F. vulgaris was not related to habitat quality. The population density also seemed to play an important role in fertilization rate for R. acris, through increased seed set in high density areas, while plant height was positively correlated with number of produced seeds. For F. vulgaris seed set was positively correlated with moss cover, and number of seeds per plant was positively correlated with population density. These results suggest that reproductive success among insect pollinated plants are more sensitive to habitat degeneration than among wind pollinated plants. The status of pollination services in traditionally managed wooded hay meadows should be evaluated further.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A pesquisa foi realizada entre os meses de novembro de 2009 a janeiro de 2010, na Chapada do Apodi, em Limoeiro do Norte, no estado do CearÃ. Utilizaram-se, ao todo, 32 Ãrvores de cajazeira (Spondias mombin L.), do clone Lagoa Redonda, enxertado sobre umbuzeiro (Spondias tuberosa Arruda). O trabalho teve como objetivo avaliar a biologia floral, o padrÃo de forrageamento, abundÃncia e freqÃÃncia das abelhas visitantes florais da cajazeira durante todo o perÃodo de florescimento, alÃm do vingamento inicial (fertilizaÃÃo das flores) de acordo com os diferentes testes de polinizaÃÃo (polinizaÃÃo livre, restrita com papel, restrita com filÃ, manual cruzada com o pÃlen oriundo de flores masculinas, manual cruzada com o pÃlen oriundo de flores hermafroditas, autopolinizaÃÃo manual, polinizaÃÃo por abelhas Apis mellifera e polinizaÃÃo por abelhas Trigona spinipes). Os resultados mostraram que os principais e mais abundantes visitantes florais das flores de cajazeira, foram Apis mellifera (68%), Trigona spinipes (30%), Xylocopa grisescens (1%) e Plebeia aff. Flavocincta (1%). A cajazeira possui uma elevada produÃÃo de flores, porÃm os nÃveis de polinizaÃÃo natural estÃo muito abaixo do seu potencial de vingamento de frutos, quando comparados com a polinizaÃÃo cruzada manual e com a polinizaÃÃo por Apis mellifera. As flores da cajazeira nÃo possuem a capacidade de realizar a autopolinizaÃÃo, necessitando da participaÃÃo de agentes abiÃticos, no caso o vento e/ou biÃticos, como as abelhas, para que haja a polinizaÃÃo das flores. Conclui-se que, a cajazeira à uma espÃcie andromonÃica e alÃgama, grande produtora de pÃlen e com sÃndrome de polinizaÃÃo por melitofilia, onde as espÃcies Apis mellifera, Trigona spinipes e Xylocopa grisecens sÃo os seus efetivos polinizadores. Sendo a Apis mellifera, o principal polinizador e o mais eficiente, promovendo incremento no vingamento dos frutos do clone de cajazeira Lagoa Redonda, sob cultivo, na Chapada do Apodi, CearÃ. / The research was carried out from November of 2009 to January of 2010, in the Apodi plateau, situated in the county of Limoeiro do Norte, state of CearÃ. It was used 32 cajazeira trees (Spondias mombim L.) of the Lagoa Redonda cloning tree, grafted on the umbuzeiro tree (Spondias tuberose A.). The objective was to verify some variables regarding to floral biology; foraging pattern; abundance and frequency of floral visitors, mainly bees, of the cajazeira tree during the blooming season. It was also observed the initial fruit set for each pollination test (open pollination; restricted pollination with a paper pollination bag; restricted with a tulle pollination bag; hand cross pollination with pollen from males flowers; hand cross with pollen from hermaphrodite flowers; autopollination and pollination by honeybee, Apis mellifera and stingless bee, Trigona spinipes). The results showed that the main and most abundant floral visitors of the cajazeira tree were A. mellifera (68%) followed by T. spnipes (30%), Xylocopa grisescens (1%) and Plebeia aff. Flavocincta (1%). Although the cajazeira tree presents high production of flowers, the levels of open pollination are below to its potential of setting fruits, when compared with the hand cross-pollination and with the pollination by Apis mellifera. The flowers of cajajeira tree are unable to do self-pollination, thus requiring the participation of abiotic agents, in this case the wind, and/or biotic agents like bees, to promote their pollination. It is concluded that the cajazeira tree, is an andromonoecious, and allogamous species which produces high amount of pollen, and presents a melittophilous pollination syndrome whose the species Apis mellifera, Trigona spinipes and Xylocopa grisecens are its effective pollinators. Among them, Apis mellifera was the main, and the most efficient pollinator, which improved the initial fruit set on the Lagoa Redonda cloning tree, under cultivation conditions, in the Apodi plateau, state of CearÃ.

My study focuses on how the pollination frequence for wild insect pollinators was influenced by the presence of honey bees. Man made beehives, with their thousands of honey bees, can potentially affect wild insect pollinators within 3 km radius. Several studies indicate that this competition will be disadvantageous for wild insect pollinators. The study at hand was conducted in boreal areas of North Swedens southern coastal region. In each area studied, the frequency of pollinators, wild as well as domesticated, was counted in close proximity to beehives and at reference areas, distanced more than 3 kilometres from nearest hive. The reults are somewhat startling, but not statistically significant. In five of the six sites, the wild pollinators were more numerous with honey bees present.

Pollination syndromes refer to stereotyped floral characteristics (flower colour, shape, etc.) that are associated with a functional group of pollinators (bee, bird, etc.). The trumpet creeper Campsis radicans, endemic to the southeast and mid-west United States, has been assigned to the hummingbird-pollination syndrome, due mainly to its red, trumpet-shaped flowers. Previous studies demonstrated that the ruby-throated hummingbird Archilochus colubris is C. radicans' primary pollinator, but anecdotal data suggest various bee species may provide pollination service when hummingbirds are absent. This study characterised C. radicans nectar volume and concentration by time of day. Nectar volume was suitable for hummingbirds, but concentration was higher than typical hummingbird-pollinated plants (∼20% w/w); at ∼30% w/w, it approached the concentration expected in bee-pollinated plants (∼50% w/w). We also found substantial amounts of nectar at night. Two C. radicans populations received virtually no hummingbird visits, but the number of bees were markedly higher than in the populations previously described. Interestingly, there were no night-time visitors despite the large quantity of nocturnal nectar. Based on previously published pollen delivery per visit by various species, this study estimated that cumulative deposition by bees routinely reached pollen deposition thresholds for setting fruit in C. radicans. They are, unequivocally, the predominant pollinators in these populations, thus providing pollination service in the absence of hummingbirds. These results highlight C. radicans as a food source for native bees and add to the understanding of how floral phenotypes can facilitate pollination by disparate functional groups.

No description available.

Declines in pollinators around the globe, notably the loss of honey bees (Apis mellifera L.) to Colony Collapse Disorder, coupled with a dearth of quantitative data on non-Apis bee pollinators, led to this dissertation research, which documents the role of non-Apis bees in crop pollination in southwest Virginia. Major findings of this first study of its kind in the region were that non-Apis bees provided the majority of pollination—measured by visitation—for several economically important entomophilous crops (apple, blueberry, caneberry, and cucurbits); diverse bee populations may be helping to stabilize pollination service (105 species on crop flowers); landscape factors were better predictors of non-Apis crop pollination service than farm management factors or overall bee diversity; and non-Apis bees in the genera Andrena, Bombus, and Osmia were as constant as honey bees when foraging on apple. Non-Apis, primarily native, bees made up between 68% (in caneberries) and 83% (in cucurbits) of bees observed visiting crop flowers. While 37–59 species visited crop flowers, there was low correspondence between bee communities across or within crop systems ("within crop" Jaccard similarity indices for richness ranged from 0.12–0.28). Bee community diversity on crop flowers may help stabilize pollination service if one or more species declines temporally or spatially. A few species were especially important in each crop: Andrena barbara in apple; Andrena carlini and A. vicina in blueberry; Lasioglossum leucozonium in caneberry; and Peponapis pruinosa and Bombus impatiens in cucurbits. Eight species collected were Virginia state records. In models testing effects of farm management and landscape on non-Apis crop pollination service, percent deciduous forest was positively correlated in apple, blueberry, and squash, but at different scales. For apple and blueberry, pollination service declined with an increase in utilized alternative forage but was positively related to habitat heterogeneity. For squash, percent native plants also related positively, possibly due to increased presence of bumble bees in late summer. Species collected from both bowl traps and flowers was as low as 22% and overall site bee diversity had no effect on crop pollination service, highlighting the value in pollination research of monitoring bees on flowers. / Ph. D.

The populations of wild pollinators have been declining worldwide, mainly due to habitat loss or change. Some farmers use honeybees to secure pollination of their crops, but honeybees can cause further problems effecting wild pollinators. Knowledge of foraging plants for honeybees can give a clue to the conditions of interactions and competition between honeybees and wild pollinators. The aim of this study was to identify plants visited by honeybees, and to compare classic morphological methods of identifying pollen to other modern palynological techniques. Samples of bee pollen from two hives in Västerbotten county, Sweden, was studied with light microscope. A selection of the samples were also studied in scanning electron microscope or by extraction of nucleic acid followed by PCR. All the identified pollen types originated from plants common in Sweden, for example, raspberry, rosebay willowherb, member of the genus Vaccinium and different types of clover. Due to similar morphology, many of the pollen types had more than one possible origin. Many types of pollen found in the samples remained unidentified. Regarding modern palynological techniques, one grain of bee pollen was substantial to extract enough nucleic acid to perform PCR. Positive PCR reactions were found for all but one of the seven PCR primers tested. Each primer gave positive reaction to only one color of bee pollen. One of the colors of bee pollen did not give any positive PCR reaction. The result of this study highlights the further need of reliable and available reference material in the palynological field.

Yes / In this paper, a new population-based and nature-inspired metaheuristic algorithm, Discrete Flower Pollination Algorithm (DFPA), is presented to solve the Resource Constrained Project Scheduling Problem (RCPSP). The DFPA is a modification of existing Flower Pollination Algorithm adapted for solving combinatorial optimization problems by changing some of the algorithm's core concepts, such as flower, global pollination, Lévy flight, local pollination. The proposed DFPA is then tested on sets of benchmark instances and its performance is compared against other existing metaheuristic algorithms. The numerical results have shown that the proposed algorithm is efficient and outperforms several other popular metaheuristic algorithms, both in terms of quality of the results and execution time. Being discrete, the proposed algorithm can be used to solve any other combinatorial optimization problems. / Innovate UK / Awarded 'Best paper of the Month'