In the community of Tunshi San Nicols of the Licto parish in the Province of Chimborazo, an evaluation was done on the effect of an energetic supplementary feeding of bees (Italian-mestizas) during the dry season (September 23 to February 20). These supplements consisted of carrot juice (T1), orange juice (T2) and sugar cane juice (T3). These supplements were also compared to a control group (T0). The experimental units consisted of 16 standard beehives distributed randomly with the 4 treatments and 4 repetitions of each treatment. The results showed that sugar cane juice (T3) obtained the best results in the consumption of the supplementary feeding because it was the only treatment where its consumption increased as the nectar sources in the zone decreased. At the end of the evaluation, 17,312.50 ml. of sugar cane juice were consumed. On the other hand, only 1,486.25 ml. of carrot juice were consumed, which was the least amount out of all of the treatments. Similarly, sugar cane juice presented the least weight loss, with 1.050 kg. per beehive. In addition, sugar cane juice also presented the greatest number of breeding frames (6.950 frames per beehive), as well as the best benefit/cost index (1.15) at the end of the study.

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 mite ectoparasite Varroa destructor, poses a serious threat for the survival of the Apis mellifera colonies. The intensive use of acaricidal products is one of the most common methods for defending bees from Varroa that can cause the contamination of the wax foundation used in beekeeping. The natural honeycomb management could provide a solution for this problem, because it involves the use of frames without wax foundation which allows the bees to build a complete comb ex novo. On the other hand, colonies which are free to build cells of their choice, usually build a number of drone cells higher than colonies managed with the wax foundation. This could potentially lead to several negative consequences because the V. destructor reproductive success is greater on drone broods than on worker broods. The aim of the present study was to examine the colony development, to evaluate the honey production and to monitor the growth of V. destructor infestations and associated virus infections in Apis mellifera colonies managed by using natural honeycombs compared with the conventional management. Several colony parameters were measured in spring and summer. The strength of the colony was used to estimate the worker and drone populations. In order to measure the V. destructor infestations were used several methods, such as the natural mite fall, the powdered sugar roll, the soapy water and the brood cell uncapping. Molecular analysis was performed in order to measure the viral load of five Apis mellifera viruses. The honey produced was measured by collecting the honey stored in the supers, which are boxes placed on a beehive for bees to store. The results showed that the higher presence of drone brood in the colonies managed using the natural honeycomb did not negatively affect the colony development nor the mite V. destructor population compared to control colonies. The molecular analysis showed that the DWV was the most common virus found in bee samples, and its viral load was more influenced from the mite infestation rate than from the treatment. The analysis carried out in this study showed that the natural honeycomb management can represent a valid alternative to the wax foundation. This kind of colony management thus appears to contradict our primary hypothesis which was that letting the bees build their own honeycomb would have led to a significant increase in the V. destructor infestation. Productivity data did not provide reliable results about the difference between the natural honeycomb and the conventional colony management due to climatic adversities. Further studies will be performed to better investigate this aspect. Data about the natural mite fall and the estimation of the mite population in the phoretic/reproductive phases provided a useful starting point for further studies on the correct timing to carry out acaricide treatments both in conventional and natural honeycomb managed colonies.

Animal pollination represents one of the key innovations of the flowering plants, and constitutes an essential ecological service in most ecosystems. While pollinators are the main drivers of flower evolution, some floral traits are puzzling when viewed only in the context of this mutualistic interaction. In particular, the pollen of plants belonging to several families has spines or compounds with toxic effects on insects. Little is known about the causes and consequences of these enigmatic floral traits. Yet, pollen defences might play an important role in pollination given that pollen is the main source of food of the principal pollinators in most ecosystems: bees. My thesis investigates why plants sometimes have seemingly defended pollen and how these putative defences affect host-plant use by bees. Given the potential role of flower-colonizing microbes in pollination, I also investigate the potential for these microorganisms to influence flower evolution. I found that pollinators are unlikely to act as potential agents of selection on the concentration of defence compounds in the pollen of Lupinus argenteus. Rather, physiological spillover or pleiotropy from tissues highly defended against herbivores might be responsible for a baseline level of defence compounds in pollen, while such compounds could also mediate the interaction between plants and pollen-colonizing microbes. However, I did not find evidence that flower-colonizing microbes drive the evolution of floral traits in an experimental study. I also found that pollen chemical and mechanical defences likely restrict pollen-host use by Osmiini, a group of solitary bees exhibiting high interspecific variability in their pollen diet. Bees tolerated the defences of their pollen hosts, but were often harmed by the pollen defences of co-occuring plants exploited by other Osmiini species. This pattern provides a striking parallel with the evolution of host-use in herbivorous insects feeding on vegetative tissues, and suggests that pollen defences might play an important role in structuring plant–bee interactions. Overall, my thesis contributes to our understanding of the causes of the presence of chemical defences in pollen and their consequences for the pollination mutualism.

Reports of declining insect populations suggest that more research focusing on this phenomenon is needed, especially in pollinator insects. Climate change, habitat destruction, and usage of certain pesticides have all been implicated in insect decline. Neonicotinoid pesticides are highly toxic to bees, can have drastic sub-lethal effects on behavior, and are persistent in the environment; likewise, they have been implicated as a major factor affecting bee populations. However, there are limited studies on native bees regarding their interactions with neonicotinoids, even regarding simple questions such as exposure levels. In this study, we aimed to assess concentrations of common neonicotinoids in native bees and soils from a threatened habitat in our region, the Black Belt Prairie, by using a modified QuEChERS LC/MS-MS protocol. Our results showed that specific taxa of native bees- Bombus spp., Xylocopa spp., and Mellissodes spp. (Family: Apidae)- were exposed to neonicotinoids. In contrast, no concentration of neonicotinoids was detected in our soil samples.

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This is a project that focuses on building awareness for solitary bees and how we can use public sculptures/artifacts to help and to create a positive vision of the future through art, design,science and to promote bio diversity. A lot of modern techniques like 3D modeling, 3D printing, and CNC milling were used to bring this artifact to life. Public artworks are proven to have a positive effect on our mental health and create discussion, so with this project I wanted to create a public sculpture/artifact that benefits both humans and bees, make sure that people would take notice to it and start to investigate the creation, see all the life that lives around and inside it. This is a form with a function. The material used in this creation will be discarded wood and the wood will decompose with time.  Vacancy focuses on integrating nests for species, in this case solitary bees, within artistic public sculptures and artifacts. Through the creation of this sculpture/artifact, the project aims to engage and inspire the curiosity of the viewer to reflect on the ongoing crisis facing our pollinators. Furthermore, the project aims to promote biological diversity.

No / This study was designed to investigate the nutraceutical potential of monofloral Indian mustard bee pollen (MIMBP). MThe nutritional value of MIMBP was examined in terms of proteins, fats, carbohydrates, and energy value. Its chemical composition in terms of total polyphenol and flavonoid content was determined. MIMBP was screened for free flavonoid aglycones by developing and validating a high-performance liquid chromatography-photo diode array (HPLC-PDA) method. MIMBP was analyzed for in vitro antioxidant effect in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity. MIMBP was found to be comprised of proteins ((182.2+/-5.9) g/kg), fats ((137.7+/-6.8) g/kg) and carbohydrates ((560.6+/-17.4) g/kg), which result in its high energy value ((17 616.7+/-78.6) kJ/kg). MIMBP was found to contain polyphenols ((18 286.1+/-374.0) mg gallic acid equivalent/kg) and flavonoids ((1 223.5+/-53.1) mg quercetin equivalent/kg). The HPLC-PDA analysis revealed the presence of kaempferol ((65.4+/-0.5) mg/kg) and quercetin ((51.4+/-0.4) mg/kg) in MIMBP, which can be used as markers for determining the quality of bee pollen. The MIMBP extract showed DPPH free radical-scavenging activity with a half maximal inhibitory concentration of 54.79 mug/mL. The MIMBP was found to be a rich source of nutrients providing high caloric value, which makes it a candidate for a potential nutraceutical agent. The study also illustrated the high antioxidant content of MIMBP, especially in the principle polyphenols and flavonoids, which suggests its potential role in the prevention of free radical-implicated diseases. The DPPH-scavenging effect of MIMBP further confirmed its antioxidant potential. Additionally, we developed a simple, specific and accurate HPLC-PDA method for the identification and quantification of free flavonoid aglycones. This can be applied in future screenings of the quality of pollen collected by honeybees.

The interaction between Xylocopa californica and Chilopsis linearis was used to test the hypothesis that nectar robbing is costly to plants. No evidence for these costs, either in terms of decreased pollination or increased energy demands, was found. In fact, the mean number of seeds per fruit and the mean individual weight of seeds per fruit was higher from fruits that developed from robbed flowers than from fruits that developed from unrobbed flowers, indicating that the presence of Xylocopa californica enhanced pollination. Chilopsis linearis pollen was isolated from the tips of the abdomens of robbing Xylocopa californica and it was determined that these bees could be transferring pollen from flower to flower as they position themselves to rob. This association was found to be one of mutual benefit rather than one of exploitation.

Bumble bees (bombus spp.) are significant pollinators of many plants, and are particularly attracted to mass-flowering crops such as Oilseed Rape (Brassica Napus), which they cross-pollinate. B. napus is both wind and insect-pollinated, and whilst it has been found that wind is its most significant pollen vector, the influence of bumble bee pollination could be non-trivial when bee densities are large. Therefore, the assessment of pollinator-mediated cross-pollination events could be important when considering containment strategies of genetically modified (GM) crops, such as GM varieties of B. napus, but requires a landscape-scale understanding of pollinator movements, which is currently unknown for bumble bees. I developed an in silico model, entitled HARVEST, which simulates the foraging and consequential inter-patch movements of bumble bees. The model is based on principles from Reinforcement Learning and Individual Based Modelling, and uses a Linear Operator Learning Rule to guide agent learning. The model incoproates one or more agents, or bees, that learn by ‘trial-and-error’, with a gradual preference shown for patch choice actions that provide increased rewards. To validate the model, I verified its ability to replicate certain iconic patterns of bee-mediated gene flow, and assessed its accuracy in predicting the flower visits and inter-patch movement frequencies of real bees in a small-scale system. The model successfully replicated the iconic patterns, but failed to accurately predict outputs from the real system. It did, however, qualitatively replicate the high levels of inter-patch traffic found in the real small-scale system, and its quantitative discrepancies could likely be explained by inaccurate parameterisations. I also found that HARVEST bees are extremely efficient foragers, which agrees with evidence of powerful learning capabilities and risk-aversion in real bumble bees. When applying the model to the landscape-scale, HARVEST predicts that overall levels of bee-mediated gene flow are extremely low. Nonetheless, I identified an effective containment strategy in which a ‘shield’ comprised of sacrificed crops is placed between GM and conventional crop populations. This strategy could be useful for scenarios in which the tolerance for GM seed set is exceptionally low.