In the early twentieth century, Karl von Frisch performed seminal work on the organization of social behavior of honey bees. Much of his work involved training individual foragers to distant artificial feeders. Similar training methods have been used in research laboratories for the better part of a century, and these methods lend themselves well to advanced undergraduate biology classes in animal behavior. In recent years, students have used these methods in group projects to study color preference and time-memory. In this Technical Paper, we describe the basic steps of training honey bees to a distant feeder. We also provide alternative methods for answering specific types of questions that students in animal behavior classes might wish to address.

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.

Anthropogenic landscape changes threaten our ecologically and economically critical honey bees by decreasing the availability of quality foraging resources. Importantly, waggle dance analysis provides a versatile and relatively cost-effective tool for investigating the obstacles that honey bees face, such as habitat loss, in our changing landscapes. While this emerging tool has improved our understanding of honey bee foraging in specific landscape contexts, additional research is needed to identify broad trends that span across landscapes. For this dissertation, I used waggle dance decoding and analysis to investigate honey bee foraging, and sublethal stress responses, across three ecologically distinct landscapes in Virginia. In Chapter 1, I introduce waggle dances as a model study system for investigating honey bee foraging and sublethal stress responses by summarizing modern methodological advances in its analysis and emerging research gaps. In Chapter 2, I tested the effects of sublethal imidacloprid exposure on honey bee foraging and recruitment using a semi-field feeder experiment. In doing so, I report that honey bees decreased their foraging, but not recruitment, to an imidacloprid-laced sucrose solution, compared to a control solution. Together, these effects could potentially harm honey bee health by increasing their exposure to pesticides and decreasing their food intake. In Chapter 3, I compared the foraging distances communicated by waggle dancing nectar and pollen foragers across landscapes to explore the economic forces driving foraging to these resources. I observed higher overall and monthly nectar foraging distances compared to pollen foraging distances. Such results suggest that nectar foraging cost dynamics are driven by supply, while pollen foraging cost dynamics are driven by demand. In Chapter 4, I used waggle dance decoding to map and quantify foraging to agricultural grasslands in a mixed-use landscape. In doing so, I demonstrate that honey bees recruit to agricultural grasslands throughout the season, but that this land type was not more attractive than the broader landscape after correcting for foraging distance, which is a relevant cost that flying bees must consider. Additionally, I qualitatively observe a foraging hot spot, representing high honey bee interest, over a highly heterogenous section of the landscape. The collective results of this chapter identify agricultural grasslands as a potential management target and support the importance of landscape heterogeneity to honey bees/pollinators. In Chapter 5, I used waggle dance decoding to investigate honey bee foraging spatial patterns in the context of optimal foraging theory. In particular, I explore whether co-localized honey bee colonies forage optimally by converging on the same resource patches, or by partitioning the landscape in to distinct foraging territories. Spatial analysis revealed that the colonies widely distributed their foraging at the landscape-scale, with dances from the same and different colonies being similarly distributed, while also establishing distinct, patch-scale, colony-specific, foraging aggregations. Together, these results suggest that the honey bee foraging system produces an emergent foraging pattern that may decrease both within- and among-colony foraging competition. Finally, in Chapter 6, I place my research findings in the context of historical and current trends in honey bee behavioral ecology. Overall, my dissertation improves our understanding of honey bee foraging ecology across landscape contexts using waggle dance analysis, while demonstrating its versatility and effectiveness as a tool for ecologists. / Doctor of Philosophy / Honey bees collect nectar (carbohydrate source) and pollen (protein source) from flowers as their food for survival and reproduction. Human activities, such urbanization, change landscapes and threaten our critically important honey bees by decreasing the availability of flower-rich habitats. Importantly, honey bees share the location of good food sources with their nest mates using a communication behavior called the waggle dance. Interestingly, scientists can estimate the approximate location of the food sources communicated by waggle dancing bees through close observation and cutting-edge analysis. Therefore, we can "decode" honey bees' waggle dances to map their food collection, or foraging, patterns and investigate the obstacles that they face in our changing landscapes. For this dissertation, I used waggle dance decoding and analysis to investigate honey bee foraging across three different landscapes in Virginia. In Chapter 1, I introduce waggle dances as a tool for investigating honey bee behavior by summarizing the modern improvements in its analysis and areas where research is needed. In Chapter 2, I tested the effects of a sublethal exposure to a pesticide, imidacloprid, by observing the foraging and waggle dance behavior of bees visiting feeders with artificial food. I report that honey bees decreased their foraging, but not recruitment, while collecting an imidacloprid-laced sugar solution, compared to a solution without imidacloprid. In Chapter 3, I compared the foraging distances communicated by waggle dancing nectar and pollen foragers across landscapes to explore the economic forces driving foraging to these resources. I observed higher overall and monthly nectar foraging distances compared to pollen foraging distances. Such results suggest that nectar foraging is driven by supply, while pollen foraging is more driven by demand. In Chapter 4, I used waggle dance decoding to map and quantify foraging to agricultural grasslands (pastures and hay fields) in a landscape characterized by diverse land uses. In doing so, I demonstrate that honey bees recruit to agricultural grasslands throughout the season, but that this land type was not more attractive than the broader landscape after correcting for foraging distance. Additionally, I qualitatively observe a foraging hot spot, representing high honey bee interest, over a highly heterogenous section of the landscape. The collective results of this chapter identify agricultural grasslands as a potential management target and support the importance of landscape heterogeneity to honey bees/pollinators. In Chapter 5, I used waggle dance decoding to investigate the spatial patterns of honey bee foraging in the context of optimal foraging theory, which attempts to explain efficient resource collection strategies. In particular, I explore whether neighboring honey bee colonies forage optimally by converging on the same resource patches, or by dividing the landscape in to distinct foraging territories. We found that colonies distributed their foraging widely at the landscape-scale, with dances locations from the same and different colonies being similarly distributed, while also establishing distinct, patch-scale, colony-specific, foraging areas. Together, these results suggest that honey bees use a foraging strategy that decreases both within- and among-colony foraging competition. Finally, in Chapter 6, I place my research findings in the context of historical and current trends in honey bee behavioral ecology. Overall, my dissertation uses waggle dance analysis to improve our understanding of honey bee foraging behavior, while demonstrating its versatility and effectiveness as a tool for ecologists.

To support multiple programming languages, the concept of offering applicationprogramming interfaces (APIs) in multiple programming languages hasbecome commonplace. However, this also brings the challenge of ensuringthat the APIs are equivalent regarding their interface. To achieve this, codeclone detection techniqueswere adapted to match similar function declarationsin the APIs. Firstly, existing code clone detection tools were investigated. Asthey did not perform well, a tree-based syntactic approach was used, where allheader files were compiled with Clang. The abstract syntax trees, which wereobtained during the compilation, were then traversed to locate the functiondeclaration nodes, and to store function names and parameter variable names.When matching the function names, a textual approach was used, transformingthe function names according to a set of implemented rules.A strict rule compares transformations of full function names in a preciseway, whereas a loose rule only compares transformations of parts of functionnames, and matches anything for the remainder. The rules were appliedboth by themselves, and in different combinations, starting with the strictestrule, followed by the second strictest rule, and so fourth.The best-matching rules showed to be the ones which are strict, and are notaffected by the order of the functions in which they are matched. These rulesshowed to be very robust to API evolution, meaning an increase in number ofpublic functions. Rules which are less strict and stable, and not robust to APIevolution, can still be used, such as matching functions on the first or last wordin the function names, but preferably as a complement to the stricter and morestable rules, when most of the functions already have been matched.The tool has been evaluated on the two APIs in King’s software developmentkit, and covered 94% of the 124 available function matches. / För att stödja flera olika programmingsspråk har det blivit alltmer vanligt atterbjuda applikationsprogrammeringsgränssnitt (API:er) på olika programmeringsspråk.Detta resulterar dock i utmaningen att säkerställa att API:erna ärekvivalenta angående deras gränssnitt. För att uppnå detta har kodklonsdetekteringsteknikeranpassats, för att matcha liknande funktionsdeklarationeri API:erna. Först undersöktes existerande kodklonsverktyg. Eftersom de intepresterade bra, användes ett trädbaserat syntaktiskt tillvägagångssätt, där allaheader-filer kompilerades med Clang. De abstrakta syntaxträden, som erhöllsunder kompileringen, traverserades sedan för att lokalisera funktionsdeklarationsnoderna,och för att lagra funktionsnamnen och parametervariabelnamnen.När funktionsnamnen matchades, användes ett textbaserat tillvägagångssätt,som omvandlade funktionsnamnen enligt en uppsättning implementeraderegler.En strikt regel jämför omvandlingar av hela funktionsnamn på ett exakt sätt,medan en lös regel bara jämför omvandlingar av delar of funktionsnamn, ochmatchar den resterande delen med vadsomhelst. Reglerna applicerades bådasjälva och i olika kombinationer, där den striktaste regeln applicerades först,följt av den näst strikaste, och så vidare.De regler som matchar bäst visade sig vara de som är striktast, och som intepåverkas av ordningen på funktionerna i vilken de matchas. Dessa reglervisade sig vara väldigt robusta mot API-evolution, dvs. ett ökat antal publikafunktioner i API:erna. Regler som är mindre strikta och stabila, och interobusta mot API-evolution kan fortfarande användas, men helst som ett komplementtill de striktare och mer stabila reglerna, när de flesta av funktionernaredan har blivit matchade.Verktyget har evaluerats på de två API:erna i Kings mjukvaruutvecklarkit, ochtäckte 94% av de tillgängliga funktionsmatchningarna.

El presente trabajo tuvo como objetivo analizar los recursos nectaríferos y poliníferos utilizados por Apis mellifera en diferentes ecosistemas del Departamento Diamante. Para ello, sobre la base de la distribución florística regional, se seleccionaron 3 apiarios ubicados en zonas de influencia de las comunidades vegetales más representativas, asociadas a diferentes tipos y usos del suelo. A estos apiarios se les realizó un seguimiento anual, registrando sus actividades de recolección de recursos alimenticios; identificando el polen recolectado durante un período apícola y el contenido polínico de la miel producida durante el período apícola, a través de 4 temporadas apícolas (1999-2003). Paralelamente se realizó un estudio de las comunidades vegetales en el área de influencia de cada uno de los apiarios en cuanto a la oferta de recursos melíferos, en diversidad, cobertura-abundancia y período de disponibilidad. Se recolectó material vegetal a fin de conformar una palinoteca de referencia que facilitara la identificación de los tipos polínicos encontrados en los productos elaborados por la abeja. Se analizaron además, muestras provenientes de otros apiarios del departamento, obtenidas en el mismo período, a fin de lograr una caracterización botánica y geográfica más representativa de las mieles producidas en esta región. Se describieron y documentaron 22 tipos polínicos mediante microfotografías tomadas al microscopio óptico y electrónico de barrido. El relevamiento de la vegetación permitió determinar un total de 358 especies, pertenecientes a 83 familias botánicas. Las mejores representadas en diversidad de especies fueron Asteraceae, Poaceae y Leguminosae. Predominaron las especies nativas y herbáceas. El seguimiento de la fenología de 300 especies, permitió establecer la duración de la temporada apícola en la región, la cual se extiende desde agosto a mayo dependiendo de las condiciones meteorológicas. Fueron identificados 105 tipos polínicos en las cargas corbiculares, correspondientes a 41 familias botánicas. Las mejores representadas fueron Asteraceae, Leguminosae y Apiaceae. Los tipos polínicos dominantes en las cosechas corresponden a Salix humboldtiana, Baccharis spp., Rapistrum rugosum, Lotus corniculatus, Glycine max, Prosopis sp., Melilotus albus, Typha latifolia y Ammi visnaga. El promedio de cosecha de polen para la zona fue de 23,6 g/colmena/día. En las mieles, se identificaron 152 tipos morfológicos pertenecientes a 62 familias botánicas. Las mejores representadas en número de especies fueron Asteraceae y Leguminosae. Predominaron las mieles monoflorales (59%). El principal tipo de miel producida fue de Glycine max (21%). Otras mieles obtenidas fueron Lotus corniculatus (15%), “tréboles” (11%), Ammi spp. (5%), Melilotus albus, Salix humboldtiana (3%) y Medicago sativa (1%). Los tipos polínicos más importantes fueron Ammi spp., Lotus corniculatus, Melilotus albus, Glycine max, Brassicaceae, Baccharis spp., Eryngium sp. y Salix humboldtiana. El análisis cuantitativo permitió clasificar al 85% de las mieles en la Clase I y II. Las mieles del Departamento Diamante se caracterizaron por la asociación de polen de Ammi spp., Lotus corniculatus, Melilotus albus, Glycine max, Asteraceae Asteroideae (principalmente especies nativas como Baccharis spp., Solidago chilensis, Eupatorium spp., Bidens spp. y/o Grindelia pulchella) y Salix humboldtiana. / The objective of this research was to analyze the nectariferous and polliniferous resources used by Apis mellifera in different ecosystems of Diamante Department. For this purpose, on the basis of regional floristic distribution, 3 apiaries were selected, located in areas of influence of the most representative plant communities, associated with different types and land uses. These apiaries underwent annual monitoring, recording their activities of collecting food resources, identifying the pollen collected during a beekeeping period and pollen content of honey produced during the beekeeping period, by 4 beekeeping season (1999-2003). In parallel, a study of plant communities in the area of influence of each apiary were realized, for to analyse the supply of resources in diversity, cover-abundance and availability period. Plant material was collected to form a reference palynoteca that facilitate the identification of pollen types found in products manufactured by the bee. Were also analyzed, samples from other apiaries in the Department, obtained in the same period in order to achieve a more representative geographical and botanical characterization of the honey produced in this region. Twenty two pollen types were described and documented by photomicrographs taken of optical microscopy and scanning electron microscopy. The survey of the vegetation allowed to determine a total of 358 species belonging to 83 botanical families. The best represented in variety of species were Asteraceae, Poaceae and Leguminosae. Native and herbaceous species were predominant. The monitoring of the phenology of 300 species, allowed to establish the duration of the beekeeping season in the region, which extends from August to May depending on weather conditions. One hundred and five pollen types were identified in corbicular pollen loads, corresponding to 41 botanical families. The best represented were Asteraceae, Leguminosae and Apiaceae. The dominant pollen types were Salix humboldtiana, Baccharis spp., Rapistrum rugosum, Lotus corniculatus, Glycine max, Prosopis sp., Melilotus albus, Typha latifolia and Ammi visnaga. The average harvest of pollen to the area was 23.6 g/hive/day. In honey, 152 morphological types were identified belonging to 62 botanical families. The best represented in number of species were Asteraceae and Leguminosae. Unifloral honeys were predominant (59%). The main type of honey produced was of Glycine max (21%). Other honeys obtained were Lotus corniculatus (15%), "clover" (11%), Ammi spp. (5%), Melilotus albus, Salix humboldtiana (3%) and Medicago sativa (1%). The most important pollen types were Ammi spp., Lotus corniculatus, Melilotus albus, Glycine max, Brassicaceae, Baccharis spp., Eryngium sp. and Salix humboldtiana. The quantitative analysis allowed to classify the 85% of the honeys in the Class I and II. The honey of Diamante Department were characterized by the association of pollen of Ammi spp., Lotus corniculatus, Melilotus albus, Glycine max, Asteraceae Asteroideae (mainly native species such as Baccharis spp., Solidago chilensis, Eupatorium spp., Bidens spp. and / or Grindelia pulchella) and Salix humboldtiana.

The effects of miticides on the reproductive physiology of queens and drones were examined. The first study examined the effects of Apistan (fluvalinate), Check Mite+ (coumaphos), and Apilife VAR (74% thymol) on sperm production and viability in drones. Drones from colonies treated with each miticide were collected at sexual maturity. Sperm production was determined by counting the number of sperm in the seminal vesicles. Sperm for viability assays was analyzed by dual fluorescent staining. Apilife VAR and coumaphos significantly lowered (P<0.0001) sperm production and coumaphos treatments caused a significant decrease (P<0.0001) in the sperm viability. The effects of miticides on queens was examined by treating queen-rearing colonies and examining the number and viability of sperm in the spermathecae of newly mated queens. Queens from each treatment group were collected after mating and the spermathecae were removed and analyzed. Colonies treated with coumaphos failed to provide viable queens and were excluded. Apilife VAR was found to significantly decrease (P<0.0016) sperm viability. No significant differences in sperm numbers were found between treatments. The effect of miticides on sperm viability over time was also examined. Drones were reared as described, but the spermatozoa were collected as pooled samples from groups of drones. The pooled samples from each treatment were subdivided and analyzed periods of up to 6 weeks. Random samples were taken from each treatment (n = 6 pools) over a period of 6 weeks. The exposure of drones to coumaphos during development significantly reduced sperm viability for all 6 weeks, and caused a large decline in week 6. The potential impacts of these results on queen performance and failure are discussed. / Master of Science in Life Sciences

Host-associated microbial communities, also known as microbiomes, are essential to the health of their hosts, and disturbance of these communities can negatively impact host fitness. The honey bee gut microbiome is a relatively simple host-associated community that makes an excellent model system for studying microbiome stability. In addition, honey bees are essential agricultural pollinators, so factors that impact their health are important for food security. The presented research focused on the stability of the honey bee gut microbiome in response to disturbance from the antibiotic tetracycline. Tetracycline was chosen because it is the most commonly used antibiotic in beekeeping, and may have negative effects on bees through the disruption of their gut microbiomes. The first study presents a new fecal sampling method for studying the honey bee gut microbiome of individual bees over time. This method accurately represented bacterial community structure in the gut microbiome as determined with 16S rRNA gene amplicon sequencing, as fecal and whole gut samples did not differ significantly for individual bees. The fecal sampling technique was then used to examine changes to individual honey bee gut bacterial communities before and after tetracycline exposure. Minimal differences in gut community structure were detected prior to and five days after tetracycline treatment. However, there was variability in how individual gut microbiomes were affected by tetracycline treatment, highlighting the importance of intraspecific variation in response to disturbance. The second study investigated whether the timing of disturbance during a host's life impacts microbiome community stability. Newly emerged bees were treated with tetracycline, returned to their hive, and recollected 7 or 14 days later. The gut communities of the bees were then characterized using 16S rRNA gene amplicon sequencing. Gut microbiome structure of bees treated with tetracycline at emergence differed from controls both 7 and 14 days after emergence, with the antibiotic-treated bees having lower community richness overall. This study showed that early life disturbance of host-associated microbial communities can influence microbiome structure later in life. The final study describes the occurrence of antibiotic resistance genes (ARGs) in honey bee gut bacterial symbionts from hives across the US. Honey bee gut metagenomes were sampled from hives at 13 apiaries located in a transect from Virginia to Washington, and ARG presence was assessed across the sites. We also specifically quantified the abundances of two common tetracycline resistance genes (tet(B) and tet(M)) across apiaries. ARGs, both for antibiotics used in beekeeping and unrelated antibiotics, were detected in honey bee gut bacteria from all apiaries. Tetracycline resistance genes were the most common across all apiaries, and the abundance of two tetracycline resistance genes varied by apiary. Members of the honey bee gut microbiome contained different proportions of ARGs, but taxa within a single family contained similar proportions, possibly indicating phylogeny plays a role in ARG accumulation. In particular, Gilliamella and Frischella, both in the family Orbaceae, contained the highest percentages of ARGs. The results from this study suggest honey bee bacteria act as reservoirs of ARGs. Overall, the presented research contributes to the field of biology by highlighting the importance of intraspecific variation in host-associated microbial communities and presenting a new method for studying honey bee gut microbiome variation at the individual-level, showing that early life events in honey bees influence microbiome development, and suggesting that honey bee bacterial symbionts have adapted to deal with antibiotic disturbance through the accumulation of ARGs. / Doctor of Philosophy / Nearly all animals, including honey bees, have communities of bacteria that live on and in them. These communities, called microbiomes, are often essential to the health of their hosts. For instance, communities of gut bacteria can be important for breaking down food for digestion. Honey bees have approximately 10 bacterial species that consistently live in their guts and provide these types of services to their host. As with many bacterial communities, these beneficial bacteria can be impacted by exposure to antibiotics, even though antibiotics can also be important for treating or preventing dangerous bacterial infections. In honey bee hives, the antibiotic tetracycline is used to prevent bacterial disease. However, tetracycline may simultaneously be negatively impacting colony health through disruption of the honey bee gut microbiome. The goal of the presented work was to understand how tetracycline impacts the honey bee gut microbiome. In my first chapter, I demonstrate a new fecal sampling method that will allow us to understand how gut microbiomes from individual bees change over time. I first compared the bacteria found in fecal samples to those in the whole guts of bees and found that the bacterial communities of the fecal samples and guts were very similar, indicating that fecal sampling is a good method for studying the honey bee gut microbiome. I then used my fecal sampling method to determine how individual honey bee gut microbiomes respond to antibiotic disturbance over time. I collected fecal samples from adult bees prior to treatment, treated the bees with tetracycline, and after five days of being maintained in the lab, recollected fecal samples. My results showed few changes to the bacterial communities before and after treatment, suggesting some honey bee gut microbiomes may be resistant to tetracycline. In my second chapter, I addressed whether exposure to antibiotics early in life had long-term impacts on the gut microbiome. I treated bees at the start of adulthood with tetracycline, returned the bees to their hive for 7 or 14 days, and assessed their microbiome. Tetracycline treatment at the beginning of adulthood changed the gut microbiome later in life, as the microbiomes of tetracycline-treated bees and controls differed from one another both 7 and 14 days after exposure. This chapter shows that disturbances to microbiomes during early life can also affect microbiomes later. My third chapter addressed how honey bee bacteria have adapted to antibiotic use by identifying antibiotic resistance genes (ARGs) in honey bee gut bacteria from 13 hives located in a transect across the US from the state of Washington to Virginia. I found a variety of antibiotic resistance genes in honey bee gut bacteria, both associated with beekeeping and likely environmental contamination. The prevalence of antibiotic resistance genes in honey bee bacteria may help us track antibiotic resistance in the environment. Ultimately, my dissertation contributes to our understanding of how antibiotic use affects honey bees by changing their gut microbiome.

Honey bees, Apis mellifera Linn., provide vital economic and ecological services via pollination while concurrently facing multiple interconnected stressors impacting their health. Many crops like apples, peaches, and cherries that add diversity and nutrition to our diet are wholly or partially dependent upon the pollination services of insects. Orchard crops are self-incompatible and commonly regarded as crops reliant on the pollination services of insects, and while previous studies have focused on the impact of bees to orchard crops during bloom, fewer studies have examined the reciprocal relationship of the orchards on honey bees, particularly across the entire foraging season. Here we investigated the foraging dynamics of honey bees in an orchard crop environment in Northern Virginia, United States. We decoded, mapped, and analyzed 3,710 waggle dances, which communicate the location of a valuable resource in the environment, for two full foraging seasons (April-October, 2018-2019), and, concurrent to the dance filming, collected pollen from returning foragers. We found that bees forage locally the majority of the time (< 2 km) throughout the season, with some long-range distances occurring in May after bloom (both 2018 and 2019) and in fall (2019). The shortest communicated median distances (0.50 km and 0.53 km), indicating abundant food availability, occurred during September in both years, paralleling the bloom of an important late season resource, goldenrod (Solidago). We determined, through plotting and analyzing the communicated forage locations and from the collected pollen from returning foragers, that honey bees forage more within apple orchards after the bloom (29.4% and 28.5% foraging) compared to during bloom (18.6% and 21.4% foraging) on the understory of clover and plantain. This post bloom foraging also exposes honey bees to the highest concentration of pesticides across the entire foraging season (2322.89 ppb pesticides versus 181.8 during bloom, 569.84 in late summer, and 246.24 in fall). Therefore, post bloom apple orchards supply an abundance of forage, but also the highest risk of pesticide exposure, which may have important implications for management decisions of bees in orchards. / Master of Science in Life Sciences / Honey bee hives have been declining significantly in the United States, driven by a multitude of issues and stressors including pesticide exposure, disease, pests such as varroa mites, and poor nutrition caused by natural land being converted into development or agriculture. Agricultural landscapes, in particular, are often monocultures are saturated with pesticides creating a potentially hazardous environment, yet reliant on bees to provide pollination for crops. Because of this interconnected relationship between bees and flowers and the effects of stressors agricultural systems cause have with pollinators, it is necessary to understand how honey bees forage in these environments and what potential health risks they face. We investigated honey bees foraging dynamics in an apple orchard in Northern Virginia, United States by observing honey bee waggle dance behavior, where bees literally waggle back and forth for a certain time and at a certain angle telling their nestmates where a resource is, and collecting pollen from returning forager bees to better understand when, where, and upon what honey bees forage throughout the foraging season, which is when flowers are available and the weather warm enough (April – October). We found that bees mostly forage locally near the hive throughout the season, indicating that sufficient amount of food was available even after short bloom time of the apple (April to mid-May). We determined, through plotting and analyzing the waggle dance locations, that honey bees forage more within apple orchards after the bloom on mostly clover and plantain. This abundance of post bloom foraging also exposes honey bees to the highest amounts of pesticides across the entire foraging season. Post bloom apple orchards supply an abundance of forage, but also the highest risk of pesticide exposure to honey bees.

Yes / Properties of a matter are intrinsically dependent upon the internal arrangement of molecules in the solid state. Therefore, knowledge of 3-dimensional structure of the matter is prerequisite for structure-property correlations and design of functional materials. Over the past century, X-ray crystallography has evolved as a method of choice for accurate determination of molecular structure at atomic resolution. The structural information obtained from crystallographic analysis paved the way for rapid development in electronic devices, mineralogy, geosciences, materials science, pharmaceuticals, etc. Knowledge of the structural information of active pharmaceutical ingredients (APIs) is prerequisite for rational drug design and synthesis of new chemical entities for development as new medicines. Over the past two decades, X-ray crystallography has played a key role in the design of pharmaceutical cocrystals-crystalline solids containing an API and one or more of pharmaceutically acceptable coformers. These materials have proved promising for fine-tuning several important properties of APIs. This short review highlights the history of crystallography, early breakthroughs, and the role of crystallography in understanding physicochemical properties of pharmaceutical cocrystals. / S. Aitipamula gratefully acknowledges the financial support from the Institute of Chemical and Engineering Sciences of A*STAR (Agency for Science, Technology and Research), Singapore. V. R. Vangala thanks Royal Society of Chemistry for Researcher Mobility Grant (2015/17).

Chez de nombreuses Angiospermes, la pollinisation croisée est nécessaire pour le succès de la reproduction. La plupart de ces plantes ont évolué afin de favoriser la pollinisation entomophile, principalement assurée par les abeilles. C’est le cas des Cucurbitacées, dont le melon (Cucumis melo L.), importante culture du sud de la France et le concombre d’âne (Ecballium elaterium (L.) A. Rich.) plante spontanée endémique du bassin méditerranéen, les deux modèles de cette étude. Afin de mieux comprendre les relations plante-pollinisateur,nous avons choisi de caractériser le couple pollen de Cucurbitacées/abeille domestique (Apis mellifera L.) à travers la production de pollen, sa présentation sur la fleur et son transport sur l’abeille. Nous avons montré que, chez ces plantes, l’ontogenèse du pollen s’accompagne d’erreurs développementales conduisant à la formation de près de 3% de grains de pollen vides. De plus, nous avons mis en évidence que chez E. elaterium, des erreurs méiotiques entraînaient la formation de grains de pollen génétiquement anormaux qui pourraient être source d’autopolyploïdie. Chez C. melo, nos résultats ont révélé que la mise en contact du pollen avec le milieu environnant entraîne une baisse de 30% de sa viabilité, mais que celle-ci reste stable jusqu’à la fin de l’anthèse. L’aptitude à germer, quant à elle, finit d’être acquise juste avant anthèse et décroît de 12% en fin de période d’anthèse. Nous avons montré que le pollen de C. melo transporté sur le corps de l’abeille pouvait soit avoir une viabilité et une aptitude à germer préservée, probablement par protection contre la déshydratation, soit perdre quasi-totalement sa viabilité et son aptitude à germer. Enfin, nous avons détecté des composés biochimiques spécifiques des abeilles protégeant ou diminuant la qualité reproductrice du pollen / For many flowering plant species cross pollination is necessary to ensure reproductive success. Most of these plants have evolved to encourage insect pollination which is mainly carried out by bees. Such is the case of plants in the Cucurbitaceae family, including the cantaloupe (Cucumis melo L.), an important crop of the South of France, and squirting cucumber (Ecballium elaterium (L.) A. Rich.), a wild plant restricted to the Mediterranean Basin, the two vegetal models used in this study. To better understand plant-pollinator relations, we proposed to characterise the interaction between Cucurbitaceae pollen and the honey bee (Apis mellifera L.) through pollen production, its presentation and its transport on the honey bee body. Our results showed that developmental anomalies took place during pollen ontogenesis in these species leading to 3% of the pollen grains produced to be empty. Moreover, we demonstrated that meiotic abnormalities in E. elaterium leading to the production of genetically abnormal pollen grains could be a source of autopolyploidy. At anthesis in C. melo, our results showed that pollen viability decreased to 30% when pollen was exposed to environmental conditions, then remained stable during the period of anthesis.The ability for pollen to germinate was completed just before anthesis then decreased to 12% at the end of anthesis. We determined that viability and germinability of cantaloupe pollen carried on the honey bee body can be enhanced or decreased according to which specific honey bee biochemical compounds were detected