The waggle dance of the honey bee (Apis mellifera L.) is perhaps the most celebrated animal communication behavior. With a waggle dance, a forager bee who has discovered a profitable resource on the landscape, usually floral nectar or pollen, can inform her nestmates of its location and recruit them to exploit it by communicating both a distance and a direction. Since Karl von Frisch described the waggle dance in 1942, scientific exploration of the dance has exploded into the realms of its structure, function, role in the regulation of collective foraging in the context of the hive as a super-organism, and even its utility as a study system for understanding sublethal behavioral effects of pesticide exposure. This dissertation presents three novel studies of the waggle dance. In the first, we asked whether consistent inter-bee differences (i.e., individuality) in a waggle dance distance - duration calibrations could affect communication success. In the second, we characterized the networks of recruitment arising from waggle dance communications and explored the role of the aforementioned individuality in network formation. In the third, we tested whether sublethal exposure to glyphosate (GLY), the most-applied herbicide in the world, could affect foraging, recruitment, or the levels and balance of biogenic amines in the bee brain. In each of these experiments, we housed bees in clear-walled observation colonies and trained cohorts of bees to visit artificial feeders to record both foraging and recruitment data. In our first experiment, we found that individuality in waggle dance behavior does shape communication outcomes, indicating that individual-level behavioral differences should not be discounted as factors at work in eusocial insect societies. In the second, we present the first network density and dance burstiness data from in vivo bee networks, revealing that recruitment networks are sparse, and waggle dancers are partitioned into bursty and non-bursty behavioral types. In the third, we show that not only can sublethal GLY exposure reduce foraging, but it can also produce significant correlations between levels of the important insect neurotransmitter octopamine and its two biosynthetic precursors, tyramine and tyrosine, where levels in control bees were unrelated. The results of this dissertation research, while distinct by experiment, together emphasize the continuing usefulness and tractability of the honey bee colony as a system in which to study the role of individuality in animal communication and to better understand the threat posed by non-insecticidal pesticide chemistries to the planet's most economically impactful pollinator. / Doctor of Philosophy / One of the most famous and well-studied animal behaviors is the waggle dance of the honey bee. A honey bee's waggle dance works similarly to a Yelp review for a restaurant: a bee who has found a good food source, like a flower patch offering especially sweet nectar or high-quality pollen, can come back to the colony and recommend it to her nestmates with a dance. The waggle dance is even more specific than a Yelp review, however, in that it also gives instructions to find the food source, communicating both a distance and a direction so that dance followers can go out into the landscape and look for the food source themselves. Even though the waggle dance has been studied extensively since it was first described by Karl von Frisch in the 1940s, there are still unknowns about how it works, and how it might be impacted by certain stressors. This dissertation presents three different experiments aimed at shedding light on these unknowns. First, it has recently been shown that there are consistent differences between bees in the way they communicate distance in the dance, and we tested whether that between-bee individuality can affect the likelihood that two bees will communicate successfully. Second, we studied how information about a food source moves from bee to bee via the waggle dance to form a communication network. Specifically, we described how efficiently information moved from bee to bee, patterns of dancing behavior, and the role of that individuality in its formation. Third and lastly, we looked to see whether exposure to a weedkiller called glyphosate (GLY) could affect either honey bees' waggle dance or food-collecting behavior, as well as levels of certain neurotransmitters in their brains that are involved in those behaviors. In all three experiments, we collected our data by housing bees in a clear-walled observation hives that let us view and film their waggle dance behavior, and then training groups of bees to collect artificial nectar from a feeder station that we provided, so we could also observe them as they collected food. We found that individuality in waggle dance communication can indeed affect the likelihood of communication success between two given bees, where the likelihood of communication success is greater when the dancer communicates a farther distance to the food source than the follower would. In the second experiment, our study of the waggle dance communication network showed that (1) information does not flow from bee to bee very efficiently, and (2) bees either dance quite regularly or sporadically. As far as we know, we are the first to describe these aspects of the waggle dance communication network, which may be useful in the field of computing algorithms inspired by living organisms. Finally, our third experiment showed that mild GLY exposure not only reduced how frequently bees collected food from our feeder, but also changed the relative amounts of certain neurotransmitters in their brains. This result emphasizes the importance of understanding how weedkillers that are not meant to target beneficial insects like honey bees are actually affecting them, so that we can make better-informed decisions to protect honey bees and other good insects.

Abstrakt.Syftet med denna studie är att ta reda på vad som kan göras i trädgårds- och balkongmiljöer för solitära bins överlevnad, då arter redan gått förlorade eller är rödlistade på grund av dåliga förutsättningar i fråga om habitat. Hur kan utformningen av designförslag se ut för trädgård och balkong? Vad innehåller lämpliga habitat samt hur ser hotbilden ut för solitära bin? Målet med denna litteraturstudie var att finna svar på mina frågeställningar. Utifrån de fakta som framkommit från resultaten har sedan designförslag utformats för trädgårds- och balkongmiljöer. Ökad biotopyta från forna tiders mosaiklandskap kan i ny tappning utformas som trädgårds- och balkongmiljöer i form av giftfria och blomrika små ängar, blommande kantzoner, diken och rabatter, krukväxter, blommande träd och buskar. Solitära bin behöver husrum, vatten att dricka och mat att äta i form av nektar- och pollenrika växter. De behöver blommande växter från tidig vår till sen höst för att överleva. Viktigt att sprida kunskap och förståelse för hur solitära bin lever sina liv så att människor kan samarbeta för att nå långsiktiga hållbara habitatlösningar. Solitära bin behöver många blommande växtytor som kan fungera som spridningskorridorer in i de urbana miljöerna där varenda liten kvadratmeter blommande yta har betydelse. Solitära bin ökar i antal med ökad biotopyta är fakta som designförslagen baserats på. Förödande hot för solitära bin är bland annat blombrist i urbana miljöer, besprutning med olika gifter, tambin som sprider sjukdomar, människans rädsla för små kryp samt förändrade livsmiljöer. / Abstract. The purpose of this study is to find out what can be done in gardens and balconies for solitary bees survival, species have already been lost or are red-listed because of poor conditions in terms of habitat. What can design-proposals look like for gardens and balconies? What do suitable habitats contain and what do threats look like for solitary bees?The goal with this literature study was to find answers to my questions. Based on facts that emerged from the results, design proposals have been made for gardens and balconies. Increased biotope-surface from ancient times mosaic-landscape can in modern environments like gardens and balconies be designed as non-toxic and flower-rich meadows, flowering border zones, ditches and flower beds, potted plants, flowering trees and shrubs. Solitary bees need shelter, water to drink and food to eat as in nectar and pollen-rich plants. They need flowering plants from early spring to late autumn to survive. It´s important to spread knowledge and understanding how solitary bees live their lives, that people can cooperate to achieve long-term sustainable habitat solutions. Solitary bees need many flowering plant-surfaces that can act as dispersal corridors in to urban environments, where every single square meter flowering-surface is of importance. Solitary bees increase in number with increasing biotope-surfaces which are facts that design proposals are based on. Devastating threats for solitary bees are floral shortage in urban areas, spraying with various poisons, domestic bees spreading diseases, human fear of small insects and altered habitats.

Body size is a universal property affecting biological structure and function, from cell metabolism to animal behavior. The nervous system, the physical generator of behavior, is also affected by variations in body size; hence potentially affecting the way animals perceive, interpret and react to the environment. When animals join to form groups, such individual differences become part of the structure of the society, even determining social roles. Here, I explore the association between body size, behavior and social organization in honeybees and bumblebees. Focusing on bumblebees, I explore the link between body size, brain allometry and learning and memory performance, within the context of task specialization. I show that body size goes along with brain size and with learning and memory performance, and that foraging experience affects such cognitive and neural features. Next, I explore the association between body size and foraging task specialization in honeybees. Previous evidence showed a link between specialization on pollen or nectar foraging and sensory sensitivity, further associating sensitivity to the quality and/or quantity of resource exploited. I hypothesize that, as in solitary bees, larger body size is associated with higher sensory sensitivity. I test this hypothesis by comparing body size and the quality and quantity of the resource exploited by wild Africanized and European honeybees. I show that nectar foragers are smaller and have fewer olfactory sensilla, which might underlie their lower sensitivity to odors. Also, larger bees collect more pollen (within pollen foragers) and more dilute nectar (within nectar foragers). To further test this `size hypothesis', I compare strains of bees selected to store large ("high strain") or small ("low strain") amounts of pollen surplus. As these strains differ in sensory sensitivity, I predict that the more sensitive high strain bees are larger and have more sensory sensilla. I show that high strain bees are generally bigger, but have fewer sensory sensilla than low strain bees. These results show that in bees, body size is associated with an individual's sensory, neural and cognitive features, further suggesting that body size plays a more important role in the organization of bee societies than generally assumed.

Animals in general vary immensely in body size, which greatly affects their morphology, physiology, survival, and nutritional requirements. The nervous system is also affected by variation in body size, which, in turn, shapes the perception of environmental stimuli and the behavior of animals. Comparative studies of vertebrates suggest that larger brains and their integrative centers comprise more and generally larger neurons (Jerison, 1973; Kaas, 2000), but much less is known about brain - body size relations in invertebrates. Closely related social bee species are well suited to study correlations between body size and brain composition. Different honey bee species vary in body size yet differ little in their ecological requirements and behavior and bumble bees feature a large range of body sizes even within a single colony.

The honeybees Apis cerana and Apis mellifera are derived from the same ancestral base about two million years ago. With speciation and evolution, they have acquired many advanced living skills in common, but have also evolved very different living strategies due to different distributions. This thesis is an intensive study of the biology of the mixed-species colonies of these species, the aims of which were to investigate their behavioural relationships and uncover the evolutionary conserved features of their behaviours subsequent to speciation. The results show that the two species can form a stable society to perform normal tasks. First, workers of both species in the mixed-colonies could form the typical retinue behaviour to hetero-species queens, thus indicating that queen pheromones could be spread to and by both species. Secondly, both species did not show significantly different ovarian activation under hetero-species queens, suggesting that the queen pheromones more likely play a role of "honest signal" rather than a "repression" substance in the honeybee colonies. Thirdly, both species could mutually decode each other‘s waggle dances, with unexpectedly low misunderstanding; revealing that the dance language in a dark environment is quite adaptive for cavity-nesting honeybees. Fourthly, workers of both species could cooperate with each other in comb construction, although the combs they built contain many irregular cells. Interestingly, A. cerana workers could be stimulated by A. mellifera workers to perform this task, thus confirming self-organization theory in the colony. Fifthly, A. mellifera workers behaved more "defectively" in thermoregulation, but perhaps because A. cerana workers are more sensitive to changes in hive temperature. Given these differences in strategy, A. mellifera workers‘ performance might in fact reduce conflicts. Lastly, when faced with threats of predatory wasps, both species engaged in aggressive defence. Although they did not learn from each other‘s responses, species-specific strategies were adopted by each of them so that the defence of the mixed-colonies is very effective. I conclude that the two species can adapt to each other‘s efforts and task allocation is reasonably organized allowing mixed-species colonies to reach stability. These results suggest that all of the social behaviours discussed here were highly conserved following speciation. This thesis could provide some clues for the study of honeybee evolution from open-nesting to the transition of cavity-nesting.

Brazil is the country with the second-largest number of cataloged bee species in the world, about 2,000. Among these we have stingless bees, with around 250 different species; these live in society, produce honey, and unlike the European Apis Mellifera, do not sting. Sadly, most Brazilians only know of the existence of a single bee species, which is the invasive European bee. Native bees are not only the most important pollinators of our native flora but are also part of an intricate and fragile web of life that is currently under threat. For each bee species that go extinct, there are far-reaching consequences for the entire ecosystem it belongs to, therefore it’s imperative to protect and care for our native bees.In this project, I've worked alongside the Terra Mirim foundation. I’ve compiled information on native bees, their biology, the native history of beekeeping, societal behavior, their importance, risks, etc. I started this work in collaboration with Terra Mirim, a foundation that works on the recovery of the Atlantic Forest and has over 60 native beehives under their care, they also receive many visitors throughout the year who are looking for closer contact with nature. I believe awareness, knowledge, and proximity are important starting points for developing empathy towards other forms of life, so along with the photographs I’ve been taking, I am transforming the information I compiled into signboards to promote awareness among Terra Mirim’s visitors.

The health of pollinators, especially bees, is of the utmost importance to success of many agricultural ecosystems. Microorganisms can cause diseases in bees; such microbes are pathogenic. The ability of a pathogen to cause harm to its host (such as a bee) is termed its virulence. Studying the evolution of different levels of virulence can lead researchers to a better understanding of pathogens, and potentially predict how much harm a pathogen can cause in the future. We studied the evolution of virulence levels for a fungal disease of bees. This group of fungi is composed of 28 species, and some cause a disease in bees called chalkbrood while others do not. Using what we know about virulence evolution we wanted to see if the pathogens could infect all bees, if the pathogens varied in virulence when infecting at the same time as another pathogen, and if solitary bees had any behavioral adaptations that might increase or decrease chalkbrood infection. By using DNA sequences, the relationship between the genetic structures of each of the fungal species was studied, and we found that pathogens of solitary bees grouped together while pathogens of social bees (honey bees) were not part of this group. We then found that a solitary bee pathogen did not infect honey bees very well, and vice versa. The nuances of the relationship between two solitary bee pathogens were examined more closely to determine how the two pathogens interact in this bee. In this case, under varying conditions of infection, one pathogen always maintained a similar level of virulence and spore production, while the other pathogen varied in these measures. In addition, when doses of these fungi were fed to bee larvae at different times, more bees survived than when the doses were given at the same time, suggesting that bee immune responses are very important. Finally, we found no evidence of any specific behaviors of solitary bees exposed to infective spores that would suggest these bees have behaviors that are evolved to alter chalkbrood levels in populations.

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Repeated cold exposures and warmer winter temperatures might negatively affect insects by depleting stored fuel reserves. I researched the effects of fluctuating thermal regimes on two species of solitary mason bees (Osmia albiventris and O. lignaria) by quantifying mass loss and reserves of lipids, free sugars, and glycogen after experimental temperature treatments during early spring. In a second season, I quantified mass loss, time to emergence, and time to recover from chill coma after bees had been exposed to one of two spring-time temperature regimes. I found that warmer temperatures in combination with greater temperature variability increases mass loss and the depletion of fuel reserves. Additionally, my results suggest that accelerated bee emergence helps to mitigate mass loss. Overall, these bees appear resilient in the face of changing spring temperatures. Résumé: On sait peu sur la façon dont la variabilité environnementale affecte les abeilles solitaires sauvages. Ma recherche a étudié la façon dont les régimes thermiques fluctuants affectent la vigueur de deux espèces d'abeilles solitaires (Osmia albiventris et O. lignaria) en quantifiant la perte de masse ainsi que les réserves métaboliques (lipides, sucres libres, et glycogène) des abeilles suite à des manipulations expérimentales de la température printanière. Dans une deuxième saison, j’ai quantifié la perte de masse, le temps de l'émergence et le temps pour récupérer du coma froid après que les abeilles avaient été exposées à l'un de deux régimes de températures printanières. Mes résultats indiquent que les températures plus chaudes ont tendance à augmenter la perte de masse et des réserves métaboliques lorsqu'elles sont combinées avec une plus grande variabilité. De plus, mes résultats suggèrent que ces abeilles sont résilientes face aux températures printanières changeantes.

Processes structuring bee communities in agricultural landscapes are well-documented compared to those in other anthropogenic landscapes, like production forests. Forests across the temperate zone have historically been under-sampled, in part due to the perception that they provide little habitat to support diverse bee communities. While research suggests that early successional habitats support high levels of bee species richness and abundance, little empirical evidence exists to support the notion that forests, in turn, do not. To understand the relationship between forest successional age and major elements of the bee community, I sampled bees in a southern production pine forest in Hancock County, MS across 2012 and 2013. I found that while bee abundance declines with successional age, species richness does not. Combining this work with other recent research, I propose a generalized framework for understanding the role of disturbance and forest structure in structuring bee communities of southern forests.