MORPHOMETRIC AND GENETIC DIFFERENTIATION BETWEEN ANATOLIA AND CYPRUS BOMBUS (BOMBUS) TERRESTRIS (L. 1758) POPULATIONS BETON, Damla M. Sc., Department of Biology Supervisor: Prof. Dr. Aykut Kence September 2004, 86 pages Four microsatellite loci were used to investigate differentiation in Bombus terrestris, a bumblebee of interest for its high value crops pollination. Two bumblebee populations, one from Ankara (the capital of Turkey) and one from North Cyprus were analyzed. In these populations, the total number of alleles detected per polymorphic locus ranged from 7 to 12. FST genetic distance between Ankara and North Cyprus B. terrestris populations based on four microsatellite loci was calculated as 0,09351. This applies that there is significant (P&lt / 0,001) differentiation between Anatolian and Cypriot populations. Moreover, statistically significant differences between two populations were found in wing characters studied. According to the potential for local adaptation and individual fitness of bumblebees, microsatellite data calls for protection of Bombus terrestris populations against importation of bumblebees of foreign origin which are used as crop pollinator.

The Swedish forest has been transformed during the last hundred years, from semi-open forest of multiple tree species to dense production forest of mainly spruce and pine. This has led to alterations of species composition in the forest floor, reducing coverage of dwarf shrubs like Vaccinium myrtillus (European blueberry). Bumblebees (Apidae: Bombus spp.) forage from V. myrtillus flowers and it forms together with other early flowering plant species a foundation for bumblebee colony establishment in spring. Against this background I examined how resources of V. myrtillus in the landscape affect bumblebees. I also studied the influence of season on preferred bumblebee forage habitat, comparing forests with road verges in the open landscape. The research was conducted in spring and summer of 2021 in the county of Södermanland in Sweden. Bumblebees were sampled in forests and road verges in 20 study landscapes, dominated by a forest-farmland mosaic. Bumblebee abundance and species richness was found to increase with coverage of V. myrtillus shrubs in forests during flowering of V. myrtillus in spring and with coverage of flowers in forests and road verges in summer. Bumblebees were also found to mainly forage in forests in spring and in road verges in summer and approximately the same bumblebee species occurred in both habitats. I conclude that bumblebees moves in between the forest and the open landscape in seasons, controlled by availability of flowers in the habitats. It is further concluded that V. myrtillus flowers is an important forage resource for bumblebees in spring. This calls for a landscape perspective managing bumblebees in forest-farmland landscapes in Sweden, recognizing the importance of forest forage resources as well as forage resources in the open landscape. A forest management that acknowledge the need for forest floor conditions supporting dwarf shrubs like V. myrtillus and summer flowering species is further recommended in order to preserve bumblebees in Swedish forest-farmland landscape.

Biodiversity is declining across the globe, and human-driven climate change and land-use change are among the primary drivers of this loss. Understanding the mechanisms causing declines is critical for developing effective conservation and management strategies which will not only slow biodiversity loss, but reverse it. This is relevant for virtually all species on the planet, but given the ecosystem services that they provide, pollinators are an especially important group in which to study this. Among the wild pollinators native to North America and Europe, bumblebees (Bombus) are a particularly important and beautiful group. In this thesis, I identify how climate change and land-use change interact to influence population and community change in North American and European bumblebees, and I explore the potential role of protected areas in mitigating declines. I find that climate change has increased local extinction risk for bumblebees by exposing them to temperatures beyond their historic tolerances, and I introduce a broadly applicable method which improves prediction of this climate change-related risk (Chapter 2). Examining the interactions between climate change and land-use change shows that the risk from increasing temperatures and temperature extremes is worse in historically degraded areas, and that climate change and land-use change may be driving biotic homogenization in bumblebee communities. Yet, landscape-scale patterns suggest that human land-use can be managed to have minimal, or even positive, effects on pollinators (Chapter 3). In the face of these global pressures, protected areas represent one way to conserve species. I find that increasing the amount of protected area in a region, regardless of size or management category of the protected areas, is related to reduced local extinction risk for bumblebees across North America and Europe. This benefit is especially strong in areas with high human land-use, highlighting the importance of protected areas in highly human-dominated landscapes (Chapter 4). The work within my thesis improves our understanding of how climate change and land-use change drive shifts in species and communities, and can inform on the effectiveness of specific conservation actions from gardens and urban greenspaces, to Other Effective Area-Based Conservation Measures (Chapter 5).

I dagsläget importeras omkring 4600 humlebon årligen från Europa till Sverige för att öka produktionen av grönsaker och då framförallt tomater. Sverige har i dagsläget ingen egen produktion av humlor men bolaget Svenska Humlor AB ämnar att starta en försäljning under 2021. Att humlorna är svenskuppfödda och närda på svensk pollen är en ny produkt på marknaden som kan medföra nya intressen och intressekonflikter från olika aktörsperspektiv. Syftet med denna studie är att skapa en ögonblicksbild av åsikter som finns kring att starta en inhemsk försäljning av humlor av arten Bombus terrestris. Vidare är ett mål är att utreda hur en framtida svensk humleproduktion kan utformas och hur det kan relatera till hållbar utveckling. Studien kopplar till FN:s Agenda 2030 och målet att bevara biodiversitet och ekosystem. Humlor påverkas av klimatförändringar och flyttar därför till nya områden. Vidare hotas vissa humlearter av antropogen påverkan av landskapen. Humlornas pollinering möjliggör större skördar, som i sin tur bidrar till en ökad matproduktion som också är en målsättning i Agenda 2030. Humlesamhällen föds därför upp och placeras i jordbrukarnas odlingar.  Studien berör både för- och nackdelar med en potentiell svensk produktion av humlor. Intervjuer genomfördes med fyra för ämnet viktiga aktörer; humleuppfödare, jordbrukare, myndighet och akademi. De har ombetts diskutera de största styrkorna, svagheterna, möjligheterna och hoten med att införa svenska humlor som en ny produkt. Dessa åsikter presenteras i SWOT-diagram. SWOT är en metod för att analysera en organisation eller verksamhet där argument delas in efter styrkor (S), svagheter (W) möjligheter (O) och hot (T). Intervjuerna och SWOT-analysen struktureras med fyra huvudteman: ekonomi, teknik, ekologi och övrigt. En litteraturstudie utfördes för att få fördjupade kunskaper i ämnet inför intervjuerna. Litteraturen användes också för att styrka vissa fakta som påståtts av intervjupersonerna. I studien analyseras och diskuteras de huvudämnen som lyftes av de olika aktörerna, för att skapa en bild av vad en framtida svensk humleproduktion kan innebära.  Det framkommer bland annat att det kan vara fördelaktigt att producera svenska humlor jämfört med att importera, då det minskar risken att föra in sjukdomar som kan drabba de vilda pollinerarna. De importerade humlorna från Europa är av en annan underart än de svenska vilda humlorna, varför svenskuppfödda humlor även har mindre påverkan på den vilda genetiken. Vidare lyfts att även fler insekter kan vara relevanta för kommersiell pollinering. Andra diskussionspunkter är bland annat hur ny lagstiftning kan påverka svensk humleuppfödning, möjligheter till lönsamhet, svensk självförsörjningsgrad, inavel i uppfödningen, jämförelser med norsk humleuppfödning, återanvändning av material samt samhällsopinion kring att ha humlor som ett produktionsdjur. Studien avser att samla åsikter kring temat i en uppstartsfas av svensk humleuppfödning, för att kunna användas som diskussionsunderlag och ligga till grund för framtida studier. / Sweden imports around 4600 bumblebee colonies per year from Europe to increase the production of vegetables, primarily tomatoes. Sweden currently lacks a domestic bumblebee rearer, however the company Svenska Humlor AB plans to start selling colonies by 2021. Swedish bumblebees reared on swedish pollen is a new type of product that opens a whole new market. This can cause new undocumented interests and conflicts from different actor’s perspectives. The objective of this study is to portray a current view of opinions regarding a domestic market for bumblebees of the species Bombus terrestris. Furthermore, the study aims to investigate the future of Swedish bumblebee rearing and how it relates to sustainable development. The study integrates the United Nations’ Agenda 2030 Sustainable Development Goals since it includes conservation of biodiversity and ecosystems. Bumblebees are affected by climate change and therefore migrate to new areas. In addition, anthropogenic influence of the landscapes affects their functions. A great advantage is that bumblebee pollination contributes to food production which is included in the Agenda 2030, since bumblebee pollination increases the harvest. Hence, bumblebee colonies are bred and placed in the plantations.  The study covers advantages and disadvantages regarding a potential start-up of swedish reared bumblebees. To achieve this, interviews were conducted with four different actors; a bumblebee rearer, a farmer, authority and academy. They were asked to discuss the greatest strengths, weaknesses, opportunities and threats regarding a Swedish domestic bumblebee rearing. These opinions are presented in SWOT-diagrams, which is a method used to analyse an organisation or business model where strengths (S), weaknesses (W), opportunities (O) and threats (T) are identified and discussed. The interviews and SWOT-analysis are structured around four main themes; economy, technology, ecology and other. Additional literature was also used to strengthen facts that were brought up by the interviewees. The study aims to discuss the main themes raised by the different actors in relation to literature to create a picture of a future Swedish production.  During the interviews it was discussed that Swedish bumblebees might be beneficial in comparison to imported bumblebees as they lower the risk of spreading pathogens to wild pollinators. The imported bumblebees from Europe are of a different sub-species than the indigenous bumblebees. Due to this the Swedish bred bumblebees affect the native genetics less than their imported counterparts. It was also noted that other insects could be used as pollinators in the future. Other points of discussion related to a future Swedish bumblebee rearing were: new regulations, profitability, Swedish self-sufficiency, reusable materials for nests, inbreeding and opinions regarding the usage of bumblebees in production. The study provides opinions regarding these topics which are meant to be used for discussion as well as in future work.

A abelha Bombus terrestris é um eficiente polinizador, prestando importantes serviços ecossistêmicos na Europa e adjacências, onde é nativa. Suas colônias têm sido criadas em larga escala para polinização agrícola, as quais são comercializadas internacionalmente, inclusive em países fora de sua área de ocorrência nativa. Deliberada ou acidentalmente a espécie tem sido introduzida em ambientes alóctones, em muitos casos tornando-se invasora. Quando invasora, a espécie é um potencial vetor de doenças e um competidor com outras abelhas; vários impactos têm sido relatados em áreas invadidas ao redor do mundo. Na América do Sul, a espécie foi inicialmente introduzida em ambientes naturais no Chile, mas rapidamente a invasão se espalhou; atualmente é encontrada ocupando ambientes naturais na Argentina. A elevada capacidade invasiva da espécie e a alta velocidade de sua expansão, conforme tem sido relatada por pesquisadores, levantou a possibilidade de a espécie alcançar o Brasil por meio de corredores ambientais favoráveis que se conectam com áreas já invadidas, gerando preocupações sobre potenciais impactos aos sistemas naturais e agrícolas. Esta pesquisa empregou uma abordagem interdisciplinar, integrando uma variedade de métodos analíticos oriundos de diferentes áreas da ecologia e os mais avançados recursos de sistemas de informações geográficas para detectar globalmente as áreas susceptíveis à invasão por Bombus terrestris, considerando-se também as mudanças climáticas. Para o sul da América do Sul foram identificados os corredores de invasão que poderão permitir a espécie se espalhar e alcançar Brasil a partir de locais invadidos. Para o Brasil, foram identificados os municípios mais vulneráveis à entrada da espécie, e também aqueles que estão na rota de expansão da invasão Brasil adentro. Para os municípios brasileiros, por sua vez, foram verificadas as culturas agrícolas e as espécies de Bombus nativas que a invasora poderá interagir ao longo da rota de invasão potencial; com estas informações foram apontadas áreas prioritárias, subsidiando o planejamento de monitoramento e ações de controle do processo de invasão, mas também medidas preventivas e mitigadoras de impactos ambientais e econômicos após a invasão, caso venha a ocorrer. / The bee Bombus terrestris is an efficient pollinator, providing important ecosystem services in Europe and surrounding areas, where it is a native species. Their colonies have been reared in large-scale for agricultural pollination, which are internationally traded, including for countries outside its native range. The species has been deliberately or accidentally introduced into non-native environments, becoming invasive in many cases. When invasive, the species is a potential vector of diseases and competes with other bees for resources; many impacts have been reported in invaded countries around the world. In South America, the species was introduced in natural environments of Chile at first, but the invasion was quickly spread; nowadays it is found living in natural environments of Argentina. The high invasiveness of the species and the high speed of its invasive expansion, as has been reported by researchers, raised the possibility of the species reach Brazil through suitable environmental corridors that are connected with areas already invaded, raising the concerns about potential impacts to natural and agricultural systems. An interdisciplinary approach was used in this research, composing a variety of analytical methods from different areas of ecology and applying the most advanced resources of geographic information systems to detect areas susceptible to invasion by Bombus terrestris at global scale, considering also climate change. For the southern South America, the corridors of invasion that could allow the spreading of the species and that potentially reach Brazil were identified. For Brazil, the most susceptible municipalities at the entrance of the species have been identified, and also those that are on the route of expansion inside the country. For Brazilian municipalities, crops and native species of Bombus that the invasive species can interact with along the potential invasion route were verified; with this information, priority areas were identified, supporting the planning of monitoring and control actions of the invasion process, but also preventive and mitigating measures of environmental and economic impacts after the invasion, if it eventually occurs.

A abelha Bombus terrestris é um eficiente polinizador, prestando importantes serviços ecossistêmicos na Europa e adjacências, onde é nativa. Suas colônias têm sido criadas em larga escala para polinização agrícola, as quais são comercializadas internacionalmente, inclusive em países fora de sua área de ocorrência nativa. Deliberada ou acidentalmente a espécie tem sido introduzida em ambientes alóctones, em muitos casos tornando-se invasora. Quando invasora, a espécie é um potencial vetor de doenças e um competidor com outras abelhas; vários impactos têm sido relatados em áreas invadidas ao redor do mundo. Na América do Sul, a espécie foi inicialmente introduzida em ambientes naturais no Chile, mas rapidamente a invasão se espalhou; atualmente é encontrada ocupando ambientes naturais na Argentina. A elevada capacidade invasiva da espécie e a alta velocidade de sua expansão, conforme tem sido relatada por pesquisadores, levantou a possibilidade de a espécie alcançar o Brasil por meio de corredores ambientais favoráveis que se conectam com áreas já invadidas, gerando preocupações sobre potenciais impactos aos sistemas naturais e agrícolas. Esta pesquisa empregou uma abordagem interdisciplinar, integrando uma variedade de métodos analíticos oriundos de diferentes áreas da ecologia e os mais avançados recursos de sistemas de informações geográficas para detectar globalmente as áreas susceptíveis à invasão por Bombus terrestris, considerando-se também as mudanças climáticas. Para o sul da América do Sul foram identificados os corredores de invasão que poderão permitir a espécie se espalhar e alcançar Brasil a partir de locais invadidos. Para o Brasil, foram identificados os municípios mais vulneráveis à entrada da espécie, e também aqueles que estão na rota de expansão da invasão Brasil adentro. Para os municípios brasileiros, por sua vez, foram verificadas as culturas agrícolas e as espécies de Bombus nativas que a invasora poderá interagir ao longo da rota de invasão potencial; com estas informações foram apontadas áreas prioritárias, subsidiando o planejamento de monitoramento e ações de controle do processo de invasão, mas também medidas preventivas e mitigadoras de impactos ambientais e econômicos após a invasão, caso venha a ocorrer. / The bee Bombus terrestris is an efficient pollinator, providing important ecosystem services in Europe and surrounding areas, where it is a native species. Their colonies have been reared in large-scale for agricultural pollination, which are internationally traded, including for countries outside its native range. The species has been deliberately or accidentally introduced into non-native environments, becoming invasive in many cases. When invasive, the species is a potential vector of diseases and competes with other bees for resources; many impacts have been reported in invaded countries around the world. In South America, the species was introduced in natural environments of Chile at first, but the invasion was quickly spread; nowadays it is found living in natural environments of Argentina. The high invasiveness of the species and the high speed of its invasive expansion, as has been reported by researchers, raised the possibility of the species reach Brazil through suitable environmental corridors that are connected with areas already invaded, raising the concerns about potential impacts to natural and agricultural systems. An interdisciplinary approach was used in this research, composing a variety of analytical methods from different areas of ecology and applying the most advanced resources of geographic information systems to detect areas susceptible to invasion by Bombus terrestris at global scale, considering also climate change. For the southern South America, the corridors of invasion that could allow the spreading of the species and that potentially reach Brazil were identified. For Brazil, the most susceptible municipalities at the entrance of the species have been identified, and also those that are on the route of expansion inside the country. For Brazilian municipalities, crops and native species of Bombus that the invasive species can interact with along the potential invasion route were verified; with this information, priority areas were identified, supporting the planning of monitoring and control actions of the invasion process, but also preventive and mitigating measures of environmental and economic impacts after the invasion, if it eventually occurs.

The spreading of the invasive plant Garden Lupine (Lupinus polyphyllus) has become a matter of national importance in Sweden, due to it posing a threat to native plant and pollinator diversity. The effective attraction of bumblebees (Bombus spp.) as pollinators facilitates the production of large numbers of seeds, which are key to the Garden Lupine’s success. Possible self-pollination could also provide a competitive edge for the plant. The objective of this study was to study the relationships between Garden Lupine color morphs, pollinator attraction and seeding. Inflorescences of three color morphs were studied during the flowering period, and bumblebee behavior was observed on the site. After seeding, any produced seeds were collected and analyzed, as well as experimentally germinated to provide insight into their viability. A subset of inflorescences of each color morph was prevented access to pollinators, to study potential self-pollination effects. Bumblebees preferred blue flowers over pink, but no difference in pollination between the color morphs was found. Flower color did not affect seed production or seed morphology. Self-pollinated inflorescences produced fewer seeds than those with access to pollinators, but no difference in seed morphology or germinative success between the pollination methods could be established. The results suggest that seed production and germination are less dependent on pollination than expected. The ability to germinate through self-pollination provides insight into the invasive potential of Garden Lupine, suggesting that further studies are needed to successfully counteract its spread. / Den invasiva växten blomsterlupin (Lupinus polyphyllus) har på senare år blivit en nationell angelägenhet i Sverige, där den hotar mångfalden av inhemska växter och pollinatörer. Blomsterlupinens framgångsrika tilldragning av framförallt humlor (Bombus spp.) som pollinatörer möjliggör det stora antalet frön som den producerar, vilket är nyckeln till dess invasiva etablering. Eventuell förmåga till självpollinering kan också utgöra en konkurrensfördel. Målet med studien var att utforska relationen mellan blomsterlupinens färgmorfer, pollinering samt fröbildning. Blomställningar av tre färgmorfer studerades under blomningsperioden. Humlornas beteende observerades också under perioden vid lupinlokalen. Efter frösättning samlades alla producerade frön upp och analyserades, varefter ett frögroningsexperiment utfördes för att belysa frönas grobarhet. I ett fältexperiment nekades en delmängd av blomställningarna tillgång till pollinatörer, för att studera eventuell självpollinering och dess effekter. Humlorna föredrog blåa blommor före rosa, men ingen skillnad i pollinering mellan färgmorferna kunde fastställas. Blommornas färg hade ingen effekt på fröproduktion eller -morfologi. Självpollinerade blomställningar producerade färre frön överlag än de med tillgång till pollinatörer, men ingen skillnad i frömorfologi eller grobarhet mellan pollineringsmetoderna kunde påvisas. Resultaten antyder att fröproduktion och frögroning hos blomsterlupin är beroende av pollinering i mindre grad än förväntat. Förmågan att gro genom självpollinering belyser blomsterlupinens invasiva potential, och antyder att fler studier behövs för att framgångsrikt motverka dess spridning.

Gut microbial communities exist in the vast majority of animals, and often form complex symbioses with their hosts that affect their host's biology in numerous ways. To date, the majority of studies of these complex interactions have focused on the nutritional benefits provided by the microbiota; however, the natural microbiota can also influence development, immunity, and the metabolism of its host. Apis mellifera, the honey bee, harbors a distinctive bacterial community that is present in individuals from distant locations around the world; however, the basis of the bee-microbiota association is unknown. This dissertation explores properties of the bacterial microbiota within bees, including its persistence of this association, mechanisms of transmission, localization through host ontogeny, and basic metabolic capabilities that define and maintain the symbiotic relationship. Apis and Bombus species (honey and bumble bees) share a distinct bacterial microbiota that is not present in other bees and wasps. Close analysis of the A. mellifera microbiota revealed consistent communities in adult worker gut organs and a general lack of bacteria in larvae. Contact between workers and with hive materials were identified as major routes of transmission for bacterial communities, showing the importance of social behavior in this association. Genomic analysis of a gut bacterium co-sequenced with the Bombus impatiens genome revealed it as a divergent lineage of Gammaproteobacteria, and deletions of conserved metabolic pathways, reduction in genome size, and its low GC content all suggest that the bacterial species has had a long association with its host.

In this thesis, I combined field observations and lab experiments to explore the ecological significance of floral signals in a North American wildflower, Penstemon digitalis. More specifically, to determine the potential mechanisms driving selection on floral scent, I studied how scent mediates interactions with pollinators and antagonists by (1) observing spatiotemporal variation in scent emission (2), floral volatile ability to suppress microbes (3) the honest advertisement of nectar, and (4) if scent could aid pollinator learning by reinforcing visual signals. Scent sampling of flower development, flower tissues, rewards and inflorescence day/night emission, revealed a complexity in floral scent composition and emission that could reflect several ecological functions. The floral bouquet of P. digitalis was strongest when flowers opened, primarily emitted from flower nectaries and was strongest during the day when pollinators are most active, suggesting a role in plant-pollinator interactions. Because linalool was one of the few floral compounds found in nectar where microbe growth can degrade the pollinator reward, I studied its role in plant-microbe interactions. Bacteria strains isolated from floral and vegetative tissues were exposed to varying concentrations of nectar volatiles: linalool and methyl nicotinate. Linalool inhibited bacteria growth rate from all tissue origins whereas methyl nicotinate had little effect, suggesting that microbes could drive selection on linalool emission strength.    To determine the extent that linalool could honestly signal nectar availability, linalool-nectar associations were measured for inflorescences and flowers. Linalool predicted inflorescence nectar availability but not flower, exposing a limit to its honesty. Pollinator Bombus impatiens could use linalool as a foraging signal at varying concentrations, suggesting linalool could be learned and used to choose the most rewarding plants.    Measurement and comparison of signal-reward associations for both olfactory and visual signals/cues of P. digitalis displays found display size and linalool honest indicators of nectar. Lab behaviour experiments showed multiple signals correlated with reward could increase bumblebee foraging efficiency and promote learning, providing an explanation for why floral displays are complex and consist of multiple signals.    Together my results show that an integrated approach is required to understand the mechanisms driving the evolution of the floral phenotype.

Bumblebees are important pollinators that are said to be in decline all over the world. Swedish bumblebees have now been inventoried through a nationwide monitoring program for which data for the first time have been analysed. The aim here was to give an indication of how 35 bumblebee species in Sweden have changed in occurrence over five years interval in the national inventory program. The results given in this report showed that 5 bumblebee species (B. lucorum, B. magnus, B. cryptarum, B. terrestris and B. pascuorum) had declined significantly. Furthermore bumblebees as a group had a significant decline while none of the species had increased. Moreover, declining Swedish bumblebees are species that are common in Europe while species that are declining in Europe do not seem to decline in Sweden. This result was somewhat unexpected, considering the European status of bumblebee species. Furthermore results showed that early emerging species and species living in ubiquitous and open areas had declined. This was also surprising comparing with previous research. Lastly the results showed that two bumblebee species (B. hortorum and B. terrestris) have shifted towards the south within Sweden while none shifted towards north or in a west-east direction.