Local Bee Research Articles

Identifying and modeling the impact of neonicotinoid exposure on honey bee colony profit

Abstract Pollination by the European honey bee, Apis mellifera, is essential for the production of many crops, including highbush blueberries (Vaccinum corymbosum). To understand the impact of agrochemicals (specifically, neonicotinoids, a class of synthetic, neurotoxic insecticides) on these pollinators, we conducted a field study during the blueberry blooms of 2020 and 2021 in British Columbia (B.C.). Forty experimental honey bee colonies were placed in the Fraser Valley: half of the colonies were located within 1.5 km of highbush blueberry fields (“near” colonies) and half were located more than 1.5 km away (“far” colonies). We calculated risk quotients for these compounds using their chronic lethal dietary dose (LDD50) and median lethal concentration (LC50). Pesticide risk was similar between colonies located near and far from blueberry forage, suggesting that toxicity risks are regionally ubiquitous. Two systemic neonicotinoid insecticides, clothianidin and thiamethoxam, were found at quantities that exceeded chronic international levels of concern. We developed a profit model for a pollinating beekeeper in B.C. that was parameterized by: detected pesticide levels; lethal and sublethal bee health; and economic data. For colonies exposed to neonicotinoid pesticides in and out of the blueberry forage radii, there were economic consequences from colony mortality and sublethal effects such as a loss of honey production and compromised colony health. Further, replacing dead colonies with local bees was more profitable than replacing them with imported packages, illustrating that beekeeping management selection of local options can have a positive effect on overall profit.

Honey bee populations surviving Varroa destructor parasitism in Latin America and their mechanisms of resistance

The honey bee (Apis mellifera) parasitic mite, Varroa destructor, is considered one of the main causes of colony losses in European honey bee (EHB) populations around the world. However, some EHB and Africanized honey bee (AHB) populations (derived from the African subspecies A. m. scutellata) that inhabit tropical and subtropical regions of the Americas, have survived varroa mite infestations in the absence of acaricide treatments. It is conceivable to expect that these honey bee populations, which have been subjected to natural selection over decades, would have developed resistance against V. destructor or possess pre-existing adaptations that allow them to survive mite parasitism. Here, we present a comprehensive literature review describing the spread of V. destructor and the honey bee populations occurring in Latin America (LA), and summarize the evidence of resistance of those populations to V. destructor. We also analyze reports describing the potential mechanisms of mite resistance and how they operate in those honey bee populations. Studies of a few EHB, as well as of numerous AHB populations exhibiting resistance to V. destructor in LA, unveil the existence of evolutionary adaptations that restrain V. destructor population growth and provide insight into the current host-parasite relationship. This review supports the notion that selective breeding of local honey bee populations from LA could be a viable strategy to manage varroa mite infestations in colonies.

Rearing of Native Bumblebee Species Bombus haemorrhoidalis for Greenhouse Pollination in Pakistan

Greenhouse tomato production is a growing business worldwide, and it is strongly promoted by bumblebee pollination. Although there are over 250 bumblebee species worldwide, very few species have been reared successfully for greenhouse tomato pollination. Those successfully managed species, especially Bombus terrestris, are shipped around the world for commercial use. However, managed bumblebees are known to escape greenhouse facilities, have established local populations, spread disease to local bumblebees, and are blamed for the declines of some indigenous bee species. An alternative to shipping exotic bumblebees around the world is to develop local species for greenhouse pollination. Such an approach has the dual benefits of creating a new industry of insect rearing while reducing threats to local bee communities. In this study, we successfully reared Bombus haemorrhoidalis, which is the most common bumblebee species in Northern Pakistan, in a laboratory and compared its effectiveness as a tomato pollinator with that of commercial B. terrestris in a greenhouse. We found that the effectiveness of B. haemorrhoidalis in tomato pollination in a greenhouse is very similar to that of B. terrestris when it comes to the fruit size, number of seeds, and fruit weight. Our study provides an example of how to rear a native bumblebee species to pollinate local crops, which is a method that could potentially substitute the importation of non-ingenious bumblebees.

Twelve tips for starting and organizing a local Brain Bee anywhere.

The Brain Bee serves as an international platform providing high school students with opportunities for undergraduate and graduate-level education in neuroscience. This annual competition welcomes participation from high school students and schools, fostering both individual- and team-based competition in a dynamic and engaging manner. The assessment involves a primary multiple-choice and short-answer exam, a secondary neuroanatomical lab practical exam, and a final oral exam administered by affiliated faculty or coordinators. During the final oral exam, the top ten students are given three chances and simultaneously respond to the same question. They write their answers on individual whiteboards until only one student remains. This unique format not only adds an element of excitement, but also allows students to build confidence within themselves and connections within STEM fields. The importance of local Brain Bees is emphasized as winners from these chapters earn the opportunity to compete nationally, and potentially internationally. Throughout the academic year, local Brain Bees, led by college students and faculty, educate high school students about various neuroscientific fields and their STEM applications through interactive and engaging sessions. These sessions culminate in an annual competition where students explore the intricacies of the human brain, spanning human physiology, pathology, and behavior. The program also exposes students to anatomical models, research, and guest speakers within the field of neuroscience. To ensure the success and continuity of local chapters, our 12-tips article provides valuable advice for running a safe and smoothly operating Brain Bee program, promoting sustained participation and enthusiasm.

Bee-diverse habitats positively affect seed set in wild plant species

IntroductionInteractions between flowering plants and visiting wild bees are crucial for ensuring pollination and subsequent plant reproductive success. However, bee diversity in an area has rarely been recorded in relation to seed set in native plants. In this project, we investigated the effect of local wild bee communities on seed set in four common wild plant species.MethodsPotted plants of Centaurea jacea, Cichorium intybus, Sinapis arvensis, and Salvia pratensis were placed for pollination experiments, in two distinct habitat types that we expected to show distinct bee communities, namely near-natural grassland and perennial wild flower strips, in Germany.ResultsOur results showed that near-natural grassland had a higher bee species richness and an increased seed set compared with flower strips that displayed a higher bee abundance in most study locations. Although we found effects of bee diversity on seed set, we did not detect a significant effect of bee abundance. Furthermore, the seed set in response to wild bee diversity differed across the plant species.DiscussionWe conclude that bee-friendly habitats ensure a high seed set in wild plants, but that the impact varies between different plant species.

Biochemical characterization of Euphorbia resinifera floral cyathia

Euphorbia resinifera O. Berg is a plant endemic to the Northern and Central regions of Morocco known since the ancient Roman and Greek times for secreting a poisonous latex containing resiniferatoxin. However, E. resinifera pseudo-inflorescences called cyathia are devoid of laticifers and, therefore, do not secrete latex. Instead, they exudate nectar that local honey bees collect and craft into honey. Honey and cyathium water extracts find a broad range of applications in the traditional medicine of Northern Africa as ointments and water decoctions. Moreover, E. resinifera monofloral honey has received the Protected Geographic Indication certification for its outstanding qualities. Given the relevance of E. resinifera cyathia for bee nutrition, honey production, and the health benefit of cyathium-derived products, this study aimed to screen metabolites synthesized and accumulated in its pseudo-inflorescences. Our analyses revealed that E. resinifera cyathia accumulate primary metabolites in considerable abundance, including hexoses, amino acids and vitamins that honey bees may collect from nectar and craft into honey. Cyathia also synthesize volatile organic compounds of the class of benzenoids and terpenes, which are emitted by flowers pollinated by honey bees and bumblebees. Many specialized metabolites, including carotenoids, flavonoids, and polyamines, were also detected, which, while protecting the reproductive organs against abiotic stresses, also confer antioxidant properties to water decoctions. In conclusion, our analyses revealed that E. resinifera cyathia are a great source of antioxidant molecules and a good food source for the local foraging honeybees, revealing the central role of the flowers from this species in mediating interactions with local pollinators and the conferral of medicinal properties to plant extracts.

Thermal parameter inversion of low-heat cement concrete for Baihetan arch dam

For the first time, low-heat cement was used in the entire dam section of Baihetan Dam, but the thermal properties of low-heat cement under construction conditions have yet to be fully studied. The thermal parameter values of low-heat cement may differ significantly from the indoor test values or specification values due to factors such as ambient temperature, cooling through water, and surface insulation under actual site conditions. Therefore, in order to obtain more accurate values of the thermal parameters, the hybrid swarm intelligence algorithm and field temperature monitoring data are used to identify the concrete thermal parameters of Baihetan arch dam. To overcome the shortcomings of Particle Swarm Optimization (PSO) that is easy to fall into local optimum and Artificial Bee Colony (ABC) that has insufficient development ability, an Integrated Algorithm Based on ABC and PSO (IABAP) is established. Through eight different test functions and comparing with other different algorithms, it is verified that the IABAP algorithm has certain advantages in terms of convergence speed and accuracy. Considering the influence of ambient air temperature and multi-shift water cooling during construction, IABAP is applied to the inversion of concrete thermal parameters with the same strength, different strength and different gradation of Baihetan arch dam. The computational results show the good performance of the IABAP algorithm in engineering applications on the one hand, and the applicability and reliability of the parameter inversion on the other hand, which can meet the accuracy requirements of practical engineering. At the same time, the conjecture that the thermal parameters are consistent in adjacent dam sections was verified by bringing the thermal parameters into the adjacent dam sections for simulation calculations. Finally, the experimental values of thermal parameters of low-heat cement concrete of Baihetan Dam were compared with the inverse values to analyze the change law of thermal parameters, and it was found that the final adiabatic temperature rise of low-heat concrete was smaller than the indoor experimental values during the actual construction.

Estimates of the vitality and performances of Apis mellifera mellifera and hybrid honey bee colonies in Siberia: a 13-year study.

Honeybees display a great range of biological, behavioral, and economic traits, depending on their genetic origin and environmental factors. The high diversity of honeybees is the result of natural selection of specific phenotypes adapted to the local environment. Of particular interest is adaptation of local and non-local bee colonies to environmental conditions. To study the importance of genotype-environment interactions on the viability and productivity of local and non-local bee colonies, we analyzed the long-term dynamics of the main traits in dark forest bees (Apis mellifera mellifera) and hybrid colonies. From 2010 to 2022, a total of 64 colonies living in an apiary in Siberia, Russia, were monitored and tested to assess their biological, behavioral, and economic traits in a temperate continental climate. We detected significant correlations between the studied biological and behavioral indicators of the bee colony such as colony strength, overwintering ability, infection of colonies with diseases, hygienic behavior, and others. No relationships between the biological and economic (honey productivity) traits of bee colonies are shown. The overall result of our study is that local dark forest bee, A.m.mellifera, showed higher values for all analyzed traits than hybrid colonies. Compared to hybrids, dark forest bee colonies showed more gentleness, productivity, and survivorship. The results from our study indicate a specific local adaptation of the A.m.mellifera subspecies in a temperate continental climate. Siberia represents a unique region for the conservation of the dark forest bee. The creation of conservation areas is one way to protect local bee populations, well adapted to local environmental conditions, from uncontrolled importation of bee breeds from different regions.

Genetic reasons for the migration of the local population bees in Uzbekistan

The article presents the genetic reasons for the emergence of a large number of sources in Uzbekistan, information on the increase of macro- and microelements in the body of migratory bees.

Impact of Outcross Mating on Brood Rearing Activity and Honey Production of Local Honey Bees in Libya

Impact of Outcross Mating on Brood Rearing Activity and Honey Production of Local Honey Bees in Libya

The Effect of Production Method on Local Honeybee Queens, Apis mellifera L. to Determine the Acceptance Rate of Grafted Larvae and Live Weight of Virgin Queens in Latakia Governorate

Asaad, M., M. Omran, N.Z. Hujeij and K. Makis. 2024. The Effect of Production Method on Local Honeybee Queens, Apis mellifera L. to Determine the Acceptance Rate of Grafted Larvae and Live Weight of Virgin Queens in Latakia Governorate. Arab Journal of Plant Protection, 42(2): 155-161. https://doi.org/10.22268/AJPP-001239 This research was conducted at the Scientific Agricultural Research Center in Latakia during 2020 season to study the effect of queen production method (with and without queens) on the acceptance rate of grafted larvae and weight of virgin queens emerging from local bee colonies under the Syrian coast conditions, using wax and plastic cups with dry and wet grafting. The acceptance rate of larvae was 83.33 and 91.66%, and weights of virgin queens were 0.178, 0.198 g in queen rearing colonies with and without queens, respectively, in the wax cups with wet grafting and with a total number of 16 cups/colony, whereas the acceptance rate of larvae was 86.66 and 80.00 % and weights of virgin queens was 0.178 and 0.169 g, respectively, in colonies without or with restricted queens rearing colonies, in the wax cups with wet grafting and a total number of 20 cups/colony. The difference in the average weights of queens in both methods was significant. Keywords: Colonies with queens, queenless colonies, bees, Latakia, Syria.

PKM KELOMPOK TERNAK LEBAH MADU (APIS CERANA) DALAM PENINGKATAN KESEJAHTERAAN KELOMPOK DI DESA BAHA

Apis cerana is a local Asian bee that is distributed almost throughout this continent. Apis cerana is a type of local honey bee that is prone to migration when natural food sources are insufficient. Based on the results of discussions with members of the honey bee group in Baha village, a priority problem that needs to be addressed by group members with assistance from universities can be formulated, namely increasing the ability of group members to be able to adopt appropriate technology for developing honey bees according to required standards so that productivity increases. Adopting technology to reduce mortality rates by using artificial feed. The queen rearing method is used to produce honey bees with high productivity and can carry out post-harvest technology if enough product is produced. The solution offered is to hold outreach. The counseling material concerns: how to develop appropriate, cheap and easy management techniques and develop Apis cerana honey bees, this problem will be informed to honey bee breeders in Baha village, Mengwi sub-district, Badung Regency. Efforts to increase the reproduction and productivity of bees, the application of alternative technology includes the selection of superior seeds and the use/operation of extractor machines in an effort to increase the productivity of bees with their support poles to avoid pests, and how to formulate honey bee animal feed that is cheap, easy to obtain and available in the village. according to livestock needs. After the counseling was carried out, training was carried out for the two groups using three students, such as making colony boxes with supporting poles to avoid pests and diseases of the Apis cerana honey bee.

Study on the Effect of Bee Strain and Insemination Method on the Hygienic Behavior of Bee Colonies Tested Using the Pricking Method

The process of artificial and natural insemination was carried out on the queen bees of the local and Carniolan strains in order to study their hygienic behavior and the Pricking method for the strains, as well as the cross-insemination results between them. The study results showed that the local honey bee strain T1 outperformed the other studied strains in its hygienic behavior, as the detection rate of the dead brood by Pricking was (44.16, 93.16, and 100) % respectively, after (1, 6, and 24) hours of conducting the study. The same strain also outperformed all other strains in removing the dead brood with a percentage ranging from (0.16, 22.66, and 100) % respectively, after (1, 6, and 24) hours of conducting the study. Moreover, the artificial insemination method generally outperformed the natural insemination method in the hygienic behavior of the bee colonies, as the detection rate of the brood in the artificially inseminated bee strains A2 was (40.91, 91.00, 97.33, and 100) % respectively, after (1, 6, 24, and 36) hours of conducting the study. A2 also outperformed the A1 insemination method in terms of the percentage of removing the dead brood by Pricking, with a percentage ranging from (0.00, 17.08, 96.91, and 100) % respectively, after (1, 6, 24, and 36) hours of conducting the study.

Study on the Effect of Bee Strain and Pollination Method on the Hygienic Behavior of Honey Bee Colonies Tested by Liquid Nitrogen Freezing Method

Bee queen breeding was conducted for local and Carniolan honey bee strains, as well as hybrids resulting from cross-pollination, using both natural and artificial insemination methods. The hygienic behavior test was conducted using liquid nitrogen freezing method. The results showed that the hybrid bee strain T3 outperformed with detection and removal rates of 92.66% and 87.50% respectively, 48 hours after the study, regardless of the insemination method. The results also demonstrated the superiority of the natural insemination method, regardless of the studied strain, with detection and removal rates of 85.66% and 78.66% respectively, 48 hours after the killing process. The results also showed the interaction between the bee strain and the insemination method, 48 hours after the killing process, with significant superiority for treatment T2A1 in terms of detection and removal rates at 98.00% and 96.66% respectively. It was followed by treatment T3A2, which had no significant difference in detection rate (94.33%) and a removal rate of 89.00%, which was not significantly different from treatment T3A1 with a removal rate of 86.00%.

Wing morphometry of worker bees of Kharkiv, Sumy and Poltava regions of Ukraine

The affiliation of local bee populations spread across the territory of Ukraine to the subspecies A. m. carnica, A. m. macedonica, A. m. mellifera, and A. m. caucasica has been studied previously in most cases using various phenotypic characteristics, and in some cases, through the study of mitochondrial DNA. According to previous morphometric studies, it was not possible to identify bee families that could be qualified as "purebred". The aim of this study was to investigate three apiaries from different regions of Ukraine where selection measures are systematically carried out to reproduce and preserve the local population of Ukrainian steppe bees, subspecies A. m. macedonica. The goal was to confirm this breeding positioning and find bee families suitable for further breeding work. The study focused on the wing phenotypes of worker bees. In this work, 10 traits were considered as wing phenotypes: seven indices Ci, Dbi, Disc.sh, Ri, Ci.2, Ci.3, Ci.2.1, and three angles A4, E9, J10. Statistical data processing methods and the STATISTICA software package were used as research tools. A total of 5200 wings of worker bees from 53 apiaries in the Kharkiv, Sumy, and Poltava regions were studied. The classification of wings in the Sumy and Poltava regions was carried out into four clusters, while in Kharkiv, it was into three clusters. Preliminary classification based on Euclidean distances using the mean values of traits for individual wing clusters and taking into account the Mahalanobis distances between cluster centroids formed three data arrays labeled as "UkrStep" and "UkrStep.2," which were attributed to the subspecies A. m. macedonica, and "Carnica," attributed to the subspecies A. m. carnica. These can be used as regional standards for studying bee families in this part of Ukraine with the aim of establishing their probable breed. It was found that the population of Ukrainian steppe bees (62.2%) predominates by phenotype on the studied apiaries. For four bee families from the Kuzemin apiary, 92%-100% of worker bees belong to Ukrainian steppe bees. АOn the apiary in Kharkiv, only one bee family had 86% of worker bees belonging to the population of Ukrainian steppe bees. It is recommended to use queens from four bee families for breeding purposes: one queen from the Kharkiv apiary and three queens from the Kuzemin apiary. Key words: Classical morphometry of worker bee wings, discriminant analysis.

Assessing concrete nest boxes for cavity-nesting bees

AbstractArtificial nest boxes for solitary bees and other cavity-nesting Hymenoptera are increasingly used for a variety of purposes, including ecological research, crop pollination support and public outreach. Their attractivity and colonization success by cavity-nesting solitary bees depend on their design and placement, including hole dimensions, orientation and the neighboring habitats and available resources. While most bee nest boxes are made of wooden materials, we assessed here the suitability of perennial, concrete nest boxes for cavity-nesting bees. We carried out a three-year nesting survey of 52 custom-made nest boxes located in 11 different sites throughout France and totaling 2912 available holes of 6, 8, 10 or 12 mm in diameter. Concrete nest boxes successfully attracted reproductive females of solitary bee species and supported successful larval development until the emergence of new individuals. Preferred cavities were the smallest ones (6-8 mm), located at the lowest tested positions above ground (31-47 cm) and oriented southward. Local bee populations established in nest boxes steadily increased throughout the three successive seasons in nearly all study sites. The cavity-nesting bee communities were mostly composed of rather common and generalist species, but also comprised a foraging specialist. Additionally, two cleptoparasitic bee species were detected. All species belonged to the Megachilidae. We further discuss the effects of neighboring urban and natural habitats as potential source or sink of nesting bees, as well as opportunities of concrete nest boxes as tools for urban agriculture and more generally for the new biomimetic urban designs to restore local ecosystem services in cities.

Perg reserve and development of bee colonies of different genealogical formations of the carpathian subspecies

The study of bee colony growth patterns throughout the year makes it possible to substantiate the ways of creating strong families that will ensure high productivity in the collection of bee products. The research was conducted on bees of different genealogical formations of the Carpathian breed in private apiaries in the village of Navariya, Lviv region. To conduct the experimental studies, 6 groups of 10 bee colonies were formed: I – the control group – local bees of the Carpathian population (type “Vuchkovsky”); II – the experimental group – inbred group ♀ UA3-5-9-15.112-2018 x ♂ UA3-5-9-15. 112-2018 (♀ microline “915” x ♂ microline “915”); III – experimental group – breeding cross ♀ UA3-65-2019 x ♂ UA3-5-9-15.112-2018 (♀ microline “Sto” x ♂ microline “915”); IV – experimental group – breeding cross ♀ UA3-5-35-2019 x ♂ UA3-5-9-15. 112-2018 (♀ type “Vuchkovsky” x ♂ microline “915”); V – experimental group – breeding cross ♀ UA3-5-307/67-2018 x ♂ UA3-5-9-15. 112-2018 (♀ microline "67" x ♂ microline “915”); VI – experimental group – breeding cross ♀UA3-5-07-2018 x ♂ UA3-5-9-15.112-2018 (♀ microline “07” x ♂ microline “915”). It was established that bees of different breeding crosses of the Carpathian breed had certain differences in the strength of bee colonies, the number of closed broods, and bee bread productivity. The maximum values of bee colony strength and stocks of perga in all groups were noted during the inspection on 10 June. At the same time, the highest value of bee colony strength was observed in the fifth experimental group (19.7 hives), and the best bee colonies in the second experimental group (6992.0 cells) were found in terms of perg productivity. The highest values of the number of closed brood were recorded during the inspection on 29 May, with the bee colonies of the third experimental group prevailing in this respect (20547.6 cells). Thus, to increase the strength of bee colonies, the number of closed brood, and the bee bread productivity, it is advisable to breed interbreed crosses of the Carpathian subspecies since they are superior to local bees of the Vuchkovsky type in the above characteristics.

In Search of Apis mellifera pomonella in Kazakhstan.

Apis mellifera pomonella is one of two subspecies that represent the eastern limits of honey bee (Apis mellifera) distribution, and it is important to understand its biogeography and evolution. Despite this, A. m. pomonella was not investigated after its discovery 20 years ago. In particular, it is not known if it was hybridized or not with exotic subspecies introduced by beekeepers. In this study, we analysed the variation in honey bee forewing shape in Kazakhstan. Bees were collected from apiaries, where the origin of the queens was not controlled by beekeepers; they formed a group called "local bees", and apiaries where queens declared as either A. m. carnica or A. m. mellifera were obtained from queen breeders. The two later groups were called "exotic bees". We showed that local bees are still distinct from exotic ones. However, some samples showed signs of introgression with exotic subspecies from lineage C. In terms of wing shape, the local bees were most similar to lineage O. We concluded that the local bees most likely represented A. m. pomonella. We provided wing images and identification data, which can help to identify A. m. pomonella and protect it in the future. It is interesting that the nearby honey bee population sourced from China, which is not separated by any clear barrier to gene flow, belonged to lineage M.

Temporal effects of sugar intake on fly local search and honey bee dance behaviour.

Honey bees communicate flight navigational information of profitable food to nestmates via their dance, a small-scale walking pattern, inside the nest. Hungry flies and honey bee foragers exhibit a sugar-elicited search involving path integration that bears a resemblance to dance behaviour. This study aimed to investigate the temporal dynamics of the initiation of sugar-elicited search and dance behaviour, using a comparative approach. Passive displacement experiments showed that feeding and the initiation of search could be spatially and temporally dissociated. Sugar intake increased the probability of initiating a search but the actual onset of walking triggers the path integration system to guide the search. When prevented from walking after feeding, flies and bees maintained their motivation for a path integration-based search for a duration of 3min. In flies, turning and associated characters were significantly reduced during this period but remained higher than in flies without sugar stimulus. These results suggest that sugar elicits two independent behavioural responses: path integration and increased turning, with the initiation and duration of path integration system being temporally restricted. Honey bee dance experiments demonstrated that the motivation of foragers to initiate dance persisted for 15min, while the number of circuits declined after 3min following sugar ingestion. Based on these findings, we propose that food intake during foraging increases the probability to initiate locomotor behaviours involving the path integration system in both flies and honey bees, and this ancestral connection might have been co-opted and elaborated during the evolution of dance communication by honey bees.

An elevational gradient in floral traits and pollinator assemblages in the Neotropical species Costus guanaiensis var. tarmicus in Peru.

Different populations of plant species can adapt to their local pollinators and diverge in floral traits accordingly. Floral traits are subject to pollinator-driven natural selection to enhance plant reproductive success. Studies on temperate plant systems have shown pollinator-driven selection results in floral trait variation along elevational gradients, but studies in tropical systems are lacking. We analyzed floral traits and pollinator assemblages in the Neotropical bee-pollinated taxon Costus guanaiensis var. tarmicus across four sites along a steep elevational gradient in Peru. We found variations in floral traits of size, color, and reward, and in the pollinator assemblage along the elevational gradient. We examined our results considering two hypotheses, (1) local adaptation to different bee assemblages, and (2) the early stages of an evolutionary shift to a new pollinator functional group (hummingbirds). We found some evidence consistent with the adaptation of C. guanaiensis var. tarmicus to the local bee fauna along the studied elevational gradient. Corolla width across sites was associated with bee thorax width of the local most frequent pollinator. However, we could not rule out the possibility of the beginning of a bee-to-hummingbird pollination shift in the highest-studied site. Our study is one of the few geographic-scale analyses of floral trait and pollinator assemblage variation in tropical plant species. Our results broaden our understanding of plant-pollinator interactions beyond temperate systems by showing substantial intraspecific divergence in both floral traits and pollinator assemblages across geographic space in a tropical plant species.