Phylogenetic relationships of 11 bumblebee species,including 5 subgenera:Bombus (5 species),Thoracobombus (3 species),Mendacibombus (1 species),Fervidobombus (1 species) and Pyrobombus (1 species),were analyzed based ...Phylogenetic relationships of 11 bumblebee species,including 5 subgenera:Bombus (5 species),Thoracobombus (3 species),Mendacibombus (1 species),Fervidobombus (1 species) and Pyrobombus (1 species),were analyzed based on the 357?bp mitochondrial cytochrome b gene sequences.There are 65 singleton polymorphic sites and 71 parsimony informative polymorphic sites in this DNA segment,and 45 polymorphic sites within the total 119 translated amino acids segment.Both NJ tree and MP tree show that Mendacibombus (B.avinovielllus) is basal to others,followed by Fervidobombus (B.pensylvanicus);Pyrobombus (B.impatiens) and Bombus are sister subgenera;the subgenus of Bombus is monophyletic,in which B.ignitus diverged first.展开更多
Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the hab...Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the habitat fragmentation and unduly commercial collections. Previous observation showed that this species has very low and even no fruit set, and the pollinators are not observed before this report. The present observation was conducted at the Shennongjia, Hubei Province during the spring of 2002. The results showed that Bombus (Diversobombus) trifasciatus Smith, B. imitator Pittion and one species of Apis visited the flowers of the orchid, but only B. tritasciatus could carry pollinaria on its body and was the legitimate pollinators of C amoena. During 113 h of observation, only nine visitations were recorded. The bumblebees mainly appeared during 12:00-15:00 during the day. Bumblebees stayed in a flower only a few seconds and never more than ten seconds. The flowers would persist in fresh for about three weeks when they were not pollinated, but 3 or 4 d after pollinated, the pollinated flowers underwent a series of color and morphological changes including stalk elongation and ovary swelling. Therefore, stalk elongation can be considered an index of fruits set. Artificial pollination indicated that C amoena is a highly self-compatible and outcrossing species, but dependent on pollinators for fruit set. Based on the field observations, we concluded that pollination system of C amoena is deceptive. The fruit set in nature is not very low (26.98% on average) compared to other deceptive orchids, which may be related to small population sizes. The number of pollinia removal is much higher than that of fruit set, indicating that there are some degrees of pollinia wasting in C amoena.展开更多
Bumblebees are important pollinators in agricultural ecosystems,but their abundance is declining globally.There is an urgent need to protect bumblebee health and their pollination services.Bumblebees possess specializ...Bumblebees are important pollinators in agricultural ecosystems,but their abundance is declining globally.There is an urgent need to protect bumblebee health and their pollination services.Bumblebees possess specialized gut microbiota with potential to be used as probiotics to help defend at-risk bumblebee populations.However,evidence for probiotic benefits on bumblebees is lacking.Here,we evaluated how supplementation with Lactobacillus melliventris isolated from bumblebee gut affected the colony development of Bombus terrestris.This native strain colonized robustly and persisted long-term in bumblebees,leading to a significantly higher quality of offspring.Subsequently,the tyrosine pathway was upregulated in the brain and fat body,while the Wnt and mTOR pathways of the gut were downregulated.Notably,the field experiment in the greenhouse revealed the supplementation of L.melliventris led to a 2.5-fold increase in the bumblebee survival rate and a more than 10%increase in the number of flowers visited,indicating a better health condition and pollination ability in field conditions.Our study represents a first screening for the potential use of the native gut member,L.melliventris,as probiotic strains in hive supplement for bumblebee breeding,which may be a practical approach to improve immunity and hive health.展开更多
Recent developments allowed establishing virtual-reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigat...Recent developments allowed establishing virtual-reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigate the visual learning in the buff-tailed bumble bee Bombus terrestris. Based on responses to appetitive and aversive reinforcements used for conditioning, we show that bumble bees had the proper appetitive motivation to engage in the VR experiments and that they learned efficiently elemental color discriminations. In doing so, they reduced the latency to make a choice, increased the proportion of direct paths toward the virtual stimuli and walked faster toward them. Performance in a short-term retention test showed that bumble bees chose and fixated longer on the correct stimulus in the absence of reinforcement. Body size and weight, although variable across individuals, did not affect cognitive performances and had a mild impact on motor performances. Overall, we show that bumble bees are suitable experimental subjects for experiments on visual learning under VR conditions, which opens important perspectives for invasive studies on the neural and molecular bases of such learning given the robustness of these insects and the accessibility of their brain.展开更多
Social parasitic Hymenopterans have evolved morphological, chemical, and behavioral adaptations to overcome the sophisticated recognition and defense systems of their social host to invade host nests and exploit their...Social parasitic Hymenopterans have evolved morphological, chemical, and behavioral adaptations to overcome the sophisticated recognition and defense systems of their social host to invade host nests and exploit their worker force. In bumblebees, so- cial parasitism appeared in at least 3 subgenera independently： in the subgenus Psithyrus consisting entirely of parasitic species, in the subgenus Alpinobombus with Bombus hy- perboreus, and in the subgenus Thoracobombus with B. inexspectatus. Cuckoo bumblebee males utilize species-specific cephalic labial gland secretions for mating purposes that can impact their inquiline strategy. We performed cephalic labial gland secretions in B. hyperboreus, B. inexspectatus and their hosts. Males of both parasitic species exhibited high species specific levels of cephalic gland secretions, including different main com- pounds. Our results showed no chemical mimicry in the cephalic gland secretions between inquilines and their host and we did not identify the repellent compounds already known in other cuckoo bumblebees.展开更多
Pollen collection is necessary for bee survival and important for flowering plant reproduction, yet if and how pollen extraction motor routines are modified with experience is largely unknown. Here, we used an automat...Pollen collection is necessary for bee survival and important for flowering plant reproduction, yet if and how pollen extraction motor routines are modified with experience is largely unknown. Here, we used an automated reward and monitoring system to evaluate modification in a common pollen-extraction routine, floral sonication. Through a series of laboratory experiments with the bumblebee, Bombus impatiens, we examined whether variation in sonication frequency and acceleration is due to instrumental learning based on rewards, a fixed behavioral response to rewards, and/or a mechanical constraint. We first investigated whether bees could learn to adjust their sonication frequency in response to pollen rewards given only for specified frequency ranges and found no evidenee of instrumental learning. However, we found that absenee versus receipt of a pollen reward did lead to a predictable behavioral resp on se, which depe nded on bee size. Fin ally, we found some evide nee of mechanical con straints, in that flower mass affected sonication acceleration (but not frequency) through an interaction with bee size. In generalz larger bees showed more flexibility in sonication frequency and acceleration, potentially reflecting a size-based constraint on the range over which smaller bees can modify frequency and accelerati on. Overall our results show that although bees did not display instrumental learning of sonication frequency, their sonication motor routine is nevertheless flexible.展开更多
Animals have evolved foraging strategies to acquire blends of nutrients that maximize fitness traits. In social insects, nu trie nt regulation is complicated by the fact that few in dividuals, the foragers, must addre...Animals have evolved foraging strategies to acquire blends of nutrients that maximize fitness traits. In social insects, nu trie nt regulation is complicated by the fact that few in dividuals, the foragers, must address the diverge nt nutritional n eeds of all colony members simulta neously, includi ng other workers, the reproductives, and the brood. Here we used 3D nutritional geometry design to examine how bumblebee workers regulate their collection of 3 major macronutrients in the presence and absenee of brood. We provided small colonies artificial nectars (liquid diets) and pollens (solid diets) varying in their compositions of proteins, lipids, and carbohydrates during 2 weeks. Colo nies give n a choice betwee n nutrition ally complementary diets self-selected foods to reach a target ratio of 71% proteins, 6% carbohydrates, and 23% lipids, irrespective of the presenee of brood. Whe n con fined to a single nutrition ally imbalanced solid diet, colonies without brood regulated lipid collection and over-collected protein relative to this target ratio, whereas colonies with brood regulated both lipid and protein collection. This brood effect on the regulation of nutrient collection by workers suggests that protein levels are critical for larval development. Our results highlight the importa nee of con sidering bee nu trition as a multidimensi onal phe no men on to better assess the effects of environmental impoverishment and malnutrition on population declines.展开更多
文摘Phylogenetic relationships of 11 bumblebee species,including 5 subgenera:Bombus (5 species),Thoracobombus (3 species),Mendacibombus (1 species),Fervidobombus (1 species) and Pyrobombus (1 species),were analyzed based on the 357?bp mitochondrial cytochrome b gene sequences.There are 65 singleton polymorphic sites and 71 parsimony informative polymorphic sites in this DNA segment,and 45 polymorphic sites within the total 119 translated amino acids segment.Both NJ tree and MP tree show that Mendacibombus (B.avinovielllus) is basal to others,followed by Fervidobombus (B.pensylvanicus);Pyrobombus (B.impatiens) and Bombus are sister subgenera;the subgenus of Bombus is monophyletic,in which B.ignitus diverged first.
文摘Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the habitat fragmentation and unduly commercial collections. Previous observation showed that this species has very low and even no fruit set, and the pollinators are not observed before this report. The present observation was conducted at the Shennongjia, Hubei Province during the spring of 2002. The results showed that Bombus (Diversobombus) trifasciatus Smith, B. imitator Pittion and one species of Apis visited the flowers of the orchid, but only B. tritasciatus could carry pollinaria on its body and was the legitimate pollinators of C amoena. During 113 h of observation, only nine visitations were recorded. The bumblebees mainly appeared during 12:00-15:00 during the day. Bumblebees stayed in a flower only a few seconds and never more than ten seconds. The flowers would persist in fresh for about three weeks when they were not pollinated, but 3 or 4 d after pollinated, the pollinated flowers underwent a series of color and morphological changes including stalk elongation and ovary swelling. Therefore, stalk elongation can be considered an index of fruits set. Artificial pollination indicated that C amoena is a highly self-compatible and outcrossing species, but dependent on pollinators for fruit set. Based on the field observations, we concluded that pollination system of C amoena is deceptive. The fruit set in nature is not very low (26.98% on average) compared to other deceptive orchids, which may be related to small population sizes. The number of pollinia removal is much higher than that of fruit set, indicating that there are some degrees of pollinia wasting in C amoena.
基金supported by the National Natural Science Foundation of China Project 32200387.
文摘Bumblebees are important pollinators in agricultural ecosystems,but their abundance is declining globally.There is an urgent need to protect bumblebee health and their pollination services.Bumblebees possess specialized gut microbiota with potential to be used as probiotics to help defend at-risk bumblebee populations.However,evidence for probiotic benefits on bumblebees is lacking.Here,we evaluated how supplementation with Lactobacillus melliventris isolated from bumblebee gut affected the colony development of Bombus terrestris.This native strain colonized robustly and persisted long-term in bumblebees,leading to a significantly higher quality of offspring.Subsequently,the tyrosine pathway was upregulated in the brain and fat body,while the Wnt and mTOR pathways of the gut were downregulated.Notably,the field experiment in the greenhouse revealed the supplementation of L.melliventris led to a 2.5-fold increase in the bumblebee survival rate and a more than 10%increase in the number of flowers visited,indicating a better health condition and pollination ability in field conditions.Our study represents a first screening for the potential use of the native gut member,L.melliventris,as probiotic strains in hive supplement for bumblebee breeding,which may be a practical approach to improve immunity and hive health.
文摘Recent developments allowed establishing virtual-reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigate the visual learning in the buff-tailed bumble bee Bombus terrestris. Based on responses to appetitive and aversive reinforcements used for conditioning, we show that bumble bees had the proper appetitive motivation to engage in the VR experiments and that they learned efficiently elemental color discriminations. In doing so, they reduced the latency to make a choice, increased the proportion of direct paths toward the virtual stimuli and walked faster toward them. Performance in a short-term retention test showed that bumble bees chose and fixated longer on the correct stimulus in the absence of reinforcement. Body size and weight, although variable across individuals, did not affect cognitive performances and had a mild impact on motor performances. Overall, we show that bumble bees are suitable experimental subjects for experiments on visual learning under VR conditions, which opens important perspectives for invasive studies on the neural and molecular bases of such learning given the robustness of these insects and the accessibility of their brain.
文摘Social parasitic Hymenopterans have evolved morphological, chemical, and behavioral adaptations to overcome the sophisticated recognition and defense systems of their social host to invade host nests and exploit their worker force. In bumblebees, so- cial parasitism appeared in at least 3 subgenera independently： in the subgenus Psithyrus consisting entirely of parasitic species, in the subgenus Alpinobombus with Bombus hy- perboreus, and in the subgenus Thoracobombus with B. inexspectatus. Cuckoo bumblebee males utilize species-specific cephalic labial gland secretions for mating purposes that can impact their inquiline strategy. We performed cephalic labial gland secretions in B. hyperboreus, B. inexspectatus and their hosts. Males of both parasitic species exhibited high species specific levels of cephalic gland secretions, including different main com- pounds. Our results showed no chemical mimicry in the cephalic gland secretions between inquilines and their host and we did not identify the repellent compounds already known in other cuckoo bumblebees.
文摘Pollen collection is necessary for bee survival and important for flowering plant reproduction, yet if and how pollen extraction motor routines are modified with experience is largely unknown. Here, we used an automated reward and monitoring system to evaluate modification in a common pollen-extraction routine, floral sonication. Through a series of laboratory experiments with the bumblebee, Bombus impatiens, we examined whether variation in sonication frequency and acceleration is due to instrumental learning based on rewards, a fixed behavioral response to rewards, and/or a mechanical constraint. We first investigated whether bees could learn to adjust their sonication frequency in response to pollen rewards given only for specified frequency ranges and found no evidenee of instrumental learning. However, we found that absenee versus receipt of a pollen reward did lead to a predictable behavioral resp on se, which depe nded on bee size. Fin ally, we found some evide nee of mechanical con straints, in that flower mass affected sonication acceleration (but not frequency) through an interaction with bee size. In generalz larger bees showed more flexibility in sonication frequency and acceleration, potentially reflecting a size-based constraint on the range over which smaller bees can modify frequency and accelerati on. Overall our results show that although bees did not display instrumental learning of sonication frequency, their sonication motor routine is nevertheless flexible.
文摘Animals have evolved foraging strategies to acquire blends of nutrients that maximize fitness traits. In social insects, nu trie nt regulation is complicated by the fact that few in dividuals, the foragers, must address the diverge nt nutritional n eeds of all colony members simulta neously, includi ng other workers, the reproductives, and the brood. Here we used 3D nutritional geometry design to examine how bumblebee workers regulate their collection of 3 major macronutrients in the presence and absenee of brood. We provided small colonies artificial nectars (liquid diets) and pollens (solid diets) varying in their compositions of proteins, lipids, and carbohydrates during 2 weeks. Colo nies give n a choice betwee n nutrition ally complementary diets self-selected foods to reach a target ratio of 71% proteins, 6% carbohydrates, and 23% lipids, irrespective of the presenee of brood. Whe n con fined to a single nutrition ally imbalanced solid diet, colonies without brood regulated lipid collection and over-collected protein relative to this target ratio, whereas colonies with brood regulated both lipid and protein collection. This brood effect on the regulation of nutrient collection by workers suggests that protein levels are critical for larval development. Our results highlight the importa nee of con sidering bee nu trition as a multidimensi onal phe no men on to better assess the effects of environmental impoverishment and malnutrition on population declines.
