Samples of workers of honeybee were collected from 42 colonies in 13 localities in the Lake Chad Basin (parts of Cameroon, Chad, and Nigeria) and analysed using classical morphometry. Measurements of 35 morphological ...Samples of workers of honeybee were collected from 42 colonies in 13 localities in the Lake Chad Basin (parts of Cameroon, Chad, and Nigeria) and analysed using classical morphometry. Measurements of 35 morphological characters of body size, colour and pilosity were taken from 10 workers per colony and the data subjected to one-way analysis of variance (ANOVA), principal components analysis (PCA), hierarchical cluster analysis (HCA), stepwise discriminant analysis (DA) and Pearson’s product-moment correlation analysis. A one-way ANOVA revealed that means of 21 of the morphometric characters differed significantly (p 0.05). The bees formed one cluster in a PCA. However, scatter plots of altitude against principal component 1 of PCA (loaded with characters of body size) revealed an increase of size of the bees along the gradient of the Lake Chad Basin. The coefficient of determination (R2) indicated that 88% and 77% of the variation in size might be explained by altitude in the southeastern and southwestern parts of the basin, respectively. Additionally, there was a very highly significant strong positive relationship between principal component 1 and altitude (r(30) = 0.618, p < 0.0005). Similarly, HCA and DA classified the colonies into three morphoclusters whose distribution closely followed the altitude of the area.展开更多
Apis mellifera filamentous virus(Am FV)is a large DNA virus that is endemic in honeybee colonies.The genome sequence of the Am FV Swiss isolate(Am FV CH–C05)has been reported,but so far very few molecular studies hav...Apis mellifera filamentous virus(Am FV)is a large DNA virus that is endemic in honeybee colonies.The genome sequence of the Am FV Swiss isolate(Am FV CH–C05)has been reported,but so far very few molecular studies have been conducted on this virus.In this study,we isolated and purified Am FV(Am FV CN)from Chinese honeybee(Apis mellifera)colonies and elucidated its genomics and proteomics.Electron microscopy showed ovoid purified virions with dimensions of 300–500×210–285 nm,wrapping a 3165×40 nm filamentous nucleocapsid in three figure-eight loops.Unlike Am FV CH–C05,which was reported to have a circular genome,our data suggest that Am FV CN has a linear genome of approximately 493 kb.A total of 197 ORFs were identified,among which36 putative genes including 18 baculoviral homologs were annotated.The overall nucleotide similarity between the CN and CH–C05 isolates was 96.9%.Several ORFs were newly annotated in Am FV CN,including homologs of per os infectivity factor 4(PIF4)and a putative integrase.Phylogenomic analysis placed Am FVs on a separate branch within the newly proposed virus class Naldaviricetes.Proteomic analysis revealed 47 Am FV virionassociated proteins,of which 14 had over 50%sequence coverage,suggesting that they are likely to be main structural proteins.In addition,all six of the annotated PIFs(PIF-0–5)were identified by proteomics,suggesting that they may function as entry factors in Am FV infection.This study provides fundamental information regarding the molecular biology of Am FV.展开更多
Nutrition contributes to honey bee caste differentiation,but the role of individual nutrients is still unclear.Most essential amino acid contents,except that of methionine(Met),are greater in royal jelly than worker j...Nutrition contributes to honey bee caste differentiation,but the role of individual nutrients is still unclear.Most essential amino acid contents,except that of methionine(Met),are greater in royal jelly than worker jelly.After〜3.5 i the Met content in the latter was slightly greater than in the former.Met is the major raw material used in the synthesis of S-adenosyl-L-methionine,an active methyl donor for DNA methylation,which is an epigenetic driver of caste differentiation.Here,we tested whether Met regulates caste differentiation in honey bees by determining its effects on the caste development of bees receiving four diets:the basic,basic+0.2%Met,basic+0.2%Met+20 mg/kg 5-azacytidine,and basic+20 mg/kg 5-azacytidine.The presence of Met decreased the adult bee body length and the numbers of ovarioles,indicating that Met may direct the development of female larvae toward worker bees.The upregulated expression of SAMS,Dnmtl,and Dnmt3 caused by Met exposure in 4-d-old larvae indicated that the worker-inductive effects of Met may occur through the promotion of DNA methylation.We investigated the co-effects of Met and glucose on bee development,and found that the effects of an increased glucose level on the number of ovarioles and body length did not strengthen the worker-inductive effects caused by Met.Our results contribute to caste development theory and suggest that Met-as a methyl donor一plays a regulatory,but not decisive,role in caste differentiation.展开更多
Animals use diverse sensory stimuli to navigate their environment and to recognize rewarding food sources.Honey bees use visual atributes of the targeted food source,such as its color,shape,size,direction and distance...Animals use diverse sensory stimuli to navigate their environment and to recognize rewarding food sources.Honey bees use visual atributes of the targeted food source,such as its color,shape,size,direction and distance from the hive,and the landmarks around it to navigate during foraging.They transmit the location information of the food source to other bees if it is highly rewarding.To investigate the relative importance of these attributes,we trained bees to feeders in two different experiments.In the first experiment,we asked whether bees prefer to land on(a)a similar feeder at a different distance on the same heading or on(b)a visually distinct feeder located at the exact same location.We found that,within a short foraging range,bees relied heavily on the color and the shape of the food source and to a lesser extent on its distance from the hive.In the second experiment,we asked if moving the main landmark or the feeder(visual target)influenced recruitment dancing for the feeder.We found that foragers took longer to land and danced fewer circuits when the location of the food source,or a major landmark associated with it,changed.These results demonstrate that prominent visual atributes of food sources and landmarks are evidently more reliable than distance information and that foraging bees heavily utilize these visual cues at the later stages of their journey.展开更多
Aims Worldwide,evidence suggests that exotic pollinators can disrupt plant mating patterns.However,few studies have determined if pol-lination by the honeybee Apis mellifera(the world’s most widely introduced pollina...Aims Worldwide,evidence suggests that exotic pollinators can disrupt plant mating patterns.However,few studies have determined if pol-lination by the honeybee Apis mellifera(the world’s most widely introduced pollinator)reduces offspring quality when compared with pollination by native birds.The Australian Proteaceae provides an excellent opportunity to test the impact of honeybees in pol-lination systems that are adapted to birds and non-flying mammals.Methods We compared the frequency of flower visitation and foraging behav-iour of birds and insects within seven populations of Banksia erici-folia.Banksia ericifolia is hermaphroditic and has large nectar-rich,orange inflorescences typical of bird and mammal pollinated spe-cies.For a subset of the study populations,we compared the qual-ity of seed produced via an exclusion treatment(that only allowed invertebrates to access flowers)with an open-pollination treatment(potentially visited by mammals,birds and invertebrates),by meas-uring seed weight,germination rates(T50),percent germination,seedling height after 14 days since the emergence of the cotyledon and time to emergence of the cotyledon.Important Findings Apis mellifera was the only apparent insect pollinator and the most frequent flower visitor,while the open treatment inflorescences were also frequently visited by avian pollinators,primarily hone-yeater species.The foraging behaviour of honeybees and honeyeat-ers showed striking differences that potentially affect patterns of pollen transfer.Honeybees made significantly greater proportions of within cf.among plant movements and only 30%(n=48)of honeybees foraged for pollen(nectar foragers carried no pollen)whilst all birds were observed to contact both stigmas and anthers when foraging for nectar.Despite these fundamental differences in behaviour,there was little effect of treatment on seed set or qual-ity.Our data show that while honeybees appear to alter patterns of pollen transfer within B.ericifolia populations,they do not impact reproductive rates or performance of early life-stages.展开更多
Background:Climate change creates opportune conditions that favour the spread of pests and diseases outside their known active range.Modelling climate change scenarios is oftentimes useful tool to assess the climate a...Background:Climate change creates opportune conditions that favour the spread of pests and diseases outside their known active range.Modelling climate change scenarios is oftentimes useful tool to assess the climate analogues to unveil the potential risk of spreading suitability conditions for pests and diseases and hence allows development of appropriate responses to address the impending challenge.In the current study,we modelled the impact of climate change on the distribution of Varroa destructor,a parasitic mite that attacks all life forms of honey bees and remains a significant threat to their survival and productivity of bee products in Tanzania and elsewhere.Methods:The data about the presence of V.destructor were collected in eight regions of Tanzania selected in consideration of several factors including potentials for beekeeping activities,elevation(highlands vs.lowlands)and differences in climatic conditions.A total of 19 bioclimatic datasets covering the entire country were used for developing climate scenarios of mid-century 2055 and late-century 2085 for both rcp4.5 and rcp8.5.We thereafter modelled the current and future risk distribution of V.destructor using MaxEnt.Results:The results indicated a model performance of AUC=0.85,with mean diurnal range in temperature(Bio2,43.9%),mean temperature(Bio1,20.6%)and mean annual rainfall(Bio12,11.7%)as the important variables.Future risk projections indicated mixed responses of the potential risk of spreads of V.destructor,exhibiting both decrease and increases in the mid-century 2055 and late-century 2085 on different sites.Overall,there is a general decline of highly suitable areas of V.destructor in mid-and late-century across all scenarios(rcp4.5 and rcp8.5).The moderately suitable areas indicated a mixed response in mid-century with decline(under rcp4.5)and increase(under rcp8.5)and consistent increase in late century.The marginally suitable areas show a decline in mid-century and increase in late-century.Our results suggest that the climate change will continue to significantly affect the distribution and risks spread of V.destructor in Tanzania.The suitability range of V.destructor will shift where highly suitable areas will be diminishing to the advantage of the honey bees’populations,but increase of moderately suitable sites indicates an expansion to new areas.The late century projections show the increased risks due to surge in the moderate and marginal suitability which means expansion in the areas where V.destructor will operate Conclusion:The current and predicted areas of habitat suitability for V.destructor’s host provides information useful for beekeeping stakeholders in Tanzania to consider the impending risks and allow adequate interventions to address challenges facing honey bees and the beekeeping industry.We recommend further studies on understanding the severity of V.destructor in health and stability of the honey bees in Tanzania.This will provide a better picture on how the country will need to monitor and reduce the risks associated with the increase of V.destructor activities as triggered by climate change.The loss of honey bees’colonies and its subsequent impact in bees’products production and pollination effect have both ecological and economic implications that need to have prioritization by the stakeholders in the country to address the challenge of spreading V.destructor.展开更多
文摘Samples of workers of honeybee were collected from 42 colonies in 13 localities in the Lake Chad Basin (parts of Cameroon, Chad, and Nigeria) and analysed using classical morphometry. Measurements of 35 morphological characters of body size, colour and pilosity were taken from 10 workers per colony and the data subjected to one-way analysis of variance (ANOVA), principal components analysis (PCA), hierarchical cluster analysis (HCA), stepwise discriminant analysis (DA) and Pearson’s product-moment correlation analysis. A one-way ANOVA revealed that means of 21 of the morphometric characters differed significantly (p 0.05). The bees formed one cluster in a PCA. However, scatter plots of altitude against principal component 1 of PCA (loaded with characters of body size) revealed an increase of size of the bees along the gradient of the Lake Chad Basin. The coefficient of determination (R2) indicated that 88% and 77% of the variation in size might be explained by altitude in the southeastern and southwestern parts of the basin, respectively. Additionally, there was a very highly significant strong positive relationship between principal component 1 and altitude (r(30) = 0.618, p < 0.0005). Similarly, HCA and DA classified the colonies into three morphoclusters whose distribution closely followed the altitude of the area.
基金the Open Research Fund Program of the State Key Laboratory of Virology of China(Grant No.2019IOV004)the key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SMC021)the National Natural Science Foundation of China(Grant No.31900154 and 31572471)。
文摘Apis mellifera filamentous virus(Am FV)is a large DNA virus that is endemic in honeybee colonies.The genome sequence of the Am FV Swiss isolate(Am FV CH–C05)has been reported,but so far very few molecular studies have been conducted on this virus.In this study,we isolated and purified Am FV(Am FV CN)from Chinese honeybee(Apis mellifera)colonies and elucidated its genomics and proteomics.Electron microscopy showed ovoid purified virions with dimensions of 300–500×210–285 nm,wrapping a 3165×40 nm filamentous nucleocapsid in three figure-eight loops.Unlike Am FV CH–C05,which was reported to have a circular genome,our data suggest that Am FV CN has a linear genome of approximately 493 kb.A total of 197 ORFs were identified,among which36 putative genes including 18 baculoviral homologs were annotated.The overall nucleotide similarity between the CN and CH–C05 isolates was 96.9%.Several ORFs were newly annotated in Am FV CN,including homologs of per os infectivity factor 4(PIF4)and a putative integrase.Phylogenomic analysis placed Am FVs on a separate branch within the newly proposed virus class Naldaviricetes.Proteomic analysis revealed 47 Am FV virionassociated proteins,of which 14 had over 50%sequence coverage,suggesting that they are likely to be main structural proteins.In addition,all six of the annotated PIFs(PIF-0–5)were identified by proteomics,suggesting that they may function as entry factors in Am FV infection.This study provides fundamental information regarding the molecular biology of Am FV.
基金Funds of Shandong Province"Double Tops"Program(2016-2020)Shandong Province Agricultural Fine Varieties Breeding Projects(2017LZN006)the earmarked fund for the China Agriculture Research System(No.CARS-44).
文摘Nutrition contributes to honey bee caste differentiation,but the role of individual nutrients is still unclear.Most essential amino acid contents,except that of methionine(Met),are greater in royal jelly than worker jelly.After〜3.5 i the Met content in the latter was slightly greater than in the former.Met is the major raw material used in the synthesis of S-adenosyl-L-methionine,an active methyl donor for DNA methylation,which is an epigenetic driver of caste differentiation.Here,we tested whether Met regulates caste differentiation in honey bees by determining its effects on the caste development of bees receiving four diets:the basic,basic+0.2%Met,basic+0.2%Met+20 mg/kg 5-azacytidine,and basic+20 mg/kg 5-azacytidine.The presence of Met decreased the adult bee body length and the numbers of ovarioles,indicating that Met may direct the development of female larvae toward worker bees.The upregulated expression of SAMS,Dnmtl,and Dnmt3 caused by Met exposure in 4-d-old larvae indicated that the worker-inductive effects of Met may occur through the promotion of DNA methylation.We investigated the co-effects of Met and glucose on bee development,and found that the effects of an increased glucose level on the number of ovarioles and body length did not strengthen the worker-inductive effects caused by Met.Our results contribute to caste development theory and suggest that Met-as a methyl donor一plays a regulatory,but not decisive,role in caste differentiation.
文摘Animals use diverse sensory stimuli to navigate their environment and to recognize rewarding food sources.Honey bees use visual atributes of the targeted food source,such as its color,shape,size,direction and distance from the hive,and the landmarks around it to navigate during foraging.They transmit the location information of the food source to other bees if it is highly rewarding.To investigate the relative importance of these attributes,we trained bees to feeders in two different experiments.In the first experiment,we asked whether bees prefer to land on(a)a similar feeder at a different distance on the same heading or on(b)a visually distinct feeder located at the exact same location.We found that,within a short foraging range,bees relied heavily on the color and the shape of the food source and to a lesser extent on its distance from the hive.In the second experiment,we asked if moving the main landmark or the feeder(visual target)influenced recruitment dancing for the feeder.We found that foragers took longer to land and danced fewer circuits when the location of the food source,or a major landmark associated with it,changed.These results demonstrate that prominent visual atributes of food sources and landmarks are evidently more reliable than distance information and that foraging bees heavily utilize these visual cues at the later stages of their journey.
基金ARC Linkage Grant(ARC LP100100672 to D.J.A.and A.J.D.)University of Wollongong.
文摘Aims Worldwide,evidence suggests that exotic pollinators can disrupt plant mating patterns.However,few studies have determined if pol-lination by the honeybee Apis mellifera(the world’s most widely introduced pollinator)reduces offspring quality when compared with pollination by native birds.The Australian Proteaceae provides an excellent opportunity to test the impact of honeybees in pol-lination systems that are adapted to birds and non-flying mammals.Methods We compared the frequency of flower visitation and foraging behav-iour of birds and insects within seven populations of Banksia erici-folia.Banksia ericifolia is hermaphroditic and has large nectar-rich,orange inflorescences typical of bird and mammal pollinated spe-cies.For a subset of the study populations,we compared the qual-ity of seed produced via an exclusion treatment(that only allowed invertebrates to access flowers)with an open-pollination treatment(potentially visited by mammals,birds and invertebrates),by meas-uring seed weight,germination rates(T50),percent germination,seedling height after 14 days since the emergence of the cotyledon and time to emergence of the cotyledon.Important Findings Apis mellifera was the only apparent insect pollinator and the most frequent flower visitor,while the open treatment inflorescences were also frequently visited by avian pollinators,primarily hone-yeater species.The foraging behaviour of honeybees and honeyeat-ers showed striking differences that potentially affect patterns of pollen transfer.Honeybees made significantly greater proportions of within cf.among plant movements and only 30%(n=48)of honeybees foraged for pollen(nectar foragers carried no pollen)whilst all birds were observed to contact both stigmas and anthers when foraging for nectar.Despite these fundamental differences in behaviour,there was little effect of treatment on seed set or qual-ity.Our data show that while honeybees appear to alter patterns of pollen transfer within B.ericifolia populations,they do not impact reproductive rates or performance of early life-stages.
文摘Background:Climate change creates opportune conditions that favour the spread of pests and diseases outside their known active range.Modelling climate change scenarios is oftentimes useful tool to assess the climate analogues to unveil the potential risk of spreading suitability conditions for pests and diseases and hence allows development of appropriate responses to address the impending challenge.In the current study,we modelled the impact of climate change on the distribution of Varroa destructor,a parasitic mite that attacks all life forms of honey bees and remains a significant threat to their survival and productivity of bee products in Tanzania and elsewhere.Methods:The data about the presence of V.destructor were collected in eight regions of Tanzania selected in consideration of several factors including potentials for beekeeping activities,elevation(highlands vs.lowlands)and differences in climatic conditions.A total of 19 bioclimatic datasets covering the entire country were used for developing climate scenarios of mid-century 2055 and late-century 2085 for both rcp4.5 and rcp8.5.We thereafter modelled the current and future risk distribution of V.destructor using MaxEnt.Results:The results indicated a model performance of AUC=0.85,with mean diurnal range in temperature(Bio2,43.9%),mean temperature(Bio1,20.6%)and mean annual rainfall(Bio12,11.7%)as the important variables.Future risk projections indicated mixed responses of the potential risk of spreads of V.destructor,exhibiting both decrease and increases in the mid-century 2055 and late-century 2085 on different sites.Overall,there is a general decline of highly suitable areas of V.destructor in mid-and late-century across all scenarios(rcp4.5 and rcp8.5).The moderately suitable areas indicated a mixed response in mid-century with decline(under rcp4.5)and increase(under rcp8.5)and consistent increase in late century.The marginally suitable areas show a decline in mid-century and increase in late-century.Our results suggest that the climate change will continue to significantly affect the distribution and risks spread of V.destructor in Tanzania.The suitability range of V.destructor will shift where highly suitable areas will be diminishing to the advantage of the honey bees’populations,but increase of moderately suitable sites indicates an expansion to new areas.The late century projections show the increased risks due to surge in the moderate and marginal suitability which means expansion in the areas where V.destructor will operate Conclusion:The current and predicted areas of habitat suitability for V.destructor’s host provides information useful for beekeeping stakeholders in Tanzania to consider the impending risks and allow adequate interventions to address challenges facing honey bees and the beekeeping industry.We recommend further studies on understanding the severity of V.destructor in health and stability of the honey bees in Tanzania.This will provide a better picture on how the country will need to monitor and reduce the risks associated with the increase of V.destructor activities as triggered by climate change.The loss of honey bees’colonies and its subsequent impact in bees’products production and pollination effect have both ecological and economic implications that need to have prioritization by the stakeholders in the country to address the challenge of spreading V.destructor.
