Osmia solitary bees are important pollinators of various crops worldwide.Refrigeration has been widely used to synchronize the emergence time of Osmia species from cocoons with the blooming time of different crops,but...Osmia solitary bees are important pollinators of various crops worldwide.Refrigeration has been widely used to synchronize the emergence time of Osmia species from cocoons with the blooming time of different crops,but the fitness of Osmia after refrigeration remains unknown.Here,the effects of long-term refrigeration at 0℃on the vitality,flight ability,and metabolism of Osmia excavata,which is known as the"king of pollination"in China,were studied.The survival rate(>90%before 120 d),weight loss rate(<15%after 170 d),and mean flight speed of 0.excavata were not greatly affected after long-term refrigeration.The content of fats,which have antifreeze and energy storage properties,was not significantly altered in O.excavata before 130 d of refrigeration,which might explain why the survival rates and flight speed of O.excavata remained high after long-term refrigeration.However,the flight duration and distance decreased significantly(P<0.05),and both were positively correlated with the reduced trehalose levels in 0.excavata(r=[+0.69]-[+0.71];P<0.05).Overall,these findings indicate that the pollination potential of O.excavata for various crops with different flowering periods is high after long-term refrigeration;however,long-term refrigeration may decrease pollination efficiency.Our findings highlight new research directions that could improve the ecological service function of refrigerated O.excavata.展开更多
The effects of enhanced UV-B radiation on the oogenesis and morpho- anatomical characteristics of the European solitary red mason bee Osmia bicornis L. （Hy- menoptera： Megachilidae） were tested under laboratory con...The effects of enhanced UV-B radiation on the oogenesis and morpho- anatomical characteristics of the European solitary red mason bee Osmia bicornis L. （Hy- menoptera： Megachilidae） were tested under laboratory conditions. Cocooned females in the pupal stage were exposed directly to different doses （0, 9.24, 12.32, and 24.64 kJ/m2/d） of artificial UV-B. Our experiments revealed that enhanced UV-B radiation can reduce body mass and fat body content, cause deformities and increase mortality. Following UV exposure at all 3 different doses, the body mass of bees was all significantly reduced compared to the control, with the highest UV dose causing the largest reduction. Similarly, following UV-B radiation, in treated groups the fat body index decreased and the fat body index was the lowest in the group receiving the highest dose of UV radiation. Mortality and morphological deformities, between untreated and exposed females varied considerably and increased with the dose of UV-B radiation. Morphological deformities were mainly manifested in the wings and mouthparts, and occurred more frequently with an increased dose of UV. Cell death was quantified by the Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay （DNA fragmentation） during early stages of oogenesis of O. bicornis females. The bees, after UV-B exposure exhibited more germarium ceils with fragmented DNA. The TUNEL test indicated that in germarium, low doses of UV-B poorly induced the cell death during early development. However, exposure to moderate UV-B dose increased programmed cell death. In females treated with the highest dose of UV-B the vast majority of germarium cells were TUNEL-positive.展开更多
Ecological experiments often require standardized methods that exclude natural variation and allow manipulation of a single parameter. It has been shown that domesticated honey bee larvae are raisable in a controlled ...Ecological experiments often require standardized methods that exclude natural variation and allow manipulation of a single parameter. It has been shown that domesticated honey bee larvae are raisable in a controlled environment. Here we demonstrate that this approach is also transferable to wild solitary bees and wasps without inducing negative effects on their development. Wells may also be supplemented with the antibiotic substance oxytetracycline to control the presence of bacteria. The method thus provides a useful tool to investigate offspring recruitment and larval development in solitary bees and wasps, plus their responses to manipulation of factors as for example diets, toxins and microbiota.展开更多
Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authori...Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authority （EFSA） Guidance on risk assessment of plant protection products （PPP） on bees （Apis mellifera, Bombus spp. and solitary bees）. According to this guidance document, field studies have to be designed to be able to detect significance differences as low as 7% for certain endpoints such as reduction in colony size. This will require an immense number of replicates which is obviously not feasible. In the present study, key endpoints such as mortality, termination rate and number of brood cells in honeybee studies, cocoon production and flight activity in solitary bee studies and number of gynes in bumble bee studies （just to mention some of the endpoints considered） in semi-field studies were analyzed, with Apis mellifera, Bombus terrestris and Osmia bicornis during the past five years （2013-2017）. The results indicate huge differences in the percentage minimal detectable differences （%MDDs） （MDD expressed as median of control value of the endpoint in percent） depending on endpoint and species tested. For honeybee semi-field studies, the lowest %MDDs recorded were between 10% and 15% for the endpoints foraging, number of brood cells and colony strength. The highest %MDDs were observed for the endpoint termination rate, with a %MDD of almost 50%. For the endpoints in bumble bee semi-field studies the %MDDs varied between 17% for bumble bee colony weight and 53% for average mortality during the exposure period in the tunnel. The %MDD for the number of gynes （young queens） was slightly below 25%. For the semi-field solitary bee test system, the %MDDs for the measured endpoints seem to be lower than those for the other two species tested. The %MDDs for the endpoints hatching of offspring, nest occupation and number of cocoons were 8%, 13% and 14%, respectively. Most of the 展开更多
基金supported by the Bee Industry Innovation Team of Shandong Province,National Natural Science Foundation of China(32202316)Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2023D01,CXGC2023F04).
文摘Osmia solitary bees are important pollinators of various crops worldwide.Refrigeration has been widely used to synchronize the emergence time of Osmia species from cocoons with the blooming time of different crops,but the fitness of Osmia after refrigeration remains unknown.Here,the effects of long-term refrigeration at 0℃on the vitality,flight ability,and metabolism of Osmia excavata,which is known as the"king of pollination"in China,were studied.The survival rate(>90%before 120 d),weight loss rate(<15%after 170 d),and mean flight speed of 0.excavata were not greatly affected after long-term refrigeration.The content of fats,which have antifreeze and energy storage properties,was not significantly altered in O.excavata before 130 d of refrigeration,which might explain why the survival rates and flight speed of O.excavata remained high after long-term refrigeration.However,the flight duration and distance decreased significantly(P<0.05),and both were positively correlated with the reduced trehalose levels in 0.excavata(r=[+0.69]-[+0.71];P<0.05).Overall,these findings indicate that the pollination potential of O.excavata for various crops with different flowering periods is high after long-term refrigeration;however,long-term refrigeration may decrease pollination efficiency.Our findings highlight new research directions that could improve the ecological service function of refrigerated O.excavata.
基金This work was supported by a Ministry of Science and Higher Education （N N311 298935） and University of Life Sciences （507.511.29） grants to O.W. and in part by a National Science Foundation Grant （EPS-0903787, MSU#269110-151250） grant to N.K. We would like to thank Agnieszka Graclik for her technical support in im- age analysis and preparation.
文摘The effects of enhanced UV-B radiation on the oogenesis and morpho- anatomical characteristics of the European solitary red mason bee Osmia bicornis L. （Hy- menoptera： Megachilidae） were tested under laboratory conditions. Cocooned females in the pupal stage were exposed directly to different doses （0, 9.24, 12.32, and 24.64 kJ/m2/d） of artificial UV-B. Our experiments revealed that enhanced UV-B radiation can reduce body mass and fat body content, cause deformities and increase mortality. Following UV exposure at all 3 different doses, the body mass of bees was all significantly reduced compared to the control, with the highest UV dose causing the largest reduction. Similarly, following UV-B radiation, in treated groups the fat body index decreased and the fat body index was the lowest in the group receiving the highest dose of UV radiation. Mortality and morphological deformities, between untreated and exposed females varied considerably and increased with the dose of UV-B radiation. Morphological deformities were mainly manifested in the wings and mouthparts, and occurred more frequently with an increased dose of UV. Cell death was quantified by the Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay （DNA fragmentation） during early stages of oogenesis of O. bicornis females. The bees, after UV-B exposure exhibited more germarium ceils with fragmented DNA. The TUNEL test indicated that in germarium, low doses of UV-B poorly induced the cell death during early development. However, exposure to moderate UV-B dose increased programmed cell death. In females treated with the highest dose of UV-B the vast majority of germarium cells were TUNEL-positive.
文摘Ecological experiments often require standardized methods that exclude natural variation and allow manipulation of a single parameter. It has been shown that domesticated honey bee larvae are raisable in a controlled environment. Here we demonstrate that this approach is also transferable to wild solitary bees and wasps without inducing negative effects on their development. Wells may also be supplemented with the antibiotic substance oxytetracycline to control the presence of bacteria. The method thus provides a useful tool to investigate offspring recruitment and larval development in solitary bees and wasps, plus their responses to manipulation of factors as for example diets, toxins and microbiota.
文摘Statistical power, number of replicates and experiment complexity of semi-field and field studies on Apis and non-Apis bee species has become a major issue after publication of the draft European Food Safety Authority （EFSA） Guidance on risk assessment of plant protection products （PPP） on bees （Apis mellifera, Bombus spp. and solitary bees）. According to this guidance document, field studies have to be designed to be able to detect significance differences as low as 7% for certain endpoints such as reduction in colony size. This will require an immense number of replicates which is obviously not feasible. In the present study, key endpoints such as mortality, termination rate and number of brood cells in honeybee studies, cocoon production and flight activity in solitary bee studies and number of gynes in bumble bee studies （just to mention some of the endpoints considered） in semi-field studies were analyzed, with Apis mellifera, Bombus terrestris and Osmia bicornis during the past five years （2013-2017）. The results indicate huge differences in the percentage minimal detectable differences （%MDDs） （MDD expressed as median of control value of the endpoint in percent） depending on endpoint and species tested. For honeybee semi-field studies, the lowest %MDDs recorded were between 10% and 15% for the endpoints foraging, number of brood cells and colony strength. The highest %MDDs were observed for the endpoint termination rate, with a %MDD of almost 50%. For the endpoints in bumble bee semi-field studies the %MDDs varied between 17% for bumble bee colony weight and 53% for average mortality during the exposure period in the tunnel. The %MDD for the number of gynes （young queens） was slightly below 25%. For the semi-field solitary bee test system, the %MDDs for the measured endpoints seem to be lower than those for the other two species tested. The %MDDs for the endpoints hatching of offspring, nest occupation and number of cocoons were 8%, 13% and 14%, respectively. Most of the
