scholarly journals Resistance to amitraz in the parasitic honey bee mite Varroa destructor is associated with mutations in the β-adrenergic-like octopamine receptor

2021 ◽  
Author(s):  
Carmen Sara Hernández-Rodríguez ◽  
Sara Moreno-Martí ◽  
Gabrielle Almecija ◽  
Krisztina Christmon ◽  
Josephine D. Johnson ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Loss Rate ◽  
Colony Losses ◽  
High Loss ◽  
Diagnostic Assays ◽  
Treatment Regimens ◽  
Evolution Of Resistance ◽  
Octopamine Receptor ◽  
High Loss Rate

Varroa destructor is considered a major reason for high loss rate of Western honey bee (Apis mellifera) colonies. To prevent colony losses caused by V. destructor it is necessary to actively manage the mite population. Beekeepers, particularly commercial beekeepers, have few alternative treatments other than synthetic acaricides to control the parasite, resulting in intensive treatment regimens that led to the evolution of resistance in mite populations. To investigate the mechanism of the resistance to amitraz detected in V. destructor mites from French and U.S. apiaries, we identified and characterized octopamine and tyramine receptors (the known targets of amitraz) in this species. The comparison of sequences obtained from mites collected from different apiaries with different treatment regimens, showed that the amino acid substitutions N87S or Y215H in the OctβR were associated with treatment failures reported in French or U.S. apiaries, respectively. Based on our findings, we have developed and tested two high throughput diagnostic assays based on TaqMan® able to accurately detect mites carrying the mutations in this receptor. This valuable information may be of help for beekeepers when selecting the most suitable acaricide to manage V. destructor.

scholarly journals Resistance to amitraz in the parasitic honey bee mite Varroa destructor is associated with mutations in the β-adrenergic-like octopamine receptor

2021 ◽  
Author(s):  
Carmen Sara Hernández-Rodríguez ◽  
Sara Moreno-Martí ◽  
Gabrielle Almecija ◽  
Krisztina Christmon ◽  
Josephine D. Johnson ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Colony Losses ◽  
High Loss ◽  
Diagnostic Assays ◽  
Treatment Regimens ◽  
Taqman Technology ◽  
Evolution Of Resistance ◽  
Octopamine Receptor ◽  
High Loss Rate

AbstractVarroa destructor is considered a major reason for high loss rate of Western honey bee (Apis mellifera) colonies. To prevent colony losses caused by V. destructor, it is necessary to actively manage the mite population. Beekeepers, particularly commercial beekeepers, have few alternative treatments other than synthetic acaricides to control the parasite, resulting in intensive treatment regimens that led to the evolution of resistance in mite populations. To investigate the mechanism of the resistance to amitraz detected in V. destructor mites from French and U.S. apiaries, we identified and characterized octopamine and tyramine receptors (the known targets of amitraz) in this species. The comparison of sequences obtained from mites collected from different apiaries with different treatment regimens, showed that the amino acid substitutions N87S or Y215H in the OctβR were associated with treatment failures reported in French or U.S. apiaries, respectively. Based on our findings, we have developed and tested two high throughput diagnostic assays based on TaqMan technology able to accurately detect mites carrying the mutations in this receptor. This valuable information may be of help for beekeepers when selecting the most suitable acaricide to manage V. destructor.

scholarly journals Potential distribution of the endangered endemic lizard Liolaemus lutzae Mertens, 1938 (Liolaemidae): are there other suitable areas for a geographically restricted species?

2014 ◽  
Vol 74 (2) ◽  
pp. 338-348 ◽  
Author(s):  
GR. Winck ◽  
P. Almeida-Santos ◽  
CFD. Rocha
Keyword(s):  
Geographic Distribution ◽  
Diurnal Temperature Range ◽  
Potential Distribution ◽  
Sand Dune ◽  
Loss Rate ◽  
Distribution Area ◽  
Environmental Matrices ◽  
High Loss ◽  
Original Distribution ◽  
High Loss Rate

In this study we attempted to access further information on the geographical distribution of the endangered lizard Liolaemus lutzae, estimating its potential distribution through the maximum entropy algorithm. For this purpose, we related its points of occurrence with matrices of environmental variables. After examining the correlation between environmental matrices, we selected 10 for model construction. The main variables influencing the current geographic distribution of L. lutzae were the diurnal temperature range and altitude. The species endemism seemed to be a consequence of a reduction of the original distribution area. Alternatively, the resulting model may reflect the geographic distribution of an ancestral lineage, since the model selected areas of occurrence of the two other species of Liolaemus from Brazil (L. arambarensis and L. occipitalis), all living in sand dune habitats and having psamophilic habits. Due to the high loss rate of habitat occupied by the species, the conservation and recovery of the remaining areas affected by human actions is essential.

scholarly journals Advances and perspectives in selecting resistance traits against the parasitic mite Varroa destructor in honey bees

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Matthieu Guichard ◽  
Vincent Dietemann ◽  
Markus Neuditschko ◽  
Benjamin Dainat
Keyword(s):  
Honey Bee ◽  
Environmental Effects ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Selection Strategy ◽  
Pollination Services ◽  
Colony Losses ◽  
New Host ◽  
Parasitic Mite ◽  
Resistance Traits

Abstract Background In spite of the implementation of control strategies in honey bee (Apis mellifera) keeping, the invasive parasitic mite Varroa destructor remains one of the main causes of colony losses in numerous countries. Therefore, this parasite represents a serious threat to beekeeping and agro-ecosystems that benefit from the pollination services provided by honey bees. To maintain their stocks, beekeepers have to treat their colonies with acaricides every year. Selecting lineages that are resistant to infestations is deemed to be a more sustainable approach. Review Over the last three decades, numerous selection programs have been initiated to improve the host–parasite relationship and to support honey bee survival in the presence of the parasite without the need for acaricide treatments. Although resistance traits have been included in the selection strategy of honey bees, it has not been possible to globally solve the V. destructor problem. In this study, we review the literature on the reasons that have potentially limited the success of such selection programs. We compile the available information to assess the relevance of selected traits and the potential environmental effects that distort trait expression and colony survival. Limitations to the implementation of these traits in the field are also discussed. Conclusions Improving our knowledge of the mechanisms underlying resistance to V. destructor to increase trait relevance, optimizing selection programs to reduce environmental effects, and communicating selection outcomes are all crucial to efforts aiming at establishing a balanced relationship between the invasive parasite and its new host.

The Reason Statistics and Analysis of the Loss of Hotel Employees

2014 ◽  
Vol 926-930 ◽  
pp. 4138-4141
Author(s):  
Lei Lei Wang ◽  
Wen Su Xu
Keyword(s):  
Sustainable Development ◽  
Loss Rate ◽  
Rapid Development ◽  
Employment Opportunities ◽  
The Sustainable Development ◽  
High Loss ◽  
Hotel Employees ◽  
The Status ◽  
Face Threat ◽  
High Loss Rate

Hotels have offered a large number of employment opportunities for society as one of rapid development industries in our country. Whereas hotels face threat from the high loss rate of personnel' demission that even exceeds expected numerical value,as a result,loss directly influences the sustainable development of enterprises. This paper describes the status and characteristic of loss of hotels employees according to the investigation datum of personnel' demission interview in one hotel of Shenzhen,and dissects the main reason why employees leave their posts by adopting Maslow’s demand level theory.

scholarly journals Why unprecedented ozone loss in the Arctic in 2011? Is it related to climate change?

2013 ◽  
Vol 13 (10) ◽  
pp. 5299-5308 ◽  
Author(s):  
J.-P. Pommereau ◽  
F. Goutail ◽  
F. Lefèvre ◽  
A. Pazmino ◽  
C. Adams ◽  
...  
Keyword(s):  
Climate Change ◽  
Total Ozone ◽  
Loss Rate ◽  
The Arctic ◽  
Vortex Strength ◽  
High Loss ◽  
Ozone Loss ◽  
The Antarctic ◽  
High Loss Rate ◽  
Daily Total

Abstract. An unprecedented ozone loss occurred in the Arctic in spring 2011. The details of the event are revisited from the twice-daily total ozone and NO2 column measurements of the eight SAOZ/NDACC (Système d'Analyse par Observation Zénithale/Network for Detection of Atmospheric Composition Changes) stations in the Arctic. It is shown that the total ozone depletion in the polar vortex reached 38% (approx. 170 DU) by the end of March, which is larger than the 30% of the previous record in 1996. Aside from the long extension of the cold stratospheric NAT PSC period, the amplitude of the event is shown to be resulting from a record daily total ozone loss rate of 0.7% d−1 after mid-February, never seen before in the Arctic but similar to that observed in the Antarctic over the last 20 yr. This high loss rate is attributed to the absence of NOx in the vortex until the final warming, in contrast to all previous winters where, as shown by the early increase of NO2 diurnal increase, partial renoxification occurs by import of NOx or HNO3 from the outside after minor warming episodes, leading to partial chlorine deactivation. The cause of the absence of renoxification and thus of high loss rate, is attributed to a vortex strength similar to that of the Antarctic but never seen before in the Arctic. The total ozone reduction on 20 March was identical to that of the 2002 Antarctic winter, which ended around 20 September, and a 15-day extension of the cold period would have been enough to reach the mean yearly amplitude of the Antarctic ozone hole. However there is no sign of trend since 1994, either in PSC (polar stratospheric cloud) volume (volume of air cold enough to allow formation of PSCs), early winter denitrification, late vortex renoxification, and vortex strength or in total ozone loss. The unprecedented large Arctic ozone loss in 2011 appears to result from an extreme meteorological event and there is no indication of possible strengthening related to climate change.

Alaskan King Crab Boat Casualties

1978 ◽  
Vol 15 (01) ◽  
pp. 75-83
Author(s):  
Richard Lee Storch
Keyword(s):  
Stability Analysis ◽  
Loss Rate ◽  
King Crab ◽  
High Loss ◽  
General Overview ◽  
Insight Into ◽  
High Loss Rate

A casualty review of the Alaskan king crab fleet is used to provide insight into the causes of the high loss rate experienced by these boats. The casualty data include a general overview and more detailed discussion of 13 specific cases. Based on the casualty analysis, recommendations are made concerning vessel arrangements, stability analysis and vessel operations.

scholarly journals Reduced Postcapping Period in Honey Bees Surviving Varroa destructor by Means of Natural Selection

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 149 ◽  
Author(s):  
Melissa Oddie ◽  
Bjørn Dahle ◽  
Peter Neumann
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Common Garden ◽  
Colony Losses ◽  
Susceptible Population ◽  
Key Factor ◽  
Worker Brood ◽  
Colony Survival

The ectoparasitic mite Varroa destructor is a key factor for colony losses in European honey bee subspecies (Apis mellifera), but it is also known that some host populations have adapted to the mite by means of natural selection. The role of a shorter host brood postcapping period in reducing mite reproductive success has been investigated in other surviving subspecies, however its role in the adaptation of European honey bee populations has not been addressed. Here, we use a common garden approach to compare the length of the worker brood postcapping period in a Norwegian surviving honey bee population with the postcapping period of a local susceptible population. The data show a significantly shorter postcapping period in the surviving population for ~10% of the brood. Since even small differences in postcapping period can significantly reduce mite reproductive success, this mechanism may well contribute to natural colony survival. It appears most likely that several mechanisms acting together produce the full mite-surviving colony phenotype.

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