scholarly journals A Case Report of Chronic Stress in Honey Bee Colonies Induced by Pathogens and Acaricide Residues

Author(s):  
Elena Alonso-Prados ◽  
Amelia-Virginia González-Porto ◽  
José Luis Bernal ◽  
José Bernal ◽  
Raquel Martín-Hernández ◽  
...  

In this Case Report we analyze the possible causes of the poor health status of a professional Apis mellifera iberiensis apiary located in Gajanejos (Guadalajara, Spain). Several factors that potentially favor colony collapse were identified, including Nosema ceranae infection, alone or in combination with other factors (eg, BQCV and DWV infection), and the accumulation of acaricides commonly used to control Varroa destructor in the beebread (coumaphos and tau-fluvalinate). Based on the levels of residues, the average toxic unit estimated for the apiary, suggests a possible increase in vulnerability to infection by N. ceranae due to the presence of high levels of acaricides. These data highlight the importance of evaluating these factors in future monitoring programs, as well as the need to adopt adequate preventive measures as part of national and international welfare programs aimed at guaranteeing the health and fitness of bees.

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 955
Author(s):  
Elena Alonso-Prados ◽  
Amelia-Virginia González-Porto ◽  
José Luis Bernal ◽  
José Bernal ◽  
Raquel Martín-Hernández ◽  
...  

In this case report, we analyze the possible causes of the poor health status of a professional Apis mellifera iberiensis apiary located in Gajanejos (Guadalajara, Spain). Several factors that potentially favor colony collapse were identified, including Nosema ceranae infection, alone or in combination with other factors (e.g., BQCV and DWV infection), and the accumulation of acaricides commonly used to control Varroa destructor in the beebread (coumaphos and tau-fluvalinate). Based on the levels of residues, the average toxic unit estimated for the apiary suggests a possible increase in vulnerability to infection by N. ceranae due to the presence of high levels of acaricides and the unusual climatic conditions of the year of the collapse event. These data highlight the importance of evaluating these factors in future monitoring programs, as well as the need to adopt adequate preventive measures as part of national and international welfare programs aimed at guaranteeing the health and fitness of bees.


2018 ◽  
pp. 83-87
Author(s):  
Marianna Takács ◽  
János Oláh

An apiary trial was conducted in 2016 August to October in Szabolcs-Szatmár-Bereg County, Nyírmada to evaluate the influence of queen’s age on the Varroa destructor-burden in the treatment colonies. Sixty colonies of bees belonging to the subspecies Apis mellifera carnica pannonica in Hunor loading hives (with 10 frames in the brood chamber/deep super) were used. The colonies were treated with amitraz and the organophosphate pesticide coumaphos active ingredients. The amitraz treatment includes 6 weeks. The coumaphos treatment with Destructor 3.2% can be used for both diagnosis and treatment of Varroasis. For diagnosis, one treatment is sufficient. For control, two treatments at an interval of seven days are required. The colonies were grouped by the age of the queen: 20 colonies with one-year-old, 20 colonies with two-year-old and 20 colonies with three-year-old queen. The mite mortality of different groups was compared. The number of fallen mites was counted at the white bottom boards. The examination of spring growth of honey bee colonies has become necessary due to the judgement of efficiency of closing treatment. The data was recorded seven times between 16th March 2017 and 19th May 2017. Data on fallen mites were subjected to one-way analysis of variance (ANOVA) and Post-Hoc Tukey-test. Statistical analysis was performed using the software of IBM SPSS (version 21.). During the first two weeks after treatments, the number of fallen mites was significantly higher in the older queen’s colonies (Year 2014). The total mite mortality after amitraz treatment in the younger queen’s colonies was lower (P<0.05) compared to the three-year-old queen’s colonies. According to Takács and Oláh (2016) although the mitemortality tendency, after the coumaphos (closing) treatment in colonies which have Year 2014 queen showed the highest rate, considering the mite-burden the colonies belongs to the average infected category. The colonial maintenance ability of three-year-old queen cannot be judged based on the influencing effect on the mite-burden. The importance of the replacement of the queen was judged by the combined effect of several factors. During the spring-growth study (16th March–19th May) was experienced in the three-year-old queen’s colonies the number of brood frames significantly lower compared to the one- and two-year-old queen’s colonies. In the study of 17th April and 19th May each of the three queen-year-groups were varied. Therefore in the beekeeping season at different times were determined the colonial maintenance ability of queens by more factors: efficiency of closing treatment in early spring, the spring-growth of bee colonies, the time of population shift (in current study, this time was identical in each queen-year), honey production (from black locust).


Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 243 ◽  
Author(s):  
Aleš Gregorc ◽  
Blair Sampson

Determining varroa mite infestation levels in honey bee colonies and the proper method and time to perform a diagnosis are important for efficient mite control. Performing a powdered sugar shake or counting mites that drop from combs and bees onto a hive bottom board are two reliable methods for sampling varroa mite to evaluate the efficacy of an acaricide treatment. This overview summarizes studies that examine the efficacy of organic acids and essential oils, mite monitoring, and brood interruption for integrated varroa mite control in organic beekeeping.


2011 ◽  
Vol 80 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Maja Ivana Smodiš Škerl ◽  
Mitja Nakrst ◽  
Lucija Žvokelj ◽  
Aleš Gregorc

During 2007 and 2008, natural mite mortality was recorded in honey bee colonies. These colonies were then treated with various acaricides against Varroa destructor and acaricide efficacies were evaluated. In 2007, experimental colonies were treated with flumethrin and/or oxalic acid and in 2008 the same colonies were treated with flumethrin, oxalic acid or amitraz. The efficacy of flumethrin in 2007 averaged 73.62% compared to 70.12% for three oxalic acid treatments. In 2008, a reduction of 12.52% in mite numbers was found 4 weeks after flumethrin application, while 4 oxalic acid applications produced significantly higher (P < 0.05) mite mortality, an average of 24.13%. Four consecutive amitraz fumigations produced a 93.82% reduction on average in final mite numbers and thus ensure normal colony development and overwintering. The study is important in order to demonstrate that synthetic acaricides should be constantly re-evaluated and the use of flumethrin at low efficacies need to be superseded by appropriate organic treatments to increase the efficacy of mite control in highly-infested colonies during the period of brood rearing.


Apidologie ◽  
2017 ◽  
Vol 48 (6) ◽  
pp. 821-832 ◽  
Author(s):  
Aleš Gregorc ◽  
Mohamed Alburaki ◽  
Chris Werle ◽  
Patricia R. Knight ◽  
John Adamczyk

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 969
Author(s):  
Isobel Grindrod ◽  
Jessica L. Kevill ◽  
Ethel M. Villalobos ◽  
Declan C. Schroeder ◽  
Stephen John Martin

The combination of Deformed wing virus (DWV) and Varroa destructor is arguably one of the greatest threats currently facing western honey bees, Apis mellifera. Varroa’s association with DWV has decreased viral diversity and increased loads of DWV within honey bee populations. Nowhere has this been better studied than in Hawaii, where the arrival of Varroa progressively led to the dominance of the single master variant (DWV-A) on both mite-infested Hawaiian Islands of Oahu and Big Island. Now, exactly 10 years following the original study, we find that the DWV population has changed once again, with variants containing the RdRp coding sequence pertaining to the master variant B beginning to co-dominate alongside variants with the DWV-A RdRp sequence on the mite-infested islands of Oahu and Big Island. In speculation, based on other studies, it appears this could represent a stage in the journey towards the complete dominance of DWV-B, a variant that appears better adapted to be transmitted within honey bee colonies.


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