scholarly journals A Meta-Analysis Shows That Screen Bottom Boards Can Significantly Reduce Varroa destructor Population

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 624
Author(s):  
Fang Liu ◽  
Xinjian Xu ◽  
Yuan Zhang ◽  
Hongxia Zhao ◽  
Zachary Y. Huang
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Negative Impact ◽  
Meta Analysis ◽  
Small Sample ◽  
Effect Sizes ◽  
Negative Results ◽  
Mite Control ◽  
Small Sample Sizes

Varroa destructor is by far the most serious threat to the western honey bee, Apis mellifera. A screen bottom board, a cultural method for mite control, is a modified bottom board with a screen that allows mites to fall onto a sticky board, or the grass or soil below the screen. Whether or not a screen bottom board can reduce varroa significantly has been controversial. Most studies show a trend of lower varroa populations in colonies with these boards, but the results are usually not statistically significant. To understand whether the negative results have been due to small sample sizes, or because the board is actually ineffective, we conducted a meta-analysis with seven published studies with a total of 145 colonies. Meta-analysis showed that the confidence intervals of the combined effect sizes were negative with a Hedges’ g of −1.09 (SE 0.39, 95% CI −2.0 to −0.19, p < 0.01), which suggests that the varroa population in colonies with screen bottom boards is significantly lower compared to those with traditional wooden floors. We thus conclude that the screen bottom board does have a significantly negative impact on the varroa population and can be part of tool kits for mite control.

scholarly journals Diagnosis of Varroa Mite (Varroa destructor) and Sustainable Control in Honey Bee (Apis mellifera) Colonies—A Review

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 243 ◽  
Author(s):  
Aleš Gregorc ◽  
Blair Sampson
Keyword(s):  
Apis Mellifera ◽  
Organic Acids ◽  
Essential Oils ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Mite Infestation ◽  
Varroa Mite ◽  
Mite Control ◽  
Bee Colonies ◽  
Reliable Methods

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.

Unsuccessful Treatments of “Writer's Block”: A Meta-Analysis

2014 ◽  
Vol 115 (1) ◽  
pp. 276-278 ◽  
Author(s):  
Derrick C. McLean ◽  
Benjamin R. Thomas
Keyword(s):  
Meta Analysis ◽  
Small Sample ◽  
The Body ◽  
Effect Sizes ◽  
Sample Sizes ◽  
Writer's Block ◽  
Unsuccessful Treatment ◽  
Group Treatments ◽  
Writer’S Block ◽  
Small Sample Sizes

A wide literature of the unsuccessful treatment of writer's block has emerged since the early 1970's. Findings within this literature seem to confer generalizability of this procedure; however, small sample sizes may limit this interpretation. This meta-analysis independently analyzed effect sizes for “self-treatments” and “group-treatments” using number of words in the body of the publication as indication of a failure to treat writer's block. Results of the reported findings suggest that group-treatments tend to be slightly more unsuccessful than self-treatments.

scholarly journals The acaricidal effect of flumethrin, oxalic acid and amitraz against Varroa destructor in honey bee (Apis mellifera carnica) colonies

2011 ◽  
Vol 80 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Maja Ivana Smodiš Škerl ◽  
Mitja Nakrst ◽  
Lucija Žvokelj ◽  
Aleš Gregorc
Keyword(s):  
Apis Mellifera ◽  
Oxalic Acid ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Colony Development ◽  
Apis Mellifera Carnica ◽  
Brood Rearing ◽  
Mite Control ◽  
Bee Colonies ◽  
Mite Mortality

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.

scholarly journals Exploring Two Honey Bee Traits for Improving Resistance Against Varroa destructor: Development and Genetic Evaluation

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 216
Author(s):  
Matthieu Guichard ◽  
Benoît Droz ◽  
Evert W. Brascamp ◽  
Adrien von Virag ◽  
Markus Neuditschko ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Field Trial ◽  
Genetic Evaluation ◽  
Phenotypic Correlation ◽  
Apis Mellifera Mellifera ◽  
Novel Traits ◽  
Resistance Traits

For the development of novel selection traits in honey bees, applicability under field conditions is crucial. We thus evaluated two novel traits intended to provide resistance against the ectoparasitic mite Varroa destructor and to allow for their straightforward implementation in honey bee selection. These traits are new field estimates of already-described colony traits: brood recapping rate (‘Recapping’) and solidness (‘Solidness’). ‘Recapping’ refers to a specific worker characteristic wherein they reseal a capped and partly opened cell containing a pupa, whilst ‘Solidness’ assesses the percentage of capped brood in a predefined area. According to the literature and beekeepers’ experiences, a higher recapping rate and higher solidness could be related to resistance to V. destructor. During a four-year field trial in Switzerland, the two resistance traits were assessed in a total of 121 colonies of Apis mellifera mellifera. We estimated the repeatability and the heritability of the two traits and determined their phenotypic correlations with commonly applied selection traits, including other putative resistance traits. Both traits showed low repeatability between different measurements within each year. ‘Recapping’ had a low heritability (h2 = 0.04 to 0.05, depending on the selected model) and a negative phenotypic correlation to non-removal of pin-killed brood (r = −0.23). The heritability of ‘Solidness’ was moderate (h2 = 0.24 to 0.25) and did not significantly correlate with resistance traits. The two traits did not show an association with V. destructor infestation levels. Further research is needed to confirm the results, as only a small number of colonies was evaluated.

scholarly journals Genomic survey of the ectoparasitic mite Varroa destructor, a major pest of the honey bee Apis mellifera

BMC Genomics ◽  
2010 ◽  
Vol 11 (1) ◽  
Author(s):  
R Scott Cornman ◽  
Michael C Schatz ◽  
J Spencer Johnston ◽  
Yan-Ping Chen ◽  
Jeff Pettis ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Major Pest

Clinical outcomes of cancer patients with COVID-19: A systematic review and meta-analysis.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18600-e18600
Author(s):  
Maryam Alasfour ◽  
Salman Alawadi ◽  
Malak AlMojel ◽  
Philippos Apolinario Costa ◽  
Priscila Barreto Coelho ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Cancer Patients ◽  
Clinical Outcomes ◽  
Meta Analysis ◽  
Small Sample ◽  
Prediction Intervals ◽  
Invasive Ventilation ◽  
Newcastle Ottawa Scale ◽  
Small Sample Sizes ◽  
Meta Analyses

e18600 Background: Patients with coronavirus disease 2019 (COVID-19) and cancer have worse clinical outcomes compared to those without cancer. Primary studies have examined this population, but most had small sample sizes and conflicting results. Prior meta-analyses exclude most US and European data or only examine mortality. The present meta-analysis evaluates the prevalence of several clinical outcomes in cancer patients with COVID-19, including new emerging data from Europe and the US. Methods: A systematic search of PubMED, medRxiv, JMIR and Embase by two independent investigators included peer-reviewed papers and preprints up to July 8, 2020. The primary outcome was mortality. Other outcomes were ICU and non-ICU admission, mild, moderate and severe complications, ARDS, invasive ventilation, stable, and clinically improved rates. Study quality was assessed through the Newcastle–Ottawa scale. Random effects model was used to derive prevalence rates, their 95% confidence intervals (CI) and 95% prediction intervals (PI). Results: Thirty-four studies (N = 4,371) were included in the analysis. The mortality prevalence rate was 25.2% (95% CI: 21.1–29.7; 95% PI: 9.8-51.1; I 2 = 85.4), with 11.9% ICU admissions (95% CI: 9.2-15.4; 95% PI: 4.3-28.9; I 2= 77.8) and 25.2% clinically stable (95% CI: 21.1-29.7; 95% PI: 9.8-51.1; I 2 = 85.4). Furthermore, 42.5% developed severe complications (95% CI: 30.4-55.7; 95% PI: 8.2-85.9; I 2 = 94.3), with 22.7% developing ARDS (95% CI: 15.4-32.2; 95% PI: 5.8-58.6; I 2 = 82.4), and 11.3% needing invasive ventilation (95% CI: 6.7-18.4; 95% PI: 2.3-41.1; I 2 = 79.8). Post-follow up, 49% clinically improved (95% CI: 35.6-62.6; 95% PI: 9.8-89.4; I 2 = 92.5). All outcomes had large I 2 , suggesting high levels of heterogeneity among studies, and wide PIs indicating high variability within outcomes. Despite this variability, the mortality rate in cancer patients with COVID-19, even at the lower end of the PI (9.8%), is higher than the 2% mortality rate of the non-cancer with COVID-19 population, but not as high as what other meta-analyses conclude, which is around 25%. Conclusions: Patients with cancer who develop COVID-19 have a higher probability of mortality compared to the general population with COVID-19, but possibly not as high as previous studies have shown. A large proportion of them developed severe complications, but a larger proportion recovered. Prevalence of mortality and other outcomes published in prior meta-analyses did not report prediction intervals, which compromises the clinical utilization of such results.

scholarly journals In Vitro Evaluation of Acute Toxicity of Five Citrus spp. Essential Oils towards the Parasitic Mite Varroa destructor

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1182
Author(s):  
Roberto Bava ◽  
Fabio Castagna ◽  
Cristian Piras ◽  
Ernesto Palma ◽  
Giuseppe Cringoli ◽  
...  
Keyword(s):  
Essential Oils ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Negative Impact ◽  
Positive Control ◽  
Citrus Limon ◽  
Citrus Paradisi ◽  
Bee Health ◽  
Citrus Spp

Varroa destructor is the most important ectoparasitic mite of honey bees that has a negative impact on bee health and honey production. The control programs are mainly based on the use of synthetic acaricides that are often administered indiscriminately. All this has led to drug resistance that now represent a great concern for honey bee farming. The research for alternative products/methods for mites’ control is now mandatory. The aim of this study was to test whether Citrus spp. essential oils could diminish the growth of the V. destructor mite. In Calabria (southern Italy), plants of the Citrus genus are very common and grow both spontaneously and cultured. The essential oils used in this study were extracted from bergamot (Citrus bergamia), grapefruit (Citrus paradisi), lemon (Citrus limon), orange (Citrus sinensis), and mandarin (Citrus reticulata) by hydrodistillation. Every EO was in vitro tested against V. destructor. Each experimental replicate was performed using 35 viable adult female mites (5 for each EO) collected the same day from the same apiary and included negative controls (5 individuals exposed to acetone only) and positive controls (5 individuals exposed to Amitraz diluted in acetone). The essential oils (Eos) were diluted (0.5 mg/mL, 1 mg/mL, and 2 mg/mL) in HPLC grade acetone to obtain the working solution to be tested (50 µL/tube). Mite mortality was manually assessed after 1 h exposure under controlled conditions. The essential oils that showed the best effectiveness at 0.5 mg/mL were bergamot, which neutralized (dead + inactivated) 80% (p ≤ 0.001) of the parasites; grapefruit, which neutralized 70% (p ≤ 0.001); and lemon, which neutralized 69% of them. Interestingly, the positive control (Amitraz) at the same concentration neutralized 60% of the parasites. These results demonstrate that Calabrian bergamot, grapefruit, and lemon Eos consistently reduced V. destructor viability and open the possibility for their utilization to control this parasite in honey bee farming.

scholarly journals The effect of the queen's age on the Varroa mite (Varroa destructor) burden of honey bee (Apis mellifera L.) colonies

2018 ◽  
pp. 83-87
Author(s):  
Marianna Takács ◽  
János Oláh
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Early Spring ◽  
Brood Chamber ◽  
One Year ◽  
The One ◽  
Post Hoc ◽  
Bee Colonies ◽  
Mite Mortality

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).

scholarly journals Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Desiderato Annoscia ◽  
Gennaro Di Prisco ◽  
Andrea Becchimanzi ◽  
Emilio Caprio ◽  
Davide Frizzera ◽  
...  
Keyword(s):  
Immune Responses ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Negative Impact ◽  
Asymptomatic Infection ◽  
Varroa Mite ◽  
Deformed Wing Virus ◽  
Synergistic Interactions ◽  
Parasitic Mite

AbstractThe neonicotinoid Clothianidin has a negative impact on NF-κB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees.

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