scholarly journals To Treat or Not to Treat Bees? Handy VarLoad: A Predictive Model for Varroa destructor Load

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Hélène Dechatre ◽  
Lucie Michel ◽  
Samuel Soubeyrand ◽  
Alban Maisonnasse ◽  
Pierre Moreau ◽  
...  
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Early Spring ◽  
Brood Cell ◽  
Regular Treatment ◽  
Cell Numbers ◽  
Risks And Benefits ◽  
Initial Load ◽  
Colony Performance ◽  
Bee Colonies

The parasitic Varroa destructor is considered a major pathogenic threat to honey bees and to beekeeping. Without regular treatment against this mite, honey bee colonies can collapse within a 2–3-year period in temperate climates. Beyond this dramatic scenario, Varroa induces reductions in colony performance, which can have significant economic impacts for beekeepers. Unfortunately, until now, it has not been possible to predict the summer Varroa population size from its initial load in early spring. Here, we present models that use the Varroa load observed in the spring to predict the Varroa load one or three months later by using easily and quickly measurable data: phoretic Varroa load and capped brood cell numbers. Built on 1030 commercial colonies located in three regions in the south of France and sampled over a three-year period, these predictive models are tools designed to help professional beekeepers’ decision making regarding treatments against Varroa. Using these models, beekeepers will either be able to evaluate the risks and benefits of treating against Varroa or to anticipate the reduction in colony performance due to the mite during the beekeeping season.

scholarly journals Fecundity and trapping of Varroa destructor (Mesostigmata: Varroidae) in Greek drone brood of Apis melifera (Hymenoptera: Apididae)

2012 ◽  
Vol 44 (3) ◽  
pp. 18 ◽  
Author(s):  
Petros T. Damos
Keyword(s):  
Reproductive Performance ◽  
Varroa Destructor ◽  
Early Spring ◽  
Early Summer ◽  
Brood Cell ◽  
Northern Greece ◽  
Drone Brood ◽  
Varroa Mites ◽  
Successive Generations ◽  
Bee Colonies

This study estimates the parasitization levels and fecundity of the ectoparasitic mite <em>Varroa destructor</em> Oudemans in drone brood of bee colonies located in Northern Greece. Based on successive observations in spring and early summer, the study also examines whether early entrapment of mites into the drone brood cell decreases the mite population levels in the succeeding generation. Varroa populations in drone brood were extremely high (approx. 40%) in early spring, although numbers dropped significantly (approx. 20%) after the entrapment and removal of mites into the drone brood (t=4.14518, P=0.0136, Mann-Whitney: P=0.005). In most cases, more than half of the inspected cells were occupied with two or more parental mites. No significant differences were found in the reproductive performance of the Varroa mites between the two successive generations in spring and early summer (t=-0.607, P=0.554, Mann-Whitney: P=0.128). The reproductive performance of <em>V. destructor</em> ranged from 1.5-3 progeny per female individual (m1:1.673, SE=0.09 and m2:2.02, SE: 0.44 for the first and second generations, respectively). A positive and significant correlation was observed between the drone and the mite populations (y=0.830+1.153x, F=8.851, P=0.41, R<sup>2</sup>:0.689 and y=0.319+0.968x, F=45.276, R<sup>2</sup>: 0,938, P=0.07 for the first and second mite generations, respectively). There were no significant differences in the number of infested and non-infested cells during the first observations (m1: 105.2, SE: 25.0, m2: 170.0 SE: 40.0, t=-1.38, P=0.203, Mann-Whitney: n1:81.0, n2:142.5, P=0.0656). On the contrary, during the second observations the number of infested cells was significantly lower (m1: 27.6, SE:8.1, m2:262.8, SE:69.0, t=-3.39, P=0.027, Mann-Whitney: P=0.012, n1:20, n2:340).

scholarly journals Winter Survival of Individual Honey Bees and Honey Bee Colonies Depends on Level of Varroa destructor Infestation

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e36285 ◽  
Author(s):  
Coby van Dooremalen ◽  
Lonne Gerritsen ◽  
Bram Cornelissen ◽  
Jozef J. M. van der Steen ◽  
Frank van Langevelde ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Winter Survival ◽  
Bee Colonies

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 Ten Years of Deformed Wing Virus (DWV) in Hawaiian Honey Bees (Apis mellifera), the Dominant DWV-A Variant Is Potentially Being Replaced by Variants with a DWV-B Coding Sequence

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 969
Author(s):  
Isobel Grindrod ◽  
Jessica L. Kevill ◽  
Ethel M. Villalobos ◽  
Declan C. Schroeder ◽  
Stephen John Martin
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Original Study ◽  
Viral Diversity ◽  
Deformed Wing Virus ◽  
Complete Dominance ◽  
Coding Sequence ◽  
Bee Colonies

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.

scholarly journals Safety assessment of sugar dusting treatments by analysis of hygienic behavior in honey bee colonies

2011 ◽  
Vol 63 (4) ◽  
pp. 1199-1207 ◽  
Author(s):  
Jevrosima Stevanovic ◽  
Z. Stanimirovic ◽  
Nada Lakic ◽  
Nevenka Aleksic ◽  
P. Simeunovic ◽  
...  
Keyword(s):  
Pest Management ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Safety Assessment ◽  
Defense Mechanism ◽  
Management Strategies ◽  
Hygienic Behavior ◽  
Natural Defense ◽  
Bee Colonies

The hygienic behavior in honey bees is a dominant natural defense mechanism against brood diseases. In this study, the influence of sugar dusting treatments on hygienic behavior was evaluated in 44 strong honey bee colonies. Three doses of pulverized sugar, 20, 30 and 40 g, each applied at three-, seven- and fourteen-day intervals were tested. The percentage of cleaned cells (PCC) in the total number of those with pin-killed brood served as a measure of the hygienic potential. The effect was dependent on the frequency of treatments: all doses applied every third and seventh day significantly (p<0.001) decreased the PCC in comparison with the untreated control colonies. Nevertheless, sugar did not threaten the hygienic potential, as PPC values remained above 94% following all treatments. Thus, it can be concluded that the tested sugar treatments are safe and can be justifiably implemented into integrated pest management strategies to control Varroa destructor.

Honey production of honey bee (Hymenoptera: Apidae) colonies with high and low Varroa destructor (Acari: Varroidae) infestation rates in eastern Canada

2013 ◽  
Vol 146 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Berna Emsen ◽  
Ernesto Guzman-Novoa ◽  
Paul G. Kelly
Keyword(s):  
Population Growth ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Early Spring ◽  
Mite Infestation ◽  
Infestation Level ◽  
Varroa Mite ◽  
Eastern Canada ◽  
Honey Production ◽  
Bee Colonies

AbstractThe objective of this study was to compare the honey yields of groups of honey bee (Hymenoptera: Apidae) colonies with high and low infestation rates of the mite Varroa destructor Anderson and Trueman (Acari: Varroidae). More than 150 colonies were screened for mite fall in early spring and again 16 weeks later. The 10 colonies with the lowest rates (L) and the 10 colonies with the highest rates (H) of mite population growth were selected. These 20 colonies were evaluated for mite infestation in adult bees and honey production. Adult bee infestation in the colonies of the H group was significantly higher than in the colonies of the L group. Additionally, H and L colonies differed significantly for honey production. L colonies produced 28.91 ± 2.34 kg of honey per hive versus 18.49 ± 0.77 kg for the group of H colonies. Furthermore, the mite infestation level of colonies measured as mite fall or as number of mites per 100 bees, was significantly correlated with honey production (r = −0.62, P < 0.05 and r = −0.76, P < 0.01, respectively). These results indicate that varroa mite populations significantly reduce honey yields in honey bee colonies in eastern Canada.

scholarly journals Effectiveness of Oxalis bee and Ecostop for prophylaxis and control of varroosis in honey bees (Apis mellifera L.)

2018 ◽  
Vol 10 (4) ◽  
pp. 344-348
Author(s):  
I. Zhelyazkova ◽  
S. Lazarov
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Prevention And Control ◽  
Feed Additive ◽  
Peppermint Oil ◽  
Bee Plant ◽  
Experimental Training ◽  
And Control ◽  
Bee Colonies

Abstract. The objective of the present study is to determine the effectiveness of Ecostop (plates) and Oxalis Bee - plant-based products for the prevention and control of varroosis in bees (Apis mellifera L.).The study was conducted at the end of the 2017 Beekeeping Season of the Beekeeping Experimental Training Center at the Faculty of Agriculture, Trakia University, Stara Zagora. Two products were used: Ecostop containing peppermint oil (2 ml/plate) and timol (5 g/plate), and Oxalis Bee - zootechnical feed additive for bees, including plant extracts, organic acids and invert solution from bio-sugar. The dosing of the products is in accordance with the instructions of the producers Primavet-Sofia Ltd., Bulgaria and the company Vechni pcheli Ltd., Bulgaria. The development and extensinvasion of bee colonies at the beginning and the end of the study and the effectiveness of the applied products were determined. It has been established that the development of bee colonies is normal for the end of the beekeeping season. The comparative analysis of the acaricidal effect of the test products against Varroa destructor shows 98.55±0.30% for Ecostop and 78.15±8.76% for Oxalis Bee. The reported difference in efficacy of both preparations is reliable at p≤0.05.

How to quantify Varroa destructor in honey bee (Apis mellifera L.) colonies

EDIS ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 8
Author(s):  
Cameron Jack ◽  
Nathan Sperry ◽  
Ashley N. Mortensen ◽  
Jamie Ellis
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Fact Sheet ◽  
Bee Colonies

The Varroa destructor mite, a devastating pest of western honey bees, can threaten a honey bee colony’s survival if it is left uncontrolled. This 8-page fact sheet written by Cameron Jack, Nathan Sperry, Ashley N. Mortensen, and Jamie Ellis and published by the UF/IFAS Entomology and Nematology Department explains how to monitor honey bee colonies to ensure that infestations of these destructive pests do not grow to dangerous levels.https://edis.ifas.ufl.edu/in1257

Timing of acaracide treatments for control of low-level populations of Varroa destructor (Acari: Varroidae) and implications for colony performance of honey bees

2003 ◽  
Vol 135 (5) ◽  
pp. 749-763 ◽  
Author(s):  
P. Gatien ◽  
R.W. Currie
Keyword(s):  
Formic Acid ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Brood Chamber ◽  
Low Level ◽  
Need For Treatment ◽  
Honey Production ◽  
Colony Performance ◽  
The Mean ◽  
Colony Survival

AbstractThe timing of acaracide treatments for control of low-level populations of Varroa destructor Anderson et Trueman has implications for colony performance of honey bees, Apis mellifera L. (Hymenoptera: Apidae). Replicated colonies with low levels of V. destructor were left untreated, exposed to fluvalinate at each of two doses for 42 days, or exposed to three applications of formic acid, with the four treatments applied in either spring or fall. Varroa destructor densities were measured by alcohol wash and drop boards, and both gave similar estimates. Over the course of one season, the mean abundance of V. destructor increased from 0.002 to 0.11 mites per bee. Extended broodless periods during winter reduced the mean abundance of V. destructor by 28%, but mite mortality over winter was not high enough to prevent the need for treatment the following year. Apistan® was more effective than formic acid in both spring and fall treatments. Doses of one or two strips of Apistan® per colony were equally effective in spring or fall treatments. The mean abundance of V. destructor remained low throughout the season following spring treatment with either dose of Apistan®. Fall formic-acid treatments were more effective than spring treatments. Fluvalinate residues in samples of honey and wax collected from brood chambers and from honey supers were slightly higher in colonies treated with two strips of Apistan® than with one strip, but no detectible residue was found in extracted honey from 4500 commercial colonies treated in spring with Apistan® one strip per brood chamber for single or double storey hives. The levels of V. destructor in this study did not affect honey production or colony survival over winter.

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