Fumigant toxicity of eleven Chinese herbal essential oils against an ectoparasitic mite (Varroa destructor) of the honey bee (Apis mellifera)

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.

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

Insects ◽

10.3390/insects12030216 ◽

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.

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

BMC Genomics ◽

10.1186/1471-2164-11-602 ◽

2010 ◽

Vol 11 (1) ◽

Cited By ~ 89

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

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Laboratory cage studies on the efficacy of some medicinal plant essential oils for controlling varroosis in Apis mellifera (Hym.: Apidae)

Systematic and Applied Acarology ◽

10.11158/saa.21.12.9 ◽

2016 ◽

Vol 21 (10) ◽

pp. 1681

Author(s):

Vahid Ghasemi ◽

Saeid Moharramipour ◽

Gholam Hossein Tahmasbi

Keyword(s):

Apis Mellifera ◽

Essential Oils ◽

Honey Bee ◽

Exposure Time ◽

Chemical Constituents ◽

Integrated Control ◽

Eucalyptus Camaldulensis ◽

Safe Alternative ◽

Plant Essential Oils ◽

Mite Mortality

Varroosis is a disease of Apis mellifera L. caused by the mite Varroa destructor Anderson and Trueman. Essential oils and their chemical constituents offer a safe alternative to synthetic acaricides for the control of this mite in bee hives. The present study was conducted to evaluate anti-parasitic activity of essential oils from Thymus kotschyanus Bioss & Hohen., Mentha longifolia L., Eucalyptus camaldulensis Dehnh., and Ferula gummosa L. at concentrations of 1, 2.5, 4, and 5.5 µl/l air for 5 and 10 h. Findings indicated that mite mortality increased as oils concentration and exposure time increased. T. kotschyanus oil at 5.5 µl/l air caused a mite mortality rate of 54.4% and 84.43% after 5 and 10 h fumigation, respectively. At the same concentration and exposure time, the honey bee mortality was 0% and 7.2%, respectively. Application of M. longifolia and E. camaldulensis oils at 5.5 µl/l air resulted in 65.53% and 71.06% mortality in Varroa mites and 10.13% and 12% mortality in honey bees after 10 h exposure. Despite moderate acaricidal activity of F. gummosa oil against Varroa mite (49.69%), it was highly toxic to honey bee (30%). Also, GC/MS analysis of the oils showed that carvacrol (47.99%) and thymol (30.61%) in T. kotschyanus oil, piperitenone (36.86%), piperitenone oxide (27.53%),Cispiperitone epoxide (22.21%), and pulegone (8.38%) in M. longifoliaoil, 1,8-cineol (74.7%) and α-pinene (8.35%) in E. camaldulensis oil, and β-pinene (87.29%) in F. gummosa oil were the main chemical constituents. Collectively, our results led to a conclusion that T. kotschyanus, M. longifolia, and E. camaldulensis oils have enough potential to play an important role in integrated control programs of varroosis in apiaries.

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

Pathogens ◽

10.3390/pathogens10091182 ◽

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.

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

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/75/1651 ◽

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).

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