scholarly journals Evaluating the Efficacy of 30 Different Essential Oils against Varroa destructor and Honey Bee Workers (Apis mellifera)

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1045
Author(s):  
Marian Hýbl ◽  
Andrea Bohatá ◽  
Iva Rádsetoulalová ◽  
Marek Kopecký ◽  
Irena Hoštičková ◽  
...  

Essential oils and their components are generally known for their acaricidal effects and are used as an alternative to control the population of the Varroa destructor instead of synthetic acaricides. However, for many essential oils, the exact acaricidal effect against Varroa mites, as well as the effect against honey bees, is not known. In this study, 30 different essential oils were screened by using a glass-vial residual bioassay. Essential oils showing varroacidal efficacy > 70% were tested by the complete exposure assay. A total of five bees and five mites were placed in the Petri dishes in five replications for each concentration of essential oil. Mite and bee mortality rates were assessed after 4, 24, 48, and 72 h. The LC50 values and selectivity ratio (SR) were calculated. For essential oils with the best selectivity ratio, their main components were detected and quantified by GC-MS/MS. The results suggest that the most suitable oils are peppermint and manuka (SR > 9), followed by oregano, litsea (SR > 5), carrot, and cinnamon (SR > 4). Additionally, these oils showed a trend of the increased value of selective ratio over time. All these oils seem to be better than thymol (SR < 3.2), which is commonly used in beekeeping practice. However, the possible use of these essential oils has yet to be verified in beekeeping practice.


2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Qodratollah Sabahi ◽  
Mollah Md. Hamiduzzaman ◽  
Juan S. Barajas-Pérez ◽  
Jose M. Tapia-Gonzalez ◽  
Ernesto Guzman-Novoa

This study examined the toxicity of anethole and that of the essential oils of lemongrass (Cymbopogon citratus) and sweet marigold (Tagetes lucida) to the mite Varroa destructor and to honey bee workers and larvae. Anethole was the most toxic compound to V. destructor (LC50: 304.9 μg/ml), whereas Tagetes oil was the least toxic (LC50: 1256.27 μg/ml). The most and least toxic compounds to worker bees were anethole and Tagetes oil with LD50s of 35942 and 85381 μg/ml, respectively. For larvae, Tagetes oil was the most toxic compound (LD50: 9580.7 μg/ml) and anethole the least toxic (LD50: 14518.0 μg/ml). Anethole and Cymbopogon oil had the highest selectivity ratios. The expression of AChE, a gene that regulates the production of acetyl cholinesterase, a detoxifying enzyme, was not altered in bees treated with the plant compounds at 48 h post-treatment. This study showed that anethole and Cymbopogon oil have potential for controlling Varroa mites and seem to be relatively safe for larvae and adult honey bees.



2008 ◽  
Vol 86 (9) ◽  
pp. 1059-1067 ◽  
Author(s):  
R. W. Currie ◽  
G. H. Tahmasbi

This study assessed how variation in temperature and humidity affect the costs and benefits of grooming as a defense against Varroa destructor Anderson and Trueman, 2000 in high-grooming and low-grooming groups of honey bee (Apis mellifera L., 1758) workers. Grooming was quantified as the proportion of mites falling to the bottom of cages containing worker bees or to the bottom of colonies of bees during winter. Cages of 100 mite-infested bees from each line of workers were assigned to environments with three treatment combinations of temperature (10, 25, and 34 °C) and humidity (low, medium, and high), and bee and mite mortality rates were quantified. The results showed relative effectiveness of high- and low-grooming groups being affected by the environment. Differences in grooming between lines were greatest at 25 °C and were slightly higher under conditions of low humidity than at higher levels. Mite mortality rates were greater in high-grooming groups of caged bees than in low-grooming bees held at 25 and 34 °C but were similar at 10 °C. During winter, colonies with high-grooming bees had higher daily mite mortality rates than unselected colonies. Bee mortality rates were greater in high-grooming lines than in low-grooming lines under low temperatures, indicating that there may be a biological cost associated with grooming behaviour at low temperature.



Biologija ◽  
2017 ◽  
Vol 63 (2) ◽  
Author(s):  
Ataollah Rahimi ◽  
Yaser Khoram Del ◽  
Farzad Moradpour

Chemical control of the Varroa mite (Varroa destructor), which is one of the most important pests of honey bees, is practiced on a worldwide scale. However, because of abundant use of different acaricides, the mites have become resistant to many of them. We chose to apply non-synthetic chemicals for control of Varroa mites by using thyme (Thymus caucasicus) ethanol extract on honey bees. In September-October 2013, we collected wild thyme growing in Kurdistan mountains, ground it, and its ethanol extract was made by using 95% ethylic alcohol. We used a randomized complete design with ten treatments of different concentrations of ethanol extract of thyme as a statistical model and one control with pure 95% ethanol with four replications. The interior temperature of the brood chamber was measured to be 30 ± 1°C, and the ambient temperature surrounding them was 33 ± 2°C. We sprayed the extracted thyme solution on honey bees and counted the number of dead mites by picking them out from the bottom board of each hive at every 12 h, 24 h, and 48 h intervals after spraying. The results showed that the use of the thyme extract influenced significantly the percentage of mortality of dead mites in the extract-sprayed treatment and the control treatment. The percentage of mortality of the honey bees in control hives and the honey bees treated by thyme ethanol extract did not have a significant difference. Results of our experiment using ethanol extract of thyme showed that its use in hives was safe without a high risk of mortality for honey bees.



2018 ◽  
Vol 19 (4) ◽  
pp. 954-958 ◽  
Author(s):  
Martin Buchegger ◽  
Ralph Buechler ◽  
Birgit Fuerst-Waltl ◽  
Marin Kovačić ◽  
Alfons Willam


2009 ◽  
Vol 48 (4) ◽  
pp. 256-262 ◽  
Author(s):  
Diana Sammataro ◽  
Jennifer Finley ◽  
Blaise LeBlanc ◽  
Gordon Wardell ◽  
Fabiana Ahumada-Segura ◽  
...  


Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 372 ◽  
Author(s):  
Wenfeng Li ◽  
Cheng Wang ◽  
Zachary Y. Huang ◽  
Yanping Chen ◽  
Richou Han

Honey bees play important roles in pollination for many crops and wild plants, but have been facing great threats posed by various pathogens and parasites. Among them, Varroa destructor, an obligate ectoparasite of honey bees, is considered the most damaging. Within the last century, V. destructor shifted from the original host, the Asian honey bee Apis cerana to the new host, the European honey bee A. mellifera. However, the reproduction of Varroa mites, especially of different haplotypes in the two hosts, is still largely unknown. In this study, we first investigated the existing Varroa haplotypes in local colonies in southern China, and then compared the reproduction of different haplotypes on the worker brood of both the original and new hosts by artificial inoculation. We confirmed that there are two haplotypes of V. destructor in southern China, one is the Korea haplotype and the other is the China haplotype, and the two types parasitized different honey bee species. Although Varroa females from A. mellifera (Korea haplotype) are able to reproduce on the worker brood of both honey bee species, they showed better reproductive performance in the new host A. mellifera with significantly higher fecundity (number of offspring per mother mite) and reproductive rate (number of adult daughters per mother mite), suggesting that this parasite gains higher fitness after host shift. The data further showed that a short stay of Varroa females inside the A. cerana worker cells decreased their fecundity and especially the reproductive rate in a time-dependent manner, suggesting that the A. cerana worker cells may inhibit Varroa reproduction. In contrast, Varroa mites derived from A. cerana colonies (China haplotype) were entirely sterile in A. mellifera worker cells during two sequential inoculations, while the control mites from A. mellifera colonies (Korea haplotype) reproduced normally. In addition, all the infertile mites were found to defecate on the abdomen of bee pupae. We have revealed that two haplotypes of V. destructor exhibit differential reproduction on the worker brood of the original and new host honey bees, providing novel insights into the diversity and complexity of the reproduction of V. destructor.



Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 679
Author(s):  
Gongwen Chen ◽  
Shuai Wang ◽  
Shuo Jia ◽  
Ye Feng ◽  
Fuliang Hu ◽  
...  

The ectoparasitic mite, Varroa destructor, feeds directly on honey bees and serves as a vector for transmitting viruses among them. The Varroa mite causes relatively little damage to its natural host, the Eastern honey bee (Apis cerana) but it is the most devastating pest for the Western honey bee (Apis mellifera). Using Illumina HiSeq sequencing technology, we conducted a metatranscriptome analysis of the microbial community associated with Varroa mites. This study led to the identification of a new Chinese strain of Varroa destructor virus-2 (VDV-2), which is a member of the Iflaviridae family and was previously reported to be specific to Varroa mites. A subsequent epidemiological investigation of Chinese strain of VDV-2 (VDV-2-China) showed that the virus was highly prevalent among Varroa populations and was not identified in any of the adult workers from both A. mellifera and A.cerana colonies distributed in six provinces in China, clearly indicating that VDV-2-China is predominantly a Varroa-adapted virus. While A. mellifera worker pupae exposed to less than two Varroa mites tested negative for VDV-2-China, VDV-2-China was detected in 12.5% of the A. mellifera worker pupae that were parasitized by more than 10 Varroa mites, bringing into play the possibility of a new scenario where VDV-2 could be transmitted to the honey bees during heavy Varroa infestations. Bioassay for the VDV-2-China infectivity showed that A. cerana was not a permissive host for VDV-2-China, yet A. mellifera could be a biological host that supports VDV-2-China’s replication. The different replication dynamics of the virus between the two host species reflect their variation in terms of susceptibility to the virus infection, posing a potential threat to the health of the Western honey bee. The information gained from this study contributes to the knowledge concerning genetic variabilities and evolutionary dynamics of Varroa-borne viruses, thereby enhancing our understanding of underlying molecular mechanisms governing honey bee Varroosis.



Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1032
Author(s):  
Ziyad Abdul Qadir ◽  
Atif Idrees ◽  
Rashid Mahmood ◽  
Ghulam Sarwar ◽  
Muhammad Abu Bakar ◽  
...  

Honey bees (Apis mellifera) are essential for their products—honey, royal jelly, pollen, propolis and beeswax. They are also indispensable because they support ecosystems with their pollination services. However, the production and functions of honey bees are hindered by the arthropod pest Varroa destructor, which attacks bees through its feeding activities. Efforts to control varroa mites have been made through the development of various synthetic pesticide groups, but have had limited success because the mites developed resistance and some of these pesticides are harmful to bees. Branded pesticides are rarely used in Pakistan, as beekeepers utilize acaricides from unknown sources. There is a need to create awareness of available naturally occurring acaricides that may serve as an alternative to synthetic acaricides. Although some naturally occurring compounds are considered toxic to the environment, the soft acaricides oxalic acid, thymol, and formic acid 65% are usually safe for honey bee colonies and beekeepers, when handled appropriately. The current study investigated the effectiveness of formic acid (10, 15, and 20 mL/hive), oxalic acid (4.2, 3.2, and 2.1%/hive), and thymol (6, 4, and 2 g/hive) in controlling mite infestation. The results indicated that all treatments significantly reduced the mite population (p < 0.05). The average efficacies of oxalic acid at 3.2% (94.84% ± 0.34) and 4.2% (92.68% ± 0.37) were significantly higher than those of the other treatments. The lowest efficacy was recorded in formic acid 65% at 10 mL (54.13%). Overall, the results indicated that soft acaricides—such as oxalic acid at 3.2% and 4.2% concentrations—are very effective at controlling varroa mites and can be used in broodless conditions without side effects.



2020 ◽  
pp. 1-11
Author(s):  
Michael Light ◽  
Nicoletta Faraone ◽  
Dave Shutler ◽  
G. Christopher Cutler ◽  
N. Kirk Hillier

Abstract Essential oils produced by plants are a rich source of metabolites that can have toxic or behaviour-modifying effects on arthropods. Some essential oils have shown promise in management of the mite Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae), a parasite of western honey bees, Apis mellifera Linnaeus (Hymenoptera: Apidae). Essential oil and its components from common yarrow, Achillea millefolium Linnaeus (Asteraceae), are reported to have both insecticidal and repellent properties for other arthropod pests and may have activity against V. destructor. Here, we evaluate responses of V. destructor towards common yarrow essential oil using gas chromatography paired with electrotarsal detection. We identified 38 essential oil components that elicited electrophysiological responses from V. destructor. Components of common yarrow essential oil identified as electrophysiologically active in this study are reported elsewhere as active components of other management strategies for V. destructor infestations (e.g., thyme oil; Thymus sp. (Lamiaceae)). Pending behavioural assessment, the efficacy of common yarrow essential oil in honey bee colonies infested by V. destructor should be explored in field conditions.



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