Molecular Detection of Nosema spp. in Honey in Bulgaria

Environmental DNA (eDNA) analysis is related to screening genetic material of various organisms in environmental samples. Honey represents a natural source of exogenous DNA, which allows for the detection of different honey bee pathogens and parasites. In the present study, we extracted DNA from 20 honey samples from different regions in Bulgaria and tested for the presence of DNA of the ectoparasitic mite Varroa destructor, as well as Nosema apis and Nosema ceranae. Only Nosema ceranae was detected, showing up in 30% of all samples, which confirms the widespread prevalence of this pathogen. All positive samples were found in plain regions of the country, while this pathogen was not detected in mountainous parts. None of the samples gave positive amplifications for the Nosema apis and Varroa mite. The obtained results from this study confirm previous observations that eDNA contained in honey is a potent source for effective biomonitoring of actual diseases in the honey bee.

Diverse and rapidly evolving viral strategies modulate arthropod vector gene expression

Vector-borne viral diseases threaten human and wildlife worldwide. Vectors are often viewed as a passive syringe injecting the virus, however to survive, replicate and spread, viruses must manipulate vector biology. While most vector-borne viral research focuses on vectors transmitting a single virus, in reality vectors often carry diverse viruses. Yet how viruses affect the vectors remains poorly understood. Here we focused on the varroa mite, an emergent parasite that vectors over 20 honey bee viruses, and has been responsible for colony collapses worldwide, as well as changes in global viral populations. Co-evolution of the varroa and the viral community makes it possible to investigate whether viruses affect vector gene expression, and whether these interactions affect viral epidemiology. Using a large set of available varroa transcriptomes we identified how abundances of individual viruses affect the vector transcriptional network. Perhaps surprisingly, we found no evidence of competition between viruses, but rather that some virus abundances are positively correlated. Furthermore, we found a strong correlation between the extent to which a virus interacts with the vector gene expression and co-occurrence with other viruses, suggesting that interactions with the vector affect epidemiology. We experimentally validated this observation by silencing candidate genes using RNAi and found that reduction in varroa gene expression was accompanied by a change in viral load. Combined, the meta-transcriptomic analysis and experimental results shed light on the mechanism by which viruses interact with each other and with their vector to shape the disease course.

Unprecedented Density and Persistence of Feral Honey Bees in Urban Environments of a Large SE-European City (Belgrade, Serbia)

It is assumed that wild honey bees have become largely extinct across Europe since the 1980s, following the introduction of exotic ectoparasitic mite (Varroa) and the associated spillover of various pathogens. However, several recent studies reported on unmanaged colonies that survived the Varroa mite infestation. Herewith, we present another case of unmanaged, free-living population of honey bees in SE Europe, a rare case of feral bees inhabiting a large and highly populated urban area: Belgrade, the capital of Serbia. We compiled a massive data-set derived from opportunistic citizen science (>1300 records) during the 2011–2017 period and investigated whether these honey bee colonies and the high incidence of swarms could be a result of a stable, self-sustaining feral population (i.e., not of regular inflow of swarms escaping from local managed apiaries), and discussed various explanations for its existence. We also present the possibilities and challenges associated with the detection and effective monitoring of feral/wild honey bees in urban settings, and the role of citizen science in such endeavors. Our results will underpin ongoing initiatives to better understand and support naturally selected resistance mechanisms against the Varroa mite, which should contribute to alleviating current threats and risks to global apiculture and food production security.

О препятствиях на пути “зеленого” пчеловодства во Франции: антропологическая перспектива

Пчелы и широко известные полезные свойства продуктов пчеловодства, которым в общественных дискуссиях во Франции уделялось и уделяется значительное внимание, в течение нескольких предыдущих лет стали предметом интереса французских социальных исследователей. Пчелы фактически превратились в символ кризиса биоразнообразия в стране. Социальные исследовате-ли, включая авторов данной статьи, иногда участвуют в мультидисциплинарных проектах под ру-ководством биологов с целью помочь убедить профессиональных пчеловодов внедрять более эко-логичные практики пчеловодства, особенно в том, что касается борьбы с клещом Варроа – смер-тоносным вредителем пчел. Однако, как выяснилось в ходе нашего исследования на юге Фран-ции, местные пчеловоды не спешат отказываться от привычных методов своей работы. Они про-должают использовать химикаты, которые просты в обращении, дешевы и эффективны, игнори-руя при этом более экологически безопасные, но, по их мнению, более рискованные и сложные в применении техники, такие, как чистка или удаление части пчелиного расплода. В данной статье нами анализируются препятствия на пути внедрения более экологичного пчеловодства во Фран-ции, и исследуется отношение к научному и ненаучному знанию, которое эти препятствия обна-руживают. Over the last few years the amount of space occupied by bees in the French public debate together with the well-known benefits of the products of their hive has attracted the interest of social scien-tists. Indeed, bees have become a symbol of the biodiversity crisis. Social scientists, like us, are sometimes invited to join multi-disciplinary projects run by biologists specializing in bees. The aim of such involvement is to help the biologists convince professional beekeepers to make their practices greener, notably with respect to their handling of the Varroa mite. However, the bee-keepers we studied in the South of France are not keen to give up their conventional practices. Based on chemical products, these are efficient, simple and cheap as opposed to environmentally-friendly, chemical-free techniques (scraping or removal of the brood), which are seen to be riskier and more complicated to implement. This article describes and analyses these obstacles and the relationship to scientific and non-scientific knowledge they reveal.

The application of formic acid to treat varroaatosis in bees in organic animal husbandry

The research aims to evaluate the effectiveness of formic acid as an antiparasitic agent against the varroa mite. The research seeks to evaluate the effectiveness of the antiparasitic agent against the varroa mite and to determine the possibility of using formic acid in organic apiculture. The study was carried out in the nomadic apiaries of Volgograd (apiary 1), Olkhovsky (apiary 2) and Dubovsky (apiary 3) districts of the Volgograd region. The nests were formed by the pairing method with 5 experimental and control families in each apiary after the central beehive (end of July, beginning of August) before the preparation of the bee families for wintering by shrinkage. The authors carried out antiparasitic measures using a gel containing 85% formic acid in the experimental groups twice with an interval of two weeks. The gel is contained in sachets of 30 grams each. The authors placed formic acid over the frames under the canvas (at the rate of 1 sachet per bee colony). The experimental results showed that the treatment measures in the experimental groups had a positive effect on all apiaries. In those groups where formic acid was used, the number of mites decreased by 14.3-28.2% and did not exceed 3.8%. At the same time, in the control groups, the number of mites increased. The treatment measures had a positive effect on the overwintering of the bees. Bee mortality in the autumn-winter-spring period in the experimental groups did not exceed 8.3%. In contrast, in the control families, the wastage was no lower than 18.8%. Also, in two apiaries, one family each died in the control groups. Honey productivity, in the end, was also higher in the experimental groups. The experimental groups produced at least 27.42 kg of honey. The control groups had 17.9 kg of honey per family. Profitability in the experimental groups ranged from 40.87 in Apiary 2 to 60.62% in Apiary 3. This was less than 24.47 per cent in the control apiaries.