Toxicity of oxalic acid on in vitro reared honeybee larvae

Varroa destructor is considered as a serious pest of honeybees (Apis mellifera) and its resistance to acaricides has been reported since the early 1990s. Because large colony loses are yearly reported from over the world, new methods of treatment for Varroa mites are still in focus of many scientists. In our bioassay, we determined the lethal concentration 72 h LC50 of 2.425% oxalic acid solution following single spray exposure of honeybee larvae under laboratory conditions (Guideline OECD 237, 2013).Varroa destructor is considered as a serious pest of honeybees (Apis mellifera) and its resistance to acaricides has been reported since the early 1990s. Because large colony loses are yearly reported from over the world, new methods of treatment for Varroa mites are still in focus of many scientists. In our bioassay, we determined the lethal concentration 72 h LC50 of 2.425% oxalic acid solution following single spray exposure of honeybee larvae under laboratory conditions (Guideline OECD 237, 2013)

The use of parasites as bioindicators of pesticide exposure

Organisms used in risk assessment of pesticides must be the most sensitive ones to pesticides exposure. The aim of this study was to observe the effect of two commercial pesticide products (containing glyphosate and tolylfluanid) to larval stages of parasites Cooperia curticei, Ostertagia circumcincta, Haemonchus contortus and Trichostrongylus axei. There were two concentrations tested for each product vs. control group. Larvae (500 individuals/Petri dish) were incubated at 27 °C and observed daily for 42 days

Vairimorpha apis Versus Vairimorpha ceranae, Replacement or Dynamic Prevalence?

Nosematosis is currently a frequently discussed disease of bees caused by two species of microsporidia: Vairimorpha apis, and Vairimorpha ceranae. Vairimorpha apis represents the original species of Apis mellifera parasite, and Vairimorpha ceranae, is a species introduced from Asia. In the last two decades, epidemiological data on the growth of the prevalence of V. ceranae infection have increased, which has led to its dominant position at the expense of its congener V. apis, practically all over the world. This process is assumed to be the result of asymmetric competition within the host, where V. ceranae, showed a better ability to adapt to higher temperatures, which was first manifested by its spread in warmer climate zones. However, several results of studies from recent years somewhat unexpectedly showed that it is premature to talk about the complete replacement of V. apis by V. ceranae. They pointed to a greater influence of seasonality and average temperatures in winter and summer in a given year on the result of the current prevalence of infection and co-infection of Vairimorpha spp., regardless of the climatic zone in which the colonies were located. Considering the different clinical and subclinical manifestations of infection caused by V. apis, and V. ceranae, and its impact on the defense, survival and productivity of bee colonies, the aim of our work was to analyze the factors affecting the distribution and prevalence of Vairimorpha spp

Body Characteristic of Drones of Different Origin

Computer-based methods help beekeepers and scientists in apidology and bee research. Using software Optika Vision Pro in this study, three body morphological characteristics has been applied to honeybees’ drones (Apis mellifera carnica) of different origin in identification of difference among them. All three measured body morphological characteristics (body length, forewing length, and head length) were statistically different between drones originated from colonies with mated queens and drones originated from colonies with unfertilised queen and/or with unfertilised worker bee(s), respectively, thus making them potentially more successful in queen fertilization and secondary colony development and productivity

The Evaluation of Mercury in Honey Bees and their Products from Eastern Slovakia

Heavy metals are a major source of environmental pollution, and have a significant impact on ecological quality of the environment. The human activity affects the environment so there is a high risk of metal accumulation. Heavy metals contaminate not only the environment but accumulate in the human body, from which it is difficult to degrade them. The long tradition of beekeeping in the world is proof that bees are irreplaceable and important pollinators of plants and crops, which are necessary to maintain the prosperity of agriculture. Beekeeping up to the present is still popular and is ecologically and economically significant. The aim of this study was to determine total mercury content in the body of bees and their products (bee pollen, honey) of selected locations in eastern Slovakia, evaluation of obtained results according to current standards and compared to the values established by the Food Codex of the Slovak Republic and The European Food Safety Authority (EFSA), according to which mercury is a metal that is released into the environment from both natural sources and as a result of human activity. The mercury element can occur as inorganic mercury (mercurous (Hg22+) and mercuric (Hg2+) cations), and organic mercury. Methylmercury (MeHg) is by far the most common form of organic mercury in the food chain. The tested bees and their products were collected from apiaries located in the area of the University of Veterinary Medicine and Pharmacy in Košice and the apiary in Rozhanovce. The evaluation of the impact of environmental contamination by hazardous substances is very important regards to the protection of bees and not least to protect the health of people as consumers of food products containing residues of industrial production

Honey bees metapopulations, parasites, and landscape - search for possible relationships: case study Slovakia

The loss of bees is a relatively well-known worldwide phenomenon. Many papers examine the direct influence of different factors on global bees lost. However, a look at this problem with the intentions of host-parasite-environment interactions is rare. This paper post tries to prove possible connections among bees, their parasites and landscape structure. During the research at 27 suitable sites across Slovakia, Nosema spp. spores were detected in two samples (7.41 % of examined apiaries) and Varroa destructor in a total of 41 % of samples (mean prevalence of 0.57). Significant differences were found in mites infestation in altitudes up to 500 m and over 500 m, and at sites with different ES. Considering the landscape structure, Varroa infestation was significantly positively influenced by the presence of discontinuous urban fabrics

The Application of MALDI-TOF MS for a Variability Study of <i>Paenibacillus larvae</i>

In recent decades, the significant deterioration of the health status of honey bees has been observed throughout the world. One of the most severe factors affecting the health of bee colonies worldwide is American foulbrood disease. This devastating disease, with no known cure, is caused by the Gram-positive spore-forming bacteria of Paenibacillus larvae species. At present, DNA-based methods are being used for P. larvae identification and typing. In our study, we compare two of the most advanced DNA-based technologies (rep-PCR and 16S rRNA analyses) with MALDI-TOF MS fingerprinting to evaluate P. larvae variability in Central Europe. While 16S rRNA analysis presents a very limited variation among the strains, MALDI-TOF MS is observed to be more efficient at differentiating P. larvae. Remarkably, no clear correlation is observed between whole-genome rep-PCR fingerprinting and MALDI-TOF MS-based typing. Our data indicate that MALDI-TOF protein profiling provides accurate and cost-effective methods for the rapid identification of P. larvae strains and provides novel perspectives on strain diversity compared to conventional DNA-based genotyping approaches. The current study provides a good foundation for future studies