Honey bee mite Varroa destructor and microsporidium Nosema ceranae are currently considered the most important threats to honey bees and beekeeping. It has been believed that both N. apis and N. ceranae invade exclusively epithelial cells of the honey bee ventriculus. However, some fi ndings suggest that these microsporidia may infect other tissues of honey bees. There are indications that these pathogens could be found in honey bee haemolymph, as the medium for its distribution to anatomically distant tissues. Knowing that V. destructor being an ectoparasitic mite feeds on the honey bee’s haemolymph, the aim of this study was to investigate if DNA of Nosema spp. microsporidia could be found in honey bee haemolymph and in V. destructor.
The study was conducted on bee haemolymph and V. destructor mites from 44 Apis mellifera colonies. From each hive five mite individuals and 10 μL of haemolymph (from 4-5 bees) were used as samples for DNA isolation and PCR detection of Nosema spp.
The DNA of N. ceranae was confi rmed in 61.36% of V. destructor mites and 68.18% of haemolymph samples. This is the first report of N. ceranae DNA in honey bee haemolymph and in V. destructor mites. The finding of DNA of N. ceranae in V. destructor could be interpreted as the result of mite feeding on N. ceranae infected bee haemolymph. However, for a full confi rmation of the vector role of V. destructor in spreading of nosemosis, further microscopy investigations are required for the detection of spores in both investigated matrices (haemolymph and V. destructor internal tissues).
Dajana Davitkov, Uroš Glavinić, Ksenija Nešić, Darko Davitkov, Miloš Vučićević, Vladimir Nešić and Zoran Stanimirović
The main reasons for wildlife forensic research are animal poaching, illegal trade, and falsified game meat products. Small trace amounts, old and degraded materials present the most common samples in revealing criminal activities in this field. This is the reason why it is crucial to use adequate and reliable methods and samples to identify animal species killed outside the hunting season or species protected by law. In this study, different endpoint PCR and real-time PCR protocols were compared in the identification of three Cervidae species (Capreolus capreolus, Cervus elaphus, Dama dama) from old and damaged material found in an enclosed area where the animals were kept. From a total of 129 samples, end point PCR provided results for 119 samples, while real-time PCR was successful in all cases. Also, we created and tested a protocol for simultaneous analyses of different types of samples, which is of great importance as when the amplification is carried out simultaneously it is more cost efficient and speeds up the process.
Zoran Stanimirović, Uroš Glavinić, Nada Lakić, Dejan Radović, Marko Ristanić, Elmin Tarić and Jevrosima Stevanović
Varroa destructor is the most important honey bee parasite. There are various methods used in the control of this mite, but none of them meets all requested criteria, to be safe, effective and easy to apply. The objective of this study was to evaluate the varroacidal efficacy of newly created plant-derived formulation Argus Ras (mixture of extracts of Sophora flavescens, Ginkgo biloba, Gleditsia chinensis and Teucrium chamaedrys) in a field trial. The investigation was conducted on 240 Apis mellifera colonies equalized in respect of brood amount, adult bee population and food reserves. Efficiency was evaluated by applying Argus Ras consecutively with two other acaricides, amitraz and oxalic acid. Average acaricidal efficacy of Argus Ras was 80.89%, being higher of other previously tested essential oils. Besides, it showed a potential in knocking down the mites resistant to other acaricides. It should not be neglected that Argus Ras requires a smaller number of treatments and financial investments than other formulations used for the control of Varroa mites.
Bluetongue, a vector-born disease caused by the Bluetongue virus (BTV) and transmitted by Culicoides biting midges, is considered to be one of the most important diseases of domestic ruminants. The first outbreak of bluetongue in Serbia was reported in 2001, when BTV serotype 9 was identified in sampled materials. In 2014, outbreak of BTV-4 in Serbia caused considerable economic losses affecting sheep, cattle and goats. During this outbreak, BTV-4 was recorded in 644 outbreaks within 49 municipalities, part of 17 administrative regions. From the total number of sheep kept in areas affected by bluetongue (n=1 748 110), 2 083 cases (0.2%) were proven to be BTV-4 infected. Total of 206 infected cattle and 24 infected goats were reported during this investigation period, which represents 0.06% and 0.03% of the total number of cattle and goats kept in affected areas, respectively. The highest incidence of infected sheep, cattle and goats was recorded on the territory covered by veterinary institute of Nis. Recorded lethality in cattle, sheep and goats was 18.45% (n=38), 48.10% (n=1002) and 54.17% (n=13), respectively. The peak of the outbreak was in September and October when 94.43% of the confirmed positive cases, regardless of the species, was recorded. Monitoring of bluetongue disease in Serbia relies on active surveillance programmes aimed at: (i) identification and tracing of susceptible and potentially infected animals and (ii) detection, distribution and prevalence of insect vectors. Vaccination of sheep is planned to be implemented as a control measure against bluetongue in Serbia.
Zoran Stanimirović, Uroš Glavinić, Marko Ristanić, Nevenka Aleksić, Nemanja Jovanović, Branislav Vejnović and Jevrosima Stevanović
Colony losses, including those induced by the colony collapse disorder, are an urgent problem of contemporary apiculture which has been capturing the attention of both apiculturists and the research community. CCD is characterized by the absence of adult dead bees in the hive in which few workers and a queen remain, the ratio between the brood quantity and the number of workers is heavily disturbed in favor of the former, and more than enough food is present. Robbing behavior and pests usually attacking the weakened colony do not occur. In the present paper, the causes of the emergence of this problem are discussed, as well as the measures of its prevention.
The following factors, which lead to colony losses, are analyzed: shortage of high-quality food (pollen and honey); infestation with parasites, primarily with Varroa destructor, and mixed virus infections; bacterial infections (American and European foulbrood), fungal infections (nosemosis and ascosphaerosis) and trypanosomal infections (lotmariosis); and, finally, general management of the apiary.
Certain preventive measures are proposed: (1) providing ample high-quality forage and clean water, (2) avoiding sugarisation, i.e. superfluous use of sugar syrup, (3) meeting the nutritional needs of the colony, (4) when feeding bees, taking care of the timing and the composition of diet, avoiding pure sugar syrup which in excessive quantities may induce energetic and oxidative stress, (5) when there is a shortage of natural feed – honey in the brood chamber – use sugar syrup with natural/artificial supplements to avoid protein starvation, (6) organized control of V. destructor in the colonies is obligatory due to its vector role, and (7) compliance with hygienic and sanitary measures and principles of good apiculture practice and management in apiaries. To conclude, all preventive measures are feasible in compliance with rules and regulations concerning regular spring and autumn bee health monitoring by licensed veterinarians, who can propose adequate treatments if necessary.