Recent declines in insect abundances, especially populations of wild pollinators, pose a threat to many natural and agricultural ecosystems. Traditional species monitoring relies on morphological character identification and is inadequate for efficient and standardized surveys. DNA barcoding has become a standard approach for molecular identification of organisms, aiming to overcome the shortcomings of traditional biodiversity monitoring. However, its efficacy depends on the completeness of reference databases. Large DNA barcoding efforts are (almost entirely) lacking in many European countries and such patchy data limit Europe‐wide analyses of precisely how to apply DNA barcoding in wild bee identification. Here, we advance towards an effective molecular identification of European wild bees. We conducted a high‐effort survey of wild bees at the junction of central and southern Europe and DNA barcoded all collected morphospecies. For global analyses, we complemented our DNA barcode dataset with all relevant European species and conducted global analyses of species delimitation, general and genus‐specific barcoding gaps and examined the error rate in DNA data repositories. We found that (i) a sixth of all specimens from Slovenia could not be reliably identified, (ii) species delimitation methods show numerous systematic discrepancies, (iii) there is no general barcoding gap across all bees and (iv) the barcoding gap is genus specific, but only after curating for errors in DNA data repositories. Intense sampling and barcoding efforts in underrepresented regions and strict curation of DNA barcode repositories are needed to enhance the use of DNA barcoding for the identification of wild bees.

Slovenia has a long tradition of beekeeping and a high density of honeybee colonies, but less is known about bumblebees and their pathogens. Therefore, a study was conducted to define the incidence and prevalence of pathogens in bumblebees and to determine whether there are links between infections in bumblebees and honeybees. In 2017 and 2018, clinically healthy workers of bumblebees (Bombus spp.) and honeybees (Apis mellifera) were collected on flowers at four different locations in Slovenia. In addition, bumblebee queens were also collected in 2018. Several pathogens were detected in the bumblebee workers using PCR and RT-PCR methods: 8.8% on acute bee paralysis virus (ABPV), 58.5% on black queen cell virus (BQCV), 6.8% on deformed wing virus (DWV), 24.5% on sacbrood bee virus (SBV), 15.6% on Lake Sinai virus (LSV), 16.3% on Nosema bombi, 8.2% on Nosema ceranae, 15.0% on Apicystis bombi and 17.0% on Crithidia bombi. In bumblebee queens, only the presence of BQCV, A. bombi and C. bombi was detected with 73.3, 26.3 and 33.3% positive samples, respectively. This study confirmed that several pathogens are regularly detected in both bumblebees and honeybees. Further studies on the pathogen transmission routes are required.

In recent years, there has been growing evidence that certain types of honeybee viruses could be transmitted between different pollinators. Within a voluntary monitoring programme, 180 honeybee samples (Apis mellifera carnica) were collected from affected apiaries between 2007 and 2018. Also from August 2017 to August 2018, a total 148 samples of healthy bumblebees (Bombus lapidarius, B. pascuorum, B. terrestris, B. lucorum, B. hortorum, B. sylvarum, B. humilis) were collected at four different locations in Slovenia, and all samples were tested by using RT-PCR methods for six honeybee viruses. Direct sequencing of a total 158 positive samples (acute bee paralysis virus (ABPV n = 33), black queen cell virus (BQCV n = 75), sacbrood bee virus (SBV n = 25) and Lake Sinai virus (LSV n = 25)) was performed from obtained RT-PCR products. The genetic comparison of identified positive samples of bumblebees and detected honeybee field strains of ABPV, BQCV, SBV, and LSV demonstrated 98.74% to 100% nucleotide identity between both species. This study not only provides evidence that honeybees and bumblebees are infected with genetically identical or closely related viral strains of four endemically present honeybee viruses but also detected a high diversity of circulating strains in bumblebees, similar as was observed among honeybees. Important new genetic data for endemic strains circulating in honeybees and bumblebees in Slovenia are presented.

Objectives: To estimate the lifetime prevalence of first and recurrent systemic allergic reaction to bee venom among Slovenian beekeepers. Additionally, we aimed to elucidate the risk factors predisposing beekeepers to developing systemic allergic reaction to bee venom. Methods: A nationwide cross-sectional study was conducted among 1,080 beekeepers who are members of the Slovenian beekeeper’s association, between 1 November 2021 and 31 May 2023. Epidemiological data were collected using a validated questionnaire, with the clinician-confirmed observed health outcome. Results: The estimated overall lifetime prevalence of self-reported first systemic allergic reaction to bee venom was 9.4% (102/1,080), with 40.7% (24/59) of the clinician-confirmed cases being severe (grade III-IV according to the Mueller classification). The estimated overall lifetime prevalence of reported recurrent systemic allergic reaction to bee venom was lower at 3.7% (40/1,080), with 60.0% (9/15) of the clinician-confirmed cases being severe (grade III-IV according to the Mueller classification). Risk factors associated with the first systemic allergic reaction to bee venom included age, male sex, number of bee stings per season, a history of large local reaction and experiencing nasal symptoms while working at hives. Younger male beekeepers, with a low number of bee stings per season, a history of large local reaction and nasal symptoms while working at hives, are at a high risk of having systemic allergic reaction to bee venom. Conclusions: High lifetime prevalence of clinician-confirmed severe first and recurrent systemic allergic reaction to bee venom underscored the importance of targeted public health strategies and clinical interventions to protect this high-risk population.

Pollinators communities differ across years and crops | Danilo Bevk, Janez Prešern | Agricultural Journals