Short communication: First data on the prevalence and distribution of pathogens in bumblebees (Bombus terrestris and Bombus pascuorum) from Spain

Abstract

Bumblebees provide pollination services not only to wildflowers but also to economically important crops. In the context of the global decline of pollinators, there is an increasing interest in determining the pathogen diversity of bumblebee species. In this work, wild bumblebees of the species Bombus terrestris and Bombus pascuorum from northern and southern Spain were molecularly screened to detect and estimate prevalence of pathogens. One third of bumblebees were infected: while viruses only infected B. pascuorum, B. terrestris was infected by Apicystis bombi, Crithidia bombi and Nosema bombi. Ecological differences between host species might affect the success of the pathogens biological cycle and consequently infection prevalence. Furthermore, sex of the bumblebees (workers or males), sampling area (north or south) and altitude were important predictors of pathogen prevalence. Understanding how these factors affect pathogens distribution is essential for future conservation of bumblebee wild populations.

Detection of replicative Kashmir Bee Virus and Black Queen Cell Virus in Asian hornet Vespa velutina (Lepelieter 1836) in Italy

“…Both KBV and BQCV have been identified primarily in A. mellifera but also in other Apoidea. The BQCV genome has been detected in Bombus huntii 66,67 , B. atratus 68,69 , Osmia cornuta , O. bicornis , Andrena vaga, Heriades truncorum 70 , B. terrestris 71–76 , B. pascuorum 77 , Xylocopa virginica 78 , B. ignitus 72 , B. impatiens 47,78,79 , B. lucorum 73,80 , B. vagans 78 and B. ternarius 47,78,79 . However, BQCV replicative forms were described only in B. huntii 66,67 .…”

Wide diversity of parasites in Bombus terrestris (Linnaeus, 1758) revealed by a high‐throughput sequencing approach

“…Although these losses have been attributed to multiple agents, the main causes of this decay are the degradation of the habitat due to urbanization and intensive agricultural practices, the use of pesticides and fertilizers, and a battery of biological factors among which are the spread of native and exotic parasites (Goulson et al ., 2015; Meeus et al ., 2018; Sánchez‐Bayo and Wyckhuys, 2019). The identification of these organisms, whose expansion in the environment is mostly driven by the sharing of foraging resources, often relies on classical techniques such as the microscopic examination of the samples (Plischuk et al ., 2011; Murray et al ., 2013; Graystock et al ., 2015) and/or their PCR amplification, usually followed by direct Sanger sequencing of the amplicons (Plischuk et al ., 2011; Glenny et al ., 2017; Jabal‐Uriel et al ., 2017). Although the latter is increasingly replacing microscopy due to its greater sensitivity and ability to differentiate morphologically similar organisms, it can also introduce severe biases in the analyses of prevalence and diversity of parasites.…”

“…The increasing evidence of trypanosomatid co‐occurrence in pollinators (Ravoet et al ., 2015; Bartolomé et al ., 2018; Tripodi et al ., 2018; Bartolomé et al ., 2020) prompted us to evaluate the performance of one of these massive parallel sequencing technologies (Ion PGM TM System; Thermo Fisher Scientific) in 12 trypanosomatid‐positive bumblebees detected in the study by Jabal‐Uriel et al . (2017). These positive samples, which were identified as such by PCR amplification (Meeus et al ., 2010), were also screened for the presence of nosematids and neogregarines using both classical protocols (Jabal‐Uriel et al ., 2017) and next generation sequencing.…”

“…(2017). These positive samples, which were identified as such by PCR amplification (Meeus et al ., 2010), were also screened for the presence of nosematids and neogregarines using both classical protocols (Jabal‐Uriel et al ., 2017) and next generation sequencing.…”

Direct and sensitive detection of a microsporidian parasite of bumblebees using loop-mediated isothermal amplification (LAMP)

“…In the United States, the overall prevalence in nine different bumblebee species was 2.9% (N = 9909), and the highest prevalence was 37.2% (N = 172) 25 . In Spain, the mean prevalence was 1.2% (N = 83) in Bombus terrestris 26 , and in Japan, it was 7.5% (N = 120) and 0% (N = 100) in B. terrestris and native species, respectively 27 . Secondly, although the microsporidia prevalence can be high at the colony level, for example 61.8% of the commercial colonies were infected in Ireland 28 , wild nests of bumblebees are hardly found in the field because they are established under ground or beneath grasses.…”