Transpuparial transmission of Kashmir bee virus and sacbrood virus in the honey bee (Apis mellifera)

RNA viruses play a significant role in the current high losses of pollinators. Although many studies have focused on the epidemiology of western honey bee (Apis mellifera) viruses at the colony level, the dynamics of virus infection within colonies remains poorly explored. In this study, the two main variants of the ubiquitous honey bee virus DWV as well as three major honey bee viruses (SBV, ABPV and BQCV) were analyzed from Varroa-destructor-parasitized pupae. More precisely, RT-qPCR was used to quantify and compare virus genome copies across honey bee pupae at the individual and subfamily levels (i.e., patrilines, sharing the same mother queen but with different drones as fathers). Additionally, virus genome copies were compared in cells parasitized by reproducing and non-reproducing mite foundresses to assess the role of this vector. Only DWV was detected in the samples, and the two variants of this virus significantly differed when comparing the sampling period, colonies and patrilines. Moreover, DWV-A and DWV-B exhibited different infection patterns, reflecting contrasting dynamics. Altogether, these results provide new insight into honey bee diseases and stress the need for more studies about the mechanisms of intra-colonial disease variation in social insects.

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Detection of Lotmaria passim, Crithidia mellificae and Replicative Forms of Deformed Wing Virus and Kashmir Bee Virus in the Small Hive Beetle (Aethina tumida)

Pathogens ◽

10.3390/pathogens10030372 ◽

2021 ◽

Vol 10 (3) ◽

pp. 372

Author(s):

Antonio Nanetti ◽

James D. Ellis ◽

Ilaria Cardaio ◽

Giovanni Cilia

Keyword(s):

Honey Bee ◽

Aethina Tumida ◽

Small Hive Beetle ◽

Deformed Wing Virus ◽

Queen Cell ◽

Kashmir Bee Virus ◽

Acute Bee Paralysis Virus ◽

Bee Virus ◽

Paralysis Virus ◽

Lotmaria Passim

Knowledge regarding the honey bee pathogens borne by invasive bee pests remains scarce. This investigation aimed to assess the presence in Aethina tumida (small hive beetle, SHB) adults of honey bee pathogens belonging to the following groups: (i) bacteria (Paenibacillus larvae and Melissococcus plutonius), (ii) trypanosomatids (Lotmaria passim and Crithidia mellificae), and (iii) viruses (black queen cell virus, Kashmir bee virus, deformed wing virus, slow paralysis virus, sacbrood virus, Israeli acute paralysis virus, acute bee paralysis virus, chronic bee paralysis virus). Specimens were collected from free-flying colonies in Gainesville (Florida, U.S.A.) in summer 2017. The results of the molecular analysis show the presence of L. passim, C. mellificae, and replicative forms of deformed wing virus (DWV) and Kashmir bee virus (KBV). Replicative forms of KBV have not previously been reported. These results support the hypothesis of pathogen spillover between managed honey bees and the SHB, and these dynamics require further investigation.

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Dynamics of Apis cerana Sacbrood Virus (AcSBV) Prevalence in Apis cerana (Hymenoptera: Apidae) in Northern Taiwan and Demonstration of its Infection in Apis mellifera (Hymenoptera: Apidae)

Journal of Economic Entomology ◽

10.1093/jee/toz174 ◽

2019 ◽

Vol 112 (5) ◽

pp. 2055-2066 ◽

Cited By ~ 1

Author(s):

Chong-Yu Ko ◽

Zong-Lin Chiang ◽

Ruo-Jyun Liao ◽

Zih-Ting Chang ◽

Ju-Chun Chang ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Apis Mellifera ◽

Honey Bee ◽

Apis Cerana ◽

Cross Infection ◽

Prevalence Rates ◽

Sacbrood Virus ◽

Northern Taiwan ◽

Long Term Survey

AbstractSince 2016, Apis cerana sacbrood virus (AcSBV) has been recorded in Taiwan. It is epizootic in Apis cerana (Hymenoptera: Apidae) and causing serious loss of A. cerana. Herein, we performed a long-term survey of AcSBV prevalence in the populations of A. cerana in Northern Taiwan from January 2017 to July 2018. The surveillance of AcSBV prevalence in A. mellifera (Hymenoptera: Apidae) populations was starting and further confirmed by sequencing since April 2017; thus, these data were also included in this survey. In our survey, the average prevalence rates of AcSBV were 72 and 53% in A. cerana and A. mellifera, respectively, in 2017, which decreased to 45 and 27% in 2018. For the spatial analysis of AcSBV in two honey bee populations, Hsinchu showed the highest prevalence, followed by New Taipei, Yilan, Taipei, and Keelung, suggesting that AcSBV might have come from the southern part of Taiwan. Interestingly, the AcSBV prevalence rates from A. cerana and A. mellifera cocultured apiaries gradually synchronized. The result of phylogenetic analysis and comparison of the annual AcSBV prevalence in A. cerana-only, A. mellifera-only, and A. cerana/A. mellifera cocultured sample sites indicate cross-infection between A. cerana and A. mellifera; however, AcSBV may lose the advantage of virulence in A. mellifera. The evidence suggested that the transmission of AcSBV might occur among these two honey bee species in the field. Therefore, A. mellifera may serve as a guard species to monitor AcSBV in A. cerana, but the cross-infection still needs to be surveyed.

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