Genetic detection and quantification of Nosema apis and N. ceranae in the honey bee

The incidence of nosemosis has increased in recent years due to an emerging infestation of Nosema ceranae in managed honey bee populations in much of the world. A real-time PCR assay was developed to facilitate detection and quantification of both Nosema apis and N. ceranae in both single bee and pooled samples. The assay is a multiplexed reaction in which both species are detected and quantified in a single reaction. The assay is highly sensitive and can detect single copies of the target sequence. Real-time PCR results were calibrated to spore counts generated by standard microscopy procedures. The assay was used to assess bees from commercial apiaries sampled in November 2008 and March 2009. Bees from each colony were pooled. A large amount of variation among colonies was evident, signifying the need to examine large numbers of colonies. Due to sampling constraints, a subset of colonies (from five apiaries) was sampled in both seasons. In November, N. apis levels were 1212 ± 148 spores/bee and N. ceranae levels were 51,073 ± 31,155 spores/bee. In March, no N. apis was detected, N. ceranae levels were 11,824 ± 6304 spores/bee. Changes in N. ceranae levels were evident among apiaries, some increasing and other decreasing. This demonstrates the need for thorough sampling of apiaries and the need for a rapid test for both detection and quantification of both Nosema spp. This assay provides the opportunity for detailed study of disease resistance, infection kinetics, and improvement of disease management practices for honey bees.     

Evidence for emerging parasites and pathogens influencing outbreaks of stress-related diseases like chalkbrood

In agriculture, honey bees play a critical role as commercial pollinators of crop monocultures which depend on insect pollination. Hence, the demise of honey bee colonies in Europe, USA, and Asia caused much concern and initiated many studies and research programmes aiming at elucidating the factors negatively affecting honey bee health and survival. Most of these studies look at individual factors related to colony losses. In contrast, we here present our data on the interaction of pathogens and parasites in honey bee colonies. We performed a longitudinal cohort study over 6 years by closely monitoring 220 honey bee colonies kept in 22 apiaries (ten randomly selected colonies per apiary). Observed winter colony losses varied between 4.8% and 22.4%; lost colonies were replaced to ensure a constant number of monitored colonies over the study period. Data on mite infestation levels, infection with viruses, Nosema apis and Nosema ceranae, and recorded outbreaks of chalkbrood were continuously collected. We now provide statistical evidence (i) that Varroa destructor infestation in summer is related to DWV infections in autumn, (ii) that V. destructor infestation in autumn is related to N. apis infection in the following spring, and most importantly (iii) that chalkbrood outbreaks in summer are related to N. ceranae infection in the preceding spring and to V. destructor infestation in the same season. These highly significant links between emerging parasites/pathogens and established pathogens need further experimental proof but they already illustrate the complexity of the host–pathogen-interactions in honey bee colonies.     

First Detection of the Larval Chalkbrood Disease Pathogen Ascosphaera apis (Ascomycota: Eurotiomycetes: Ascosphaerales) in Adult Bumble Bees

Fungi in the genus Ascosphaera (Ascomycota: Eurotiomycetes: Ascosphaerales) cause chalkbrood disease in larvae of bees. Here, we report the first-ever detection of the fungus in adult bumble bees that were raised in captivity for studies on colony development. Wild queens of Bombus griseocollis, B. nevadensis and B. vosnesenskii were collected and maintained for establishment of nests. Queens that died during rearing or that did not lay eggs within one month of capture were dissected, and tissues were examined microscopically for the presence of pathogens. Filamentous fungi that were detected were plated on artificial media containing broad spectrum antibiotics for isolation and identification. Based on morphological characters, the fungus was identified as Ascosphaera apis (Maasen ex Claussen) Olive and Spiltoir, a species that has been reported earlier only from larvae of the European honey bee, Apis mellifera, the Asian honey bee, Apis cerana, and the carpenter bee Xylocopa californica arizonensis. The identity of the fungus was confirmed using molecular markers and phylogenetic analysis. Ascosphaera apis was detected in queens of all three bumble bee species examined. Of 150 queens dissected, 12 (8%) contained vegetative and reproductive stages of the fungus. Both fungal stages were also detected in two workers collected from colonies with Ascosphaera-infected B. nevadensis queens. In this study, wild bees could have been infected prior to capture for rearing, or, the A. apis infection could have originated via contaminated European honey bee pollen fed to the bumble bees in captivity. Thus, the discovery of A. apis in adult bumble bees in the current study has important implications for commercial production of bumble bee colonies and highlights potential risks to native bees via pathogen spillover from infected bees and infected pollen.     

Presence of <Emphasis Type="Italic">Ascosphaera apis</Emphasis>, the causative agent of chalkbrood disease,in honeybees <Emphasis Type="Italic">Apis mellifera</Emphasis> (Hymenoptera: Apidae) in Japan

The presence of Ascosphaera apis, a fungus that is the causative agent of chalkbrood disease, was surveyed in Japan using a diagnostic polymerase chain reaction (PCR). A total of 336 individual European honeybees Apis mellifera were taken from 25 different apiaries in various regions of Japan. Of the 112 colonies surveyed, A. apis was detected in 27 colonies (24.1%). Positive results by PCR were obtained from 49 out of 336 surveyed individuals (14.6%). Based on these results, the distribution of A. apis in A. mellifera is widespread across Japan and does not exhibit significant differences between geographic areas. DNA sequences of the ITS and 5.8S rRNA region from all 17 isolates of A. apis were identical, even though they were from geographically distinct areas in Japan. It is suggested that no intra-species variation may be due to a recent bottleneck effect probably caused by humans before geographical expansion of the fungus.     

The Honey Bee Pathosphere of Mongolia: European Viruses in Central Asia

Parasites and pathogens are apparent key factors for the detrimental health of managed European honey bee subspecies, Apis mellifera. Apicultural trade is arguably the main factor for the almost global distribution of most honey bee diseases, thereby increasing chances for multiple infestations/infections of regions, apiaries, colonies and even individual bees. This imposes difficulties to evaluate the effects of pathogens in isolation, thereby creating demand to survey remote areas. Here, we conducted the first comprehensive survey for 14 honey bee pathogens in Mongolia (N = 3 regions, N = 9 locations, N = 151 colonies), where honey bee colonies depend on humans to overwinter. In Mongolia, honey bees, Apis spp., are not native and colonies of European A. mellifera subspecies have been introduced ~60 years ago. Despite the high detection power and large sample size across Mongolian regions with beekeeping, the mite Acarapis woodi, the bacteria Melissococcus plutonius and Paenibacillus larvae, the microsporidian Nosema apis, Acute bee paralysis virus, Kashmir bee virus, Israeli acute paralysis virus and Lake Sinai virus strain 2 were not detected, suggesting that they are either very rare or absent. The mite Varroa destructor, Nosema ceranae and four viruses (Sacbrood virus, Black queen cell virus, Deformed wing virus (DWV) and Chronic bee paralysis virus) were found with different prevalence. Despite the positive correlation between the prevalence of V. destructor mites and DWV, some areas had only mites, but not DWV, which is most likely due to the exceptional isolation of apiaries (up to 600 km). Phylogenetic analyses of the detected viruses reveal their clustering and European origin, thereby supporting the role of trade for pathogen spread and the isolation of Mongolia from South-Asian countries. In conclusion, this survey reveals the distinctive honey bee pathosphere of Mongolia, which offers opportunities for exciting future research.     

Estimation of the influence of selected products on co-infection with N. apis/N. ceranae in Apis mellifera using real-time PCR

To protect the world’s honey bee population many scientific centres are searching for products and methods that control nosemosis. Real-time PCR was used to assess infection level in worker bees infected with Nosema spp. in bee colonies co-infected with Nosema apis and Nosema ceranae after the administration of three products (Nozevit, ApiHerb and ApiX) and sugar syrup. The study was conducted in the field condition therefore there was no possibility to affect the number of spores in the selected material. The study demonstrated considerable differences in the number of spores of individual Nosema spp. in the analysed samples of bees. HSD Tukey’s test showed that the statistically significant effect on limiting the N. apis invasion had ApiX (p – 0.049). Nozevit, Apiherb and syrup showed no statistically significant effect on reducing the amount of N. apis spores. The same test showed that the statistically significant effect on limiting the N. ceranae invasion had: Nozevit (p – 0.014), Apiherb (p – 0.032), ApiX (p – 0.034) and syrup (p – 0.033). There was no statistically significant decrease in the N. ceranae spores in the control group.     

Iridovirus and microsporidian linked to honey bee colony decline

Background

In 2010 Colony Collapse Disorder (CCD), again devastated honey bee colonies in the USA, indicating that the problem is neither diminishing nor has it been resolved. Many CCD investigations, using sensitive genome-based methods, have found small RNA bee viruses and the microsporidia, Nosema apis and N. ceranae in healthy and collapsing colonies alike with no single pathogen firmly linked to honey bee losses.

Methodology/Principal Findings

We used Mass spectrometry-based proteomics (MSP) to identify and quantify thousands of proteins from healthy and collapsing bee colonies. MSP revealed two unreported RNA viruses in North American honey bees, Varroa destructor-1 virus and Kakugo virus, and identified an invertebrate iridescent virus (IIV) (Iridoviridae) associated with CCD colonies. Prevalence of IIV significantly discriminated among strong, failing, and collapsed colonies. In addition, bees in failing colonies contained not only IIV, but also Nosema. Co-occurrence of these microbes consistently marked CCD in (1) bees from commercial apiaries sampled across the U.S. in 2006–2007, (2) bees sequentially sampled as the disorder progressed in an observation hive colony in 2008, and (3) bees from a recurrence of CCD in Florida in 2009. The pathogen pairing was not observed in samples from colonies with no history of CCD, namely bees from Australia and a large, non-migratory beekeeping business in Montana. Laboratory cage trials with a strain of IIV type 6 and Nosema ceranae confirmed that co-infection with these two pathogens was more lethal to bees than either pathogen alone.

Conclusions/Significance

These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe, and Asia. We next need to characterize the IIV and Nosema that we detected and develop management practices to reduce honey bee losses.     

Lactobacillus salivarius A3iob Reduces the Incidence of Varroa destructor and Nosema Spp. in Commercial Apiaries Located in the Northwest of Argentina

Lactobacillus salivarius A3iob was administered to productive colonies belonging to commercial apiaries of small beekeepers (around 30–50 hives each one), from four departments of the province of Jujuy (Argentina): Yala, Tilquiza, El Carmen, and Los Alisos. The incidence of Varroa destructor and Nosema spp., before and after winter, was monitored during 2 years of study (2014–2015). Depending on the geographical location of each apiary and the application time, a monthly dose of the bacteria (10⁵ CFU/mL) reduced the levels of varroasis between 50 and 80%. Interestingly, L. salivarius A3iob cells remitted the percentage of the mites to undetectable values in an apiary treated with flumethrin (at Yala, Yungas region).

On the other hand, the spore levels of Nosema spp. in the lactobacilli-treated colonies also depended on the apiary and the year of application, but a significant decrease was mainly observed in the post-winter period. However, at Rivera (El Carmen’s department), no significant changes were detected in both parameters.

These results obtained after 2 years of work suggest that delivering L. salivarius A3iob cells to the bee colonies can become a new eco-friendly tool to cooperate with the control of these bees’ pests.

     

Prevalence and Seasonal Variations of Six Bee Viruses in Apis mellifera L. and Varroa destructor Mite Populations in France

A survey of six bee viruses on a large geographic scale was undertaken by using seemingly healthy bee colonies and the PCR technique. Samples of adult bees and pupae were collected from 36 apiaries in the spring, summer, and autumn during 2002. Varroa destructor samples were collected at the end of summer following acaricide treatment. In adult bees, during the year deformed wing virus (DWV) was found at least once in 97% of the apiaries, sacbrood virus (SBV) was found in 86% of the apiaries, chronic bee paralysis virus (CBPV) was found in 28% of the apiaries, acute bee paralysis virus (ABPV) was found in 58% of the apiaries, black queen cell virus (BQCV) was found in 86% of the apiaries, and Kashmir bee virus (KBV) was found in 17% of the apiaries. For pupae, the following frequencies were obtained: DWV, 94% of the apiaries; SBV, 80% of the apiaries; CBPV, none of the apiaries; ABPV, 23% of the apiaries; BQCV, 23% of the apiaries; and KBV, 6% of the apiaries. In Varroa samples, the following four viruses were identified: DWV (100% of the apiaries), SBV (45% of the apiaries), ABPV (36% of the apiaries), and KBV (5% of the apiaries). The latter findings support the putative role of mites in transmitting these viruses. Taken together, these data indicate that bee virus infections occur persistently in bee populations despite the lack of clinical signs, suggesting that colony disease outbreaks might result from environmental factors that lead to activation of viral replication in bees.     

Host sharing by the honey bee parasites Lotmaria passim and Nosema ceranae

The trypanosome Lotmaria passim and the microsporidian Nosema ceranae are common parasites of the honey bee, Apis mellifera, intestine, but the nature of interactions between them is unknown. Here, we took advantage of naturally occurring infections and quantified infection loads of individual workers (N = 408) originating from three apiaries (four colonies per apiary) using PCR to test for interactions between these two parasites. For that purpose, we measured the frequency of single and double infections, estimated the parasite loads of single and double infections, and determined the type of correlation between both parasites in double infections. If interactions between both parasites are strong and antagonistic, single infections should be more frequent than double infections, double infections will have lower parasite loads than single infections, and double infections will present a negative correlation. Overall, a total of 88 workers were infected with N. ceranae, 53 with L. passim, and eight with both parasites. Although both parasites were found in all three apiaries, there were significant differences among apiaries in the proportions of infected bees. The data show no significant differences between the expected and observed frequencies of single‐ and double‐infected bees. While the infection loads of individual bees were significantly higher for L. passim compared to N. ceranae, there were no significant differences in infection loads between single‐ and double‐infected hosts for both parasites. These results suggest no strong interactions between the two parasites in honey bees, possibly due to spatial separation in the host. The significant positive correlation between L. passim and N. ceranae infection loads in double‐infected hosts therefore most likely results from differences among individual hosts rather than cooperation between parasites. Even if hosts are infected by multiple parasites, this does not necessarily imply that there are any significant interactions between them.     

Morphogenetic diversity of the honeybee <Emphasis Type="Italic">Apis mellifera</Emphasis> L. from the mountain-forest zone of Crimea

By using morphometric and molecular-genetic methods, the population of honeybees of apiaries located in the mountain-forest zone of the Crimean Peninsula under conditions of prolonged isolation from other bee farms of the peninsula was studied. The hypothesis that the bees of this apiary may show signs of lost Crimean bees was analyzed. The complex of morphological traits makes the bees of the examined apiaries closer to Italian, Krajina, and Ukrainian steppe bees and, to a lesser extent, to Carpathian bees. The results of molecular genetic analysis of the initial part of the mtDNA COI gene from GenBank for the races under consideration revealed the evolutionary proximity of the bees studied to representatives of Italian bees. The bees of the isolated apiary are united into a single haplotype. The sequences of the mtDNA COI locus were obtained from Carpathian bees from Moscow oblast and Tajikistan. In terms of differences between the Italian bee haplotype and haplotypes of bees from other regions related to Carpathian bees, it is suggested that the haplotypes of the apiary studied are more similar to Carpathian bees. The investigations do not reject the hypothesis that bees of the isolated apiary may have traits typical of Crimean bees.     

Testing muzzle and ploy devices to reduce predation of bees by Asian hornets

Since its accidental introduction in 2004, the Asian yellow-legged hornet (Vespa velutina) has quickly spread in France. V. velutina specializes in the emblematic honeybee, Apis mellifera which are unable to protect their colonies efficiently against this fierce new predator. Here, we investigated whether two defence devices, a ploy and a muzzle, can protect bee colonies. Our results showed that neither device was able to reduce the number of hornets present in front of the hive or their predation efficiency (i.e. the number of captured bees). However, we found more flying bees and a smaller bee carpet in the presence of a muzzle, evidence that this very cheap method of protection can reduce the hornets’ impact on the activity of the bee colony and thus probably enabling its survival. We also showed that the number of agonistic interactions among V. velutina individuals increased with the number of hornets but without influencing the predation rate in our experimental conditions. The threat to honey bees is now well described, but the Asian yellow-legged hornet very likely has an impact on another insect species that has been the subject of far fewer studies: The native European hornet (Vespa cabro). Monitoring of several apiaries suggests that high densities of both V. velutina and V. crabro are exclusive and that the two species are engaged in an exploitative competition interaction. We are thus already in a position to underline the need for combined protection, as well as for further studies to better understand the ecology of V. velutina, to reduce the damage they cause.     

Polar tube protein gene diversity among Nosema ceranae strains derived from a Greek honey bee health study

Honey bee samples from 54 apiaries originating from 37 geographic locations of Greece were screened for Nosema apis and Nosema ceranae. Furthermore 15 samples coming from 12 geographic locations were screened also for Paenibacilluslarvae and Melissococcus plutonius and seven honey bee virus species, for the first time on a nation-wide level. There was a tendency in finding proportionally higher spore counts in samples from apiaries that suffered important colony losses. P. larvae bacteria were identified in two samples and each of the tested bee viruses could be detected in at least one of the examined samples, with IAPV, CBPV and SBV being the least abundant and BQCV and DWV being the most abundant. In the study we focused on polymorphism of a N. ceranae gene encoding a polar tube protein (PTP) as similar genes were proven to be highly polymorphic in the microsporidian parasites Encephalitozoon cuniculi and Encephalitozoon hellem. The polymorphism observed in the PTP gene sequences from a single sample (bee hive) was unexpected and can thus be considered to be a major obstacle for genotyping.     

Infra-Population and -Community Dynamics of the Parasites Nosema apis and Nosema ceranae,and Consequences for Honey Bee (Apis mellifera) Hosts

Nosema spp. fungal gut parasites are among myriad possible explanations for contemporary increased mortality of western honey bees (Apis mellifera, hereafter honey bee) in many regions of the world. Invasive Nosema ceranae is particularly worrisome because some evidence suggests it has greater virulence than its congener N. apis. N. ceranae appears to have recently switched hosts from Asian honey bees (Apis cerana) and now has a nearly global distribution in honey bees, apparently displacing N. apis. We examined parasite reproduction and effects of N. apis, N. ceranae, and mixed Nosema infections on honey bee hosts in laboratory experiments. Both infection intensity and honey bee mortality were significantly greater for N. ceranae than for N. apis or mixed infections; mixed infection resulted in mortality similar to N. apis parasitism and reduced spore intensity, possibly due to inter-specific competition. This is the first long-term laboratory study to demonstrate lethal consequences of N. apis and N. ceranae and mixed Nosema parasitism in honey bees, and suggests that differences in reproduction and intra-host competition may explain apparent heterogeneous exclusion of the historic parasite by the invasive species.     

Boron fertilizers in rape – a risk for honey bees?

Rape (Brassica napus L.) is foraged intensively by honey bees (Apis mellifera). Pesticide applications during bloom are sometimes combined with foliar boron fertilizer applications. Boron has insecticidal properties, and therefore, risk to honey bees cannot be excluded. This study was conducted to test whether foliar boron fertilizers could be hazardous for bees under real field conditions. Six colonies were transferred to a rape field in bloom which was treated with boron (1 kg/ha). Six control colonies were transferred to an untreated rape field approximately 7 km away. Performance parameters of the colonies were measured. Samples of honey and beebread were collected from all colonies before and after boron fertilizer application. The contents of boron and of Al, Cd, Cr, Fe, K, Mn, Ni, P, Pb, S and Zn were measured in honey by inductively coupled plasma mass spectroscopy (ICP MS) and by ICP–atomic emission spectroscopy (ICP‐OES). No significant differences were found in honey yield (P = 0.622), number of capped brood (P = 0.089), number of uncapped brood (P = 0.123) or number of bees (P = 0.87). Application of boron fertilizer did not affect the concentration of boron in honey (P = 0.656) or beebread (P = 0.665). The concentrations of other elements confirmed the suitability of rape nectar for bee nutrition. This study suggests that the application of foliar boron fertilizers in blooming rape is not hazardous for bee colonies.     

Seasonal dynamics and co‐occurrence patterns of honey bee pathogens revealed by high‐throughput RT‐qPCR analysis

The health of the honey bee Apis mellifera is challenged by introduced parasites that interact with its inherent pathogens and cause elevated rates of colony losses. To elucidate co‐occurrence, population dynamics, and synergistic interactions of honey bee pathogens, we established an array of diagnostic assays for a high‐throughput qPCR platform. Assuming that interaction of pathogens requires co‐occurrence within the same individual, single worker bees were analyzed instead of collective samples. Eleven viruses, four parasites, and three pathogenic bacteria were quantified in more than one thousand single bees sampled from sixteen disease‐free apiaries in Southwest Germany. The most abundant viruses were black queen cell virus (84%), Lake Sinai virus 1 (42%), and deformed wing virus B (35%). Forager bees from asymptomatic colonies were infected with two different viruses in average, and simultaneous infection with four to six viruses was common (14%). Also, the intestinal parasites Nosema ceranae (96%) and Crithidia mellificae/Lotmaria passim (52%) occurred very frequently. These results indicate that low‐level infections in honey bees are more common than previously assumed. All viruses showed seasonal variation, while N. ceranae did not. The foulbrood bacteria Paenibacillus larvae and Melissococcus plutonius were regionally distributed. Spearman's correlations and multiple regression analysis indicated possible synergistic interactions between the common pathogens, particularly for black queen cell virus. Beyond its suitability for further studies on honeybees, this targeted approach may be, due to its precision, capacity, and flexibility, a viable alternative to more expensive, sequencing‐based approaches in nonmodel systems.     

Prevalence and seasonal variations of six bee viruses in Apis mellifera L. and Varroa destructor mite populations in France

A survey of six bee viruses on a large geographic scale was undertaken by using seemingly healthy bee colonies and the PCR technique. Samples of adult bees and pupae were collected from 36 apiaries in the spring, summer, and autumn during 2002. Varroa destructor samples were collected at the end of summer following acaricide treatment. In adult bees, during the year deformed wing virus (DWV) was found at least once in 97% of the apiaries, sacbrood virus (SBV) was found in 86% of the apiaries, chronic bee paralysis virus (CBPV) was found in 28% of the apiaries, acute bee paralysis virus (ABPV) was found in 58% of the apiaries, black queen cell virus (BQCV) was found in 86% of the apiaries, and Kashmir bee virus (KBV) was found in 17% of the apiaries. For pupae, the following frequencies were obtained: DWV, 94% of the apiaries; SBV, 80% of the apiaries; CBPV, none of the apiaries; ABPV, 23% of the apiaries; BQCV, 23% of the apiaries; and KBV, 6% of the apiaries. In Varroa samples, the following four viruses were identified: DWV (100% of the apiaries), SBV (45% of the apiaries), ABPV (36% of the apiaries), and KBV (5% of the apiaries). The latter findings support the putative role of mites in transmitting these viruses. Taken together, these data indicate that bee virus infections occur persistently in bee populations despite the lack of clinical signs, suggesting that colony disease outbreaks might result from environmental factors that lead to activation of viral replication in bees.     

Performance of honeybee colonies located in neonicotinoid‐treated and untreated cornfields in Quebec

Twenty‐two honeybee (Apis mellifera) colonies were placed in four different cornfield areas in order to study the potential in situ effects of seed‐coated systemic neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Two apiaries were located in two independent neonicotinoid‐treated cornfield areas and two others in two independent untreated cornfield areas used as controls. These experimental hives were extensively monitored for their performance and health traits over a period of one year. Trapped pollen was collected and microscopically identified to define the visited flowers and the amount of corn pollen collected by bees. Liquid chromatography–mass spectrometry was performed to detect pesticide residues in honeybee foragers and trapped pollen. Honeybee colonies located in neonicotinoid‐treated cornfields expressed significantly higher varroa mite loads than those in untreated cornfields. However, brood production and colony weight were less disturbed by the treatment factor. Sublethal doses of neonicotinoids were detected in the trapped corn pollen and none in bee foragers. Overall, our results show that forager bees collected 20% of corn pollen containing variable concentrations of neonicotinoids. Colonies located in treated cornfields expressed higher varroa loads and long‐term mortality than those in untreated cornfields. On the other hand, no significant differences were observed regarding the brood production and colony weight.     

Molecular Prevalence of Acarapis Mite Infestations in Honey Bees in Korea

Acarapis mites, including Acarapis woodi, Acarapis externus, and Acarapis dorsalis, are parasites of bees which can cause severe damage to the bee industry by destroying colonies and decreasing honey production. All 3 species are prevalent throughout many countries including UK, USA, Iran, Turkey, China, and Japan. Based on previous reports of Acarapis mites occurring in northeast Asia, including China and Japan, we investigated a survey of Acarapis mite infestations in honey bees in Korean apiaries. A total of 99 colonies of Apis mellifera were sampled from 5 provinces. The head and thorax of 20 bees from each colony were removed for DNA extraction. PCR assays were performed with 3 primer sets, including T, A, and K primers. Results indicated that 42.4% (42/99) of samples were Acarapis-positive by PCR assay which were sequenced to identify species. Each sequence showed 92.6-99.3% homology with reference sequences. Based on the homology, the number of colonies infected with A. dorsalis was 32 which showed the highest infection rate among the 3 species, while the number of colonies infected with A. externus and A. woodi was 9 and 1, respectively. However, none of the Acarapis mites were morphologically detected. This result could be explained that all apiaries in the survey used acaricides against bee mites such as Varroa destructor and Tropilaelaps clareae which also affect against Acarapis mites. Based on this study, it is highly probable that Acarapis mites as well as Varroa and Tropilaelaps could be prevalent in Korean apiaries.