Maéva Angélique Techer

Okinawa Institute of Science and Technology | OIST · Ecology and Evolution Unit

Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses and, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epi...

Host switching allows parasites to expand their niches. However, successful switching may require suites of adaptations and also may decrease performance on the old host. As a result, reductions in gene flow accompany many host switches, driving speciation. Because host switches tend to be rapid, it is difficult to study their demographic parameter...

Host switching allows parasites to expand their niches. However, successful switching may require suites of adaptations and may decrease performance on the old host. As a result, reductions in gene flow accompany many host switches, driving speciation. Because host switches tend to be rapid, it is difficult to study them in real time and their demo...

Background The honey bee parasite, Varroa destructor , is a leading cause of honey bee population declines. In addition to being an obligate ectoparasitic mite, Varroa carries several viruses that infect honey bees and act as the proximal cause of colony collapses. Nevertheless, until recently, studies of Varroa have been limited by the paucity of...

The previous genetic characterization of the honeybee population of Mauritius Island (Indian Ocean) revealed an ongoing process of hybridization between the first established African subspecies Apis mellifera unicolor and recently imported European subspecies ( A . m . ligustica , A . m . carnica and A . m . mellifera ). This context offers the rar...

Background The honey bee parasite, Varroa destructor , is the leading cause of global honey bee population declines. In addition to being an obligate ectoparasitic mite, Varroa carries several viruses that infect honey bees and act as the proximal causes of colony collapses. Yet, until recently, the study of Varroa has been limited by the availabil...

Introductory paragraph Host switching allows parasites to expand their niches. However, successful switching may require suites of adaptations and may decrease performance on the old host. As a result, reductions in gene flow accompany many host switches, driving speciation. Because host switches tend to be rapid, it is difficult to study them in r...

The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honey bee (Apis cerana), to the naïve European honey bee (Apis mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honey bee health. Worrying ob...

The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honey bee (Apis cerana), to the naïve European honey bee (A. mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honey bee health. Worrying obse...

The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honeybee (Apis cerana), to the naïve European honeybee (A. mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honeybee health. Worrying observa...

Multispecies host-parasite evolution is common, but how parasites evolve after speciating remains poorly understood. Shared evolutionary history and physiology may propel species along similar evolutionary trajectories whereas pursuing different strategies can reduce competition. We test these scenarios in the economically important association bet...

Through a country-wide survey, the present study aimed at investigating the extent of the spread of Varroa destructor in Nigeria. To this end, a total of 122 Apis mellifera colonies from 13 localities were sampled in regions without previous assessment of the mite. Infestation and prevalence rates were estimated using the soap washing method. Varro...

Multispecies host-parasite evolution is common, but how parasites evolve after speciating remains poorly understood. On one hand, their shared evolutionary history and physiology may propel them along similar evolutionary trajectories. Alternatively, they may pursue different strategies to reduce competition with each other. Here, we test these sce...

With globalization the Western honey bee has become a nearly cosmopolitan species, but it was originally restricted to the Old World. This renowned model of biodiversity has diverged into five evolutionary lineages and several geographic “subspecies.” If Apis mellifera unicolor is indubitably an African subspecies endemic to Madagascar, its relatio...

Sampling effort represented by allele accumulation curves for 14 microsatellite loci in La Réunion, Mauritius, and the Comoros Islands, compared to other insular and continental populations. (A) Overall sampling size scale and (B) comparative lower scale. Only the three largest continental populations of Italy, France, and South Africa are represen...

Mean number of alleles per locus (14 microsatellites) within La Réunion and Mauritius (sites with n ≥ 5). (TIF)

Distribution of honey bee colony sampling sites in Madagascar, and the Seychelles and Mascarenes archipelagos. First line and from left to right: Geographic positions of 127 sampling sites from La Réunion, 31 from Mauritius, and 20 from Rodrigues in the Mascarenes Archipelago. Second line and from left to right: Geographic positions of the 81 sampl...

Distribution of honey bee colony sampling sites in the four islands of the Comoros Archipelago. (TIF)

Coexistence of two genetic clusters and hybrid honey bees in Mauritius (N = 367), based on 14 microsatellite loci. A) STRUCTURE bar plots at K = 2 and 3. Sites are separated by black lines and are ordered from MUS01 to 31. Maternal origin (top) for each individual (evolutionary lineage, A, C, or M) defined by the DraI test on the COI-COII intergeni...

Complete sample database, including sample IDs, location coordinates, mtDNA COI-COII DraI profiles, and multi-locus genotypes determined at 14 microsatellite loci. (XLSX)

Pairwise FST values among sites from Zimbabwe (ZWE), France (FRA), and Italy (ITA) with N ≥ 5, based on 14 microsatellites. After Bonferroni corrections, permutations tests were only significant among French sites (in bold P < 0.000549). Colors as in Table 3. (DOCX)

Pairwise FST values among sites at Mauritius Island with N ≥ 5 based on 14 microsatellites. Statistical significance for the permutation tests after Bonferroni corrections is indicated in bold (P < 0.000476). Colors as in Table 3. (DOCX)

European and African samples are good representative outgroups for native honey bee populations structured using the distribution of mtDNA lineages. A) STRUCTURE bar plots (K = 2 to 5) for 263 honey bee colonies sampled in Africa and Europe, inferred from 14 microsatellite loci. Each vertical line represents the posterior assignment probability of...

Absence of population structure in the 2,050 honey bee colonies sampled from 127 sites at La Réunion, based on 14 microsatellite loci. A) STRUCTURE bar plots at K = 2, B) Average likelihood of runs in STRUCTURE L(K) along with number of clusters (K) for La Réunion. C) ΔK, estimator of the optimal number of clusters (K) according to Evanno et al. (5...

DAPC barplots of the Western honey bee populations from southwest Indian Ocean islands at global scale. DAPC bar plots are presented for K = 3 to 8, based on 4,388 honey bees. (TIF)

Mitochondrial COI-COII intergenic region diversity (based on DraI restriction profiles) and nuclear diversity indices for each SWIO, African, and European sampling site. N: number of colonies per site; NACOI-COII: number of individuals with missing COI-COII data, Nall: mean number of alleles; Hnb and Hobs: unbiased expected and observed heterozygos...

Genetic structure of honey bee populations from islands in the Comoros Archipelago, inferred from 14 loci microsatellites. A) STRUCTURE bar plots from K = 2 to 5. All colonies had haplotypes from the COI-COII intergenic region characteristic of the African evolutionary lineage. B) Average likelihood of runs in STRUCTURE L(K) along with number of K...

A) Average likelihood of runs in STRUCTURE L(K) along with number of K clusters for global STRUCTURE based on 4,388 honey bees Comoros Archipelago (Fig 6). B) ΔK, estimator of the optimal number of clusters (K) according to Evanno et al. (58). (TIF)

Relationship among the different genetic clusters computed using DAPC approach on 4,388 samples of the Western honey bee. Colors of the different clusters correspond to the S10 Fig. (TIF)

The honeybee population of the tropical Reunion Island is a genetic admixture of the Apis mellifera unicolor subspecies, originally described in Madagascar, and of European subspecies, mainly A.m. carnica and A. m. ligustica, regularly imported to the island since the late 19th century. We took advantage of this population to study genetic admixing...

Background The South West Indian Ocean (SWIO) archipelagos and Madagascar constitute a hotspot of biodiversity with a high rate of endemism. In this area, the endemic subspecies A. m. unicolor has been described in Madagascar. It belongs to the African lineage, one of the four described evolutionary lineages in honey bees. Despite a long beekeeping...

The domestication of the western honey bee Apis mellifera and globalization have facilitated the arrival and spread of new parasites and pathogens such as the Varroa mites. Since the ectoparasitic mite Varroa destructor made the host switch to the western honeybee, it has successfully spread almost worldwide and is considered as the most damaging p...

Les îles du Sud-Ouest de l'océan Indien (SOOI) abritent une faune et une flore exceptionnelle et constituent l'un des cinq hotspot de biodiversité les plus importants au monde. L'abeille domestique Apis mellifera occupe divers habitats dans la majorité de ces îles et interagit avec une flore indigène et endémique. Elle est également exploitée par l...

1. In the South-West Indian Ocean, the honeybee Apis mellifera is found on several islands including the Seychelles archipelago. This archipelago is located 1120 km North of Madagascar, where the endemic African subspecies A. m. unicolor occurs. The genetic diversity of the honeybee populations in the Seychelles islands has never been studied, yet...

Apis mellifera unicolor is a tropical honeybee endemic of Madagascar. Comprehensive knowledge about its mitochondrial and nuclear genetic diversity and structuration was our main purpose. Samples of worker bees were collected from 867 colonies in 76 sites in Madagascar and 1 reference population in South Africa. PCR-restriction fragment length poly...

Apis mellifera is present in Rodrigues, an island in the South-West Indian Ocean. The history of the established honeybee population is poorly known, and its biodiversity has never been studied. In this study, maternal origins of A. mellifera in Rodrigues have been assessed with the DraI test and sequencing of the mitochondrial COI-COII region. Nuc...

The islands of the South West of the Indian Ocean are a hotspot of biodiversity with high rates of endemism. Honeybees play a major role in theses insular tropical ecosystems, interacting with indigenous and endemic species but also with exotic and invasive ones. In Madagascar (heart of the hotspot of biodiversity) the honeybee has already been des...

The islands of the South West of the Indian Ocean are a hotspot of biodiversity with high rates of endemism. Honeybees play a major role in theses insular tropical ecosystems, interacting with indigenous and endemic species but also with exotic and invasive species. In Madagascar (heart of the hotspot of biodiversity) the honeybee has already been...