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Apis mellifera ruttneri / taxonomy / subspecies / Malta / evolution

Across the globe, wild bees are threatened by ongoing natural habitat loss, risking the maintenance of plant biodiversity and agricultural production. Despite the ecological and economic importance of wild bees and the fact that several species are now managed for pollination services worldwide, little is known about how land use and beekeeping practices jointly influence gene flow. Using stingless bees as a model system, containing wild and managed species that are presumed to be particularly susceptible to habitat degradation, here we examine the main drivers of tropical bee gene flow. We employ a novel landscape genetic approach to analyse data from 135 populations of 17 stingless bee species distributed across diverse tropical biomes within the Americas. Our work has important methodological implications, as we illustrate how a maximum-likelihood approach can be applied in a meta-analysis framework to account for multiple factors, and weight estimates by sample size. In contrast to previously held beliefs, gene flow was not related to body size or deforestation, and isolation by geographic distance (IBD) was significantly affected by management, with managed species exhibiting a weaker IBD than wild ones. Our study thus reveals the critical importance of beekeeping practices in shaping the patterns of genetic differentiation across bee species. Additionally, our results show that many stingless bee species maintain high gene flow across heterogeneous landscapes. We suggest that future efforts to preserve wild tropical bees should focus on regulating beekeeping practices to maintain natural gene flow and enhancing pollinator-friendly habitats, prioritizing species showing a limited dispersal ability.

Mitochondrial genotypes of Africanized honeybees fromBrazil and Uruguay were surveyed by DraI restriction of the COI-COII region. Eleven mitotypes were found, three of which had not previously been described (A28-A30). Out of 775 samples (725 from Brazil, 50 from Uruguay), 197 were A1 and 520 were A4. A1 frequency increases toward the north of Brazil, whereas A4 frequency increases toward the south, a pattern echoing the African distribution. The origin of the A4 and most of the A1 African patterns can be attributed to the introduction of Apis mellifera scutellata into Brazil in 1956. The A29 and A30 patterns have the P1 sequence observed in many Iberian Peninsula samples, which represent the traces of the introductions into Brazil and Uruguay by settlers.

We see today many efforts to quantify biodiversity in different biomes. It is very important then to develop and to apply other methodologies that allow us to assess biodiversity. Here we present an example of application of three tools with this goal. We analyzed two populations of Plebeia remota from two distinct biomes that already showed several differences in morphology and behavior. Based on these differences, it has been suggested that the populations of Cunha and Prudentópolis do not represent a single species. In order to verify the existence or absence of gene flow between these two groups, we characterized the patterns of mtDNA through RFLP, the patterns of wing venation through geometric morphometry, and the cuticular hydrocarbons through gas chromatography-mass spectrometry. We used bees collected in these two locations and also from colonies which have being kept for around 9 years at Sao Paulo University. We found six different haplotypes in these specimens, of which three of them occurred exclusively in the population of Cunha and three only in the Prudentópolis population. The fact that the populations do not share haplotypes suggests no maternal gene flow between them. The two populations were differentiated by the pattern of the wing veins. They also had different mixtures of cuticle hydrocarbons. Furthermore it was shown that the colonies kept at the university did not hybridize. These two groups may constitute different species. We also show here the importance of using other methodologies than traditional taxonomy to assess and understand biodiversity, especially in bees.

-The present work characterized the mitochondrial DNA (mtDNA) of five species of Plebeia (Plebeia droryana, P. emerina, P. remota, P. saiqui and P. sp.) and generate a data set to be used in further populational, phylogenetic, and biogeographic studies. The mtDNA of each species was analyzed using 17 restriction enzymes and restriction maps were built. A high level of interspecific variability was found. The total size of the mtDNA was estimated to be 18500 bp. Through a combination of PCR and examination of restriction fragment length polymorphism, the locations of 14 of the main mitochondrial genes were located on restriction maps. We verified a gene order identical to Apis mellifera.Plebeia / stingless bee / mtDNA / rflp / restriction map

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