Microsatellite Marker Discovery in the Stingless Bee Uruçu-Amarela (Melipona rufiventris Group, Hymenoptera, Meliponini) for Population Genetic Analysis.

The species Melipona rufiventris Lepeletier, 1836 is a Brazilian native stingless bee that is part of a species complex known as the 'rufiventris group', making it difficult to distinguish between the different species. Populations in this group are facing a severe decline, leading to the risk of local extinction, and therefore, their conservation should be treated as a major concern. This study describes the first set of tri- and tetranucleotide microsatellite markers, using next-generation sequencing technology for use in the identification of genetic diversity and population structure in the 'rufiventris group'. A total of 16 microsatellite loci displayed polymorphism. Analysis of the whole data set (n = 50) detected 63 alleles in all loci, ranging from 2 to 7 with a mean of 3.9 alleles/locus. A genetic diversity analysis revealed high values for population differentiation estimates (FST = 0.252, RST = 0.317, and DEST = 0.284) between the Atlantic Forest, Cerrado, and Caatinga biomes. An additional evidence for genetic divergence among populations was also found in the 'rufiventris group'; these should be treated as separate conservation units or even as separate species. These microsatellite markers have demonstrated a strong potential for assessing population discrimination in this threatened stingless bee group.

Cytogenetic Analysis and Chromosomal Mapping of Repetitive DNA in Melipona Species (Hymenoptera, Meliponini).

Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chromosomes, and the species of each subgenus share the same characteristics in relation to heterochromatin regions, DAPI/CMA3 fluorophores, and the number and distribution of 18S rDNA sites. Microsatellites were observed only in euchromatin regions, whereas the (TTAGG)6 repeats were found at telomeric sites in both groups. Our data indicate that in addition to the chromosome number, the karyotypes in Melipona could be separated into 2 groups that are characterized by conserved cytogenetic features and patterns that generally are shared by species within each subgenus, which may reflect evolutionary constraints. Our results agree with the morphological separation of the Melipona into 4 subgenera, suggesting that they must be independent evolutionary lineages.

Possible introgression of B chromosomes between bee species (Genus Partamona ).

The origin of supernumerary (B) chromosomes is still a debated topic, with intra- and interspecific origins being the most plausible options. In the bee Partamona helleri, a sequence-characterized amplified region (SCAR) marker being specific to B chromosomes suggested the possibility of interspecific origin. Here, we search for this marker in 3 close relative species and perform DNA sequence comparison between species. The SCAR sequence does not show homology with other sequences in the databases, but does contain an open reading frame with sequence homology with a reverse transcriptase. Dot-blot hybridization using the SCAR marker as a probe confirmed that it is present in B-carrying, but not B-lacking larvae of P. helleri, and indicated its presence in adult individuals of P. cupira and P. criptica. Additionally, PCR amplification of the SCAR marker was successful on genomic DNA obtained from P. helleri and P. rustica larvae carrying B chromosomes, and on genomic DNA obtained from adult individuals of P. cupira, P. criptica and P. rustica. Finally, a comparison of the DNA sequence of the SCAR markers amplified from these 4 species showed very few nucleotide differences between the species. The complete association between B chromosome and SCAR presence and the scarce divergence observed for this DNA sequence between the 4 species analyzed suggest the possibility that this B chromosome has recently been transferred between species through several episodes of interspecific hybridization.

Honey physicochemical properties of three species of the Brazilian Melipona.

Physicochemical analyses were carried out to evaluate 27 samples of honeys from three species of the Brazilian genus Melipona (M. capixaba, M. rufiventris and M. mondury) from Espírito Santo and Minas Gerais States. The parameters water activity (Aw), percentage of soluble solids (Brix %), pH, acidity (meq/Kg) and moisture (%) were evaluated. The honey characteristics obtained from these samples were very similar to the ones from other Melipona species. However, regarding the honey from Apis (honey bee), only the pH values were similar. The low pH value and the high acidity detected in Melipona honey are potential factors for increasing the honey shelf life because they do not provide favorable conditions for the microbial development. On the other hand, the high level of water activity favors the growth of microorganisms, especially yeast, which demands a more careful handled and storage. The observed differences between Melipona and Apis honey reinforce the need for specific quality settings for stingless bee honey.

[Visitation of orchid by Melipona capixaba Moure & Camargo (Hymenoptera: Apidae), bee threatened with extinction]. / Visitação de orquídea por Melipona capixaba Moure & Camargo (Hymenoptera: Apidae), abelha ameaçada de extinção.

The stingless bee Melipona capixaba Moure & Camargo is a species restricted to the Atlantic forest in the Domingos Martins, Conceição do Castelo, Venda Nova do Imigrante and Afonso Cláudio County, in the Espírito Santo State, Brazil. Despite its cological importance as pollinator few studies have examined the ecology and biology of this bee. This note relates a case of the M. capixaba workers carrying pollinarium attached to the scuttellum. The pollinaria were identified as belonging to the orchid subtribe Maxillariinae species possibly of the genus Maxillaria sensu lato or Xylobium.

Visitação de orquídea por Melipona capixaba Moure & Camargo (Hymenoptera: Apidae), abelha ameaçada de extinção / Visitation of orchid by Melipona capixaba Moure & Camargo (Hymenoptera: Apidae), bee threatened with extinction

The stingless bee Melipona capixaba Moure & Camargo is a species restricted to the Atlantic forest in the Domingos Martins, Conceição do Castelo, Venda Nova do Imigrante and Afonso Cláudio County, in the Espírito Santo State, Brazil. Despite its cological importance as pollinator few studies have examined the ecology and biology of this bee. This note relates a case of the M. capixaba workers carrying pollinarium attached to the scuttellum. The pollinaria were identified as belonging to the orchid subtribe Maxillariinae species possibly of the genus Maxillaria sensu lato or Xylobium.

A abelha sem ferrão Melipona capixaba Moure & Camargo é uma espécie restrita à Mata Atlântica nos municípios de Domingos Martins, Conceição do Castelo, Venda Nova do Imigrante e Afonso Cláudio, ES. Apesar de sua importância ecológica como polinizador, poucos estudos têm investigado a biologia e ecologia dessa abelha, popularmente conhecida como uruçu-negra, pé-de-pau, ou uruçu-capixaba. Esta nota relata uma observação de operárias de M. capixaba carregando polinário preso ao escutelo. Os polinários foram identificados como pertencentes a uma espécie da subtribo Maxillariinae e, possivelmente, a um dos gêneros Maxillaria sensu lato ou Xylobium.