Stock composition of northern neotropical honey bees: mitotype and morphotype diversity in Mexico (Hymenoptera: Apidae)

International audienceAbstractThe stock of honey bees in the northern neotropics is likely a composite of European and African lineages, but the genetic makeup of most populations in this region has remained unstudied. We analyzed the genetic composition of honey bees across temperate and tropical regions of Mexico using mitochondrial and morphometric analyses. The results showed that honey bees from Mexico are descendent almost in similar proportion from matrilines of African and European origins. However, morphometrics indicate that most colonies are the result of extensive introgressive hybridization with Africanized bees. While large-scale displacement of European honey bees seems to have occurred in the tropical regions, higher frequencies of colonies with a mixed range of African-European markers were identified in the temperate areas. Our results suggest that the outcome of the hybridization between Africanized and European honey bees in Mexico has been significantly associated with climate

The Integrative Taxonomic Approach Reveals Host Specific Species in an Encyrtid Parasitoid Species Complex

Integrated taxonomy uses evidence from a number of different character types to delimit species and other natural groupings. While this approach has been advocated recently, and should be of particular utility in the case of diminutive insect parasitoids, there are relatively few examples of its application in these taxa. Here, we use an integrated framework to delimit independent lineages in Encyrtus sasakii (Hymenoptera: Chalcidoidea: Encyrtidae), a parasitoid morphospecies previously considered a host generalist. Sequence variation at the DNA barcode (cytochrome c oxidase I, COI) and nuclear 28S rDNA loci were compared to morphometric recordings and mating compatibility tests, among samples of this species complex collected from its four scale insect hosts, covering a broad geographic range of northern and central China. Our results reveal that Encyrtus sasakii comprises three lineages that, while sharing a similar morphology, are highly divergent at the molecular level. At the barcode locus, the median K2P molecular distance between individuals from three primary populations was found to be 11.3%, well outside the divergence usually observed between Chalcidoidea conspecifics (0.5%). Corroborative evidence that the genetic lineages represent independent species was found from mating tests, where compatibility was observed only within populations, and morphometric analysis, which found that despite apparent morphological homogeneity, populations clustered according to forewing shape. The independent lineages defined by the integrated analysis correspond to the three scale insect hosts, suggesting the presence of host specific cryptic species. The finding of hidden host specificity in this species complex demonstrates the critical role that DNA barcoding will increasingly play in revealing hidden biodiversity in taxa that present difficulties for traditional taxonomic approaches

Diversidad genética y conservación de poblaciones de abejas sin aguijón mesoamericanas : Melipona beecheii y Melipona yucatanica (Apidae : Meliponini) / William de Jesús May Itzá; directores, Mª Pilar de la Rúa Tarín, José Javier G. Quezada Euán.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M. 3898

Eficacia del humo de frutos de Guazuma ulmifolia (Sterculiaceae) y vapores de timol para el control de Varroa destructor infestando abejas africanizadas

The mite Varroa destructor is a scourge in honey bee colonies worldwide. Conventional chemical-based control treatments can contaminate colony products and cause resistance in the parasite. Plant-source compounds are promising alternatives. The effectiveness of smoke from dried Guazuma ulmifolia fruit and vapors from thymol crystals was evaluated in control of V. destructor in colonies of Africanized bees (Apis mellifera) in Yucatan, Mexico. Three treatments were used during a three-week experimental period. In Group 1, colonies were administered five to eight puffs of smoke from dried G. ulmifolia fruits twice a week. In Group 2, they were administered 4-8 g of thymol crystals once a week. Group 3 was a control and received no treatment. Collections of 200 to 300 adult bees from each colony were done prior to treatment (day 0) and after treatment at 7, 14 and 21 d. These were processed to quantify colony infestation levels and treatment efficacy. Overall V. destructor infestation levels in adult bees decreased in all three groups after 21 d, with differences between treatments. Levels were lowest in Group 2, followed by Group 1 and the control. Efficacy at the end of the treatments was 41 % in Group 1 and 69% in Group 2. Compared to the control, application of thymol crystals provided the most effective alternative control method against V. destructor. However, regular application of G. ulmifolia fruit smoke also reduced mite infestation levels, and this resource has the advantage of being locally available.Se evaluó la eficacia del humo de los frutos secos de Guazuma ulmifolia y los vapores de timol en el control del ácaro Varroa destructor infestando colonias de abejas africanizadas (Apis mellifera) de Yucatán. Se utilizaron tres tratamientos: Grupo 1 (G1), las colonias de abejas recibieron 5 a 8 bocanadas de humo de los frutos secos de G. ulmifolia dos veces por semana, durante un período de tres semanas; Grupo 2 (G2), las colonias recibieron 4-8 g de cristales de timol con tres aplicaciones cada siete días, y Grupo 3 (G3 o grupo control) las colonias no recibieron ningún tratamiento durante las tres semanas del experimento. Se colectaron 200 a 300 abejas adultas de cada colonia previo a la aplicación de los tratamientos (día 0) y a los 7, 14 y 21 días después de las aplicaciones, con la finalidad de determinar los niveles de infestación y eficacia de los tratamientos. Los resultados indican que los niveles de infestación de V. destructor en las abejas adultas disminuyeron al final del experimento (21 días) y fueron estadísticamente diferentes para los tres tratamientos, siendo menor para G2. La eficacia al final de los tratamientos fue de 41 y 69 %, para G1 y G2, respectivamente. Estos resultados corroboran que la aplicación de cristales de timol es una alternativa para el control del ácaro V. destructor en Yucatán, y que la aplicación del humo de los frutos secos de G. ulmifolia reduce los niveles de infestación de este parásito en comparación con las colonias que no recibieron ningún tipo de tratamiento (G3)

Hybridization between European and African-derived honeybee populations (Apis mellifera) at different altitudes in Perú

The current status of admixture between Apis mellifera of African and European origin was studied in populations from different altitudinal regions of Perú. Worker bees from 7 altitudinal regions were analysed by morphometrics and mtDNA RFLPs. Our results showed that the rates of admixture between African-derived and resident European populations have depended on the altitude of the region. Our finding of hybrid colonies at elevations above 2 500 m supports the hypothesis that climate alone may not restrain the northern limit of the distribution of African-derived honeybees in the Americas. We conclude that introgressive hybridization between African and European derived honeybees best explains the current patterns of distribution of morphotypes and mitotypes across the different regions of Peru

Intraspecific variation in the stingless bee Melipona beecheii assessed with PCR-RFLP of the ITS1 ribosomal DNA

In previous works, significant variation in morphometric and molecular characteristics was detected among populations of M. beecheii. Here RFLP tests of the internal transcribed spacer 1 of the ribosomal gene were performed to confirm those results and to evaluate the intraspecific variability within the species. The complete ITS1 region and the flanking regions showed length variation (1720 to 1670) and also three different restriction patterns that allowed differentiation of three groups of colonies with different geographic distribution. Mexican colonies from Yucatán, Campeche and Chiapas, together with one colony from northern Guatemala formed one group, a second was composed of colonies from southern Guatemala, El Salvador and Costa Rica and a third one corresponded to one colony from San Marcos (Guatemala but close to the Mexican border). Such test could be used to characterize locally adapted ecotypes subject to conservation efforts

Estudio de microsatélites en las abejas sin aguijón melipona colimana y m. Beecheii de mesoamérica

In this study, variability of microsatellite loci has been for the first time analyzed in the wild stingless bee Melipona colimana. Data have been compared with those obtained from an insular population of the managed species M. beecheii. Genotyping results in M. colimana demonstrate that microsatellite loci sequences are conserved within the genus Melipona. Population parameters such as number of alleles and heterocigosity values, were not significantly different between the two studied species, both being within the observed range in other Melipona species. Values of the insular M. beecheii population were lower than in previously studied continental populations of the same species, in agreement with the results obtained in other island organisms. Wild M. colimana colonies are susceptible to deforestation effects, so that, we have compared the genetic parameters of colonies from a deforested area with those of a conserved area. Population diversity was not significantly different, may be due to recent environmental perturbations that are not yet reflected in the genetic diversity of these insects.En este estudio, se ha analizado por primera vez la variabilidad de los loci de microsatélites en la especie silvestre de abejas sin aguijón Melipona colimana. Los datos obtenidos se han comparado con los de una población insular de la especie domesticada M. beecheii. Los resultados del genotipado de los individuos de M. colimana, indican que la secuencia de los loci de microsa- télites está conservada dentro del género Melipona. Los parámetros poblacionales estudia- dos (número de alelos y valores de heterocigosi- dad) no mostraron diferencias significativas entre las dos especies estudiadas, estando ambos dentro del rango observado en otras especies del género. Estos valores fueron inferiores en la población insular de M. beecheii con respecto a otras poblaciones continentales de la misma espe- cie analizadas previamente, lo cual coincide con lo observado en estudios previos de otros orga- nismos insulares. La especie silvestre M. colimana es susceptible a los efectos de la deforestación, por ello se han comparado parámetros po- blacionales de colmenas situadas en una zona deforestada y en otra conservada. La diversidad poblacional no ha mostrado diferencias significa- tivas, probablemente debido a que las perturba- ciones del medio estudiado son recientes y aún no se han reflejado en la diversidad genética de estos insectos