sábado, 26 de noviembre de 2016
miércoles, 2 de noviembre de 2016
Landaverde-González P; Moo-Valle H; Murray T E; Paxton R J; Quezada-Euán J J G; Husemann M (2017) Sympatric lineage divergence in cryptic Neotropical sweat bees (Hymenoptera: Halictidae: Lasioglossum). Organisms Diversity & Evolution 17 (1): 251-265
Given ongoing biodiversity decline, an important concern is that a large fraction of species diversity is not yet documented. Correct delimitation of species remains a challenge, especially for small and morphologically uniform groups such as sweat bees (Halictidae). Here, we applied an integrative taxonomic approach to study diversity within the Neotropical sweat bee subgenus Dialictus (genus Lasioglossum). We used four statistical methods to delimit species based on cytochrome oxidase subunit I gene sequences: Automatic Barcode Gap Discovery (ABGD), two variants of the General Mixed Yule Coalescent (single-threshold (stGMYC) and Bayesian (bGMYC)) and the Refined Single Linkage analysis (RESL). We detected eight principal molecular operational taxonomic units (mOTUs). Subsequently, these lineages were evaluated using ten nuclear microsatellite loci and morphological and ecological analyses. Most mOTUs could be differentiated using microsatellites and morphology (82 % identified correctly), further supporting the status of mOTUs as independent biological units. For the two most widespread mOTUs, we analysed intra-lineage geographic variation using microsatellites but did not detect additional substructuring. We further tested if the lineages showed predictable patterns of co-occurrence and habitat preferences. While we did not find any evidence of preferential association or disassociation between taxa, we detected a slight positive effect of high crop cover favouring the abundance of some lineages. We show that integrated approaches using statistical analysis of DNA barcodes jointly with additional data can provide robust and objective means of delimiting species in morphologically difficult groups.
martes, 11 de octubre de 2016
Hurtado-Burillo M, Jara L, May-Itzá W de J, Quezada-Eúan J J G, Ruiz C, De la Rúa P (2016) A geometric morphometric and microsatellite analyses of Scaptotrigona mexicana and S. pectoralis (Apidae: Meliponini) sheds light on the biodiversity of Mesoamerican stingless bees. J. Ins. Cons. 20 (5): 753-763.
Geometric morphometrics and molecular methods are effective tools to study the variability of stingless bee populations and species that merit protection given their worldwide decline. Based on previous evidence of cryptic lineages within the Scaptotrigona genus, we tested the existence of multiple evolutionary lineages within the species S. mexicana and we investigated the status of S. pectoralis. By analyzing their population structure, we found differences between the Pacific and Atlantic populations of each of these species, although geometric morphometrics of the wing only confirmed these results in S. mexicana. There was a tendency towards enhanced genetic differentiation over larger distances in the Atlantic populations of both species but not in the Pacific populations. These results revealed a pattern of differentiation among evolutionary units and a specific distribution of genetic diversity within these Scaptotrigona species in Mesoamerica, suggesting the need for future taxonomic revisions, as well as activities aimed at management and conservation.
Hurtado-Burillo M, May-Itzá W de J, Quezada-Euán JJG, De la Rúa P, Ruiz C (2017) Multilocus species delimitation in Mesoamerican Scaptotrigona stingless bees (Apidae: Meliponini) supports the existence of cryptic species. Syst Entom. 42 (1): 171-181.
AbstractAccelerating taxonomic knowledge and making accurate species identifications are critically important given the current biodiversity crisis, particularly in biodiversity hotspots such as Mesoamerica. Objective species delimitation that reduces investigator-driven bias is fundamental to the establishment of appropriate conservation strategies, above all in managed species. Previous morphological and molecular studies on three managed stingless bee species of the genus Scaptotrigona distributed in Mexico (S. mexicana, S. pectoralis and S. hellwegeri) suggested that both S. mexicana and S. hellwegeri are cryptic species complexes. Herein we tested species delimitation by analysing sequence information of five markers (two mitochondrial: cox1 and 16S, and three nuclear: ITS1, EF1-α, ArgK) within a Bayesian coalescent framework to test the putative species. We obtained two different hypotheses using a Generalized Mixed Yule Coalescent (GMYC) model: four (cox1) and six (16S) species. After the species validation step with the Bayesian species-delimitation analysis (BPP), we suggest that only S. mexicana is a complex of two species with different distribution (along the Pacific and the Atlantic coasts, respectively). We highly recommend avoiding colony exchange between geographical regions in order to conserve the genetic integrity of both taxa.
PDF Systematic Entomology
lunes, 1 de agosto de 2016
Visitantes Verano de la Investigación Científica Academia Mexicana de Ciencias
Universidad Juárez Autónoma de Tabasco.
Br. Brenda Alfonso Dávila
Br. Sergei Paolo Arévalo Campos
Proyecto: Diagnóstico de enfermedades y parasitosis en abejas melíferas (Apis mellifera).
27 de junio al 12 de agosto.
Tutor: Dr. Wílliam de Jesús May Itzá
domingo, 19 de junio de 2016
Medina RG, Fairbairn DJ, Bustillos A, Moo-Valle H, Medina S, Quezada-Euán J J G (2016) Variable patterns of intraspecific sexual size dimorphism and allometry in three species of eusocial corbiculate bees. Insectes Sociaux 63: 493-500
Sexual size dimorphism (SSD), in which one sex is larger than the other, has remained understudied in social insects, particularly bees. Using weight and linear structural measurements, we quantified the magnitude of SSD and its variation across nests in three species of corbiculate bees, two belonging to the highly eusocial Apini (Apis mellifera) and Meliponini (Melipona beecheii), and one to the primitively eusocial Euglossini (Euglossa viridissima). We asked if similar to most insects, including Hymenoptera, SSD is female-biased in these eusocial species. Contrary to expectations, we found that SSD was moderately male-biased in the two highly eusocial species and slightly male-biased for weight and not significant for linear size in E. viridissima. The possible roles of queen protogyny and reduced brood provisioning by queens in shaping these patterns of SSD are discussed. The allometry of SSD among nests differed among species as well, ranging from hypoallometry in A. mellifera, to isometry in M. beecheii, to hyperallometry in E. viridissima. This variation indicates that the phenotypic response of body size to differing conditions across nests differs both between sexes and among species. The variation detected among the three studied species in both SSD and allometry for SSD precludes any broad generalizations to other corbiculate bees. However, it does suggest that corbiculate bees can provide a new and diverse framework to analyze the effects of social environment on the evolution of animal sexual dimorphism.
Carolina Isabel Cuanalo Romero
Tesis de Maestría: Biología reproductiva y apifauna visitante de la jícama Pachyrhizus erosus (L) Urban: (Fabaceae-Papilionoideae) en Yucatán.
Fecha de examen 7 de junio de 2016.
Asesores: Dr William May Itzá y Dr J Javier Quezada Euán
jueves, 2 de junio de 2016
miércoles, 1 de junio de 2016
jueves, 26 de mayo de 2016
miércoles, 4 de mayo de 2016
Macias Macias J O; Quezada-Euán J J G (2015) Stingless bees in a temperate climate: oviposition behavior and duration of ontogenic development stages in Melipona colimana (Hymenoptera: Meliponini). J. Apicultural Res. 54: 255-259
Melipona colimana is a stingless bee endemic to temperate areas of the Trans-Mexican volcanic belt, where intranest behavior during the provisioning and oviposition process, duration of ontogenic development stages and time of emergence of individuals were determined. It was observed that the dynamics of provisioning and oviposition do not differ substantially from tropical species of the same genus, but ontogenic development in a temperate climate was longer than in a tropical climate, possibly due to lower temperatures in the original habitat of the species. Duration of ontogenic
development of M. colimana individuals is the longest recorded so far among the species of Melipona genus. Worker bees took 55.44 ± 1.09 days to emerge from the cells; males, 57.14 ± 0.94 and gynes, 52.62 ± 0.63, with statistical differences between them (F = 367.72, DF = 2, 395, p < .05). The gynes emerged before workers, and workers before the males. The obtained data can be used to promote the sustainable use of this species in mountains in Mexico.
viernes, 15 de abril de 2016
Gutiérrez E., Ruiz D., Solís T., May-Itzá W. de J., Moo-Valle H., Quezada Euán J.J.G. (2016) Does
larval food affect cuticular profiles and recognition in eusocial bees? a test
on Scaptotrigona gynes (Hymenoptera: Meliponini). Behav Ecol. Sociobiol. 70: 781-789
The relative contributions of heritable and environmentally acquired components of colony odor towards individual recognition are scarcely known in social insects. Larval food may affect cuticular profiles which in turn may serve as cues in the process of elimination of excess gynes characteristic of the eusocial stingless bees. In this study we evaluated the contribution of larval food to cuticular profiles of stingless bee gynes and quantitatively tested if recognition (latency) from workers may be related to gyne chemotype and origin in the species Scaptotrigona pectoralis. Our results showed that the origin of food did not significantly affect the cuticular profiles of gynes, as larvae of the same origin reared on food from different colonies showed similar cuticular profiles at emergence. We suggest that overlapping over floral resources may account for the similarity in cuticular cues derived from food across experimental colonies. Additionally, workers showed similar latency time to first aggression towards gynes irrespectively of their chemotype and origin. Gyne’s mass had no effect on the aggressive response from workers either. We observed that gynes threatened aggressive workers which counteracted further aggression. Our results indicate that in stingless bees cuticular hydrocarbons at emergence seem to have genetic origin and that gyne tolerance seems not related to cuticular chemical profiles. We suggest that cuticular cues may serve as caste labels for the identification of newly emerged gynes after which worker aggression towards them would elicit behavioral indicators of their fitness.
jueves, 17 de marzo de 2016
Tesis de Licenciatura: Diferencias en tamaño y Asimetría Fluctuante en individuos y castas de la abeja sin aguijón Melipona beecheii Benett (Hymenoptera: Apidae: Meliponini)
Fecha de examen 17 de Febrero de 2016
Asesor: Dr J Javier Quezada Euán
jueves, 3 de marzo de 2016
Professor Robert J. Paxton and Alice Segurét estancia del 8 de febrero al 27 de marzo de 2016 para dar inicio al proyecto DFG
Phenotypic plasticity and reproduction-longevity life-history trade-off: investigating the underlying basis in an orchid bee at the cusp of sociality
sábado, 27 de febrero de 2016
UN Report: Pollinators Vital to Our Food Supply Under Threat
Reporte de las Naciones Unidas: Polinizadores vitales para nuestro suministro alimenticio en riesgo
By the numbers
- 20,000 – Number of species of wild bees. There are also some species of butterflies, moths, wasps, beetles, birds, bats and other vertebrates that contribute to pollination.
- 75% – Percentage of the world's food crops that depend at least in part on pollination.
- US$235 billion–US$577 billion – Annual value of global crops directly affected by pollinators.
- 300% -- Increase in volume of agricultural production dependent on animal pollination in the past 50 years.
- Almost 90% -- Percentage of wild flowering plants that depend to some extent on animal pollination.
- 1.6 million tonnes – Annual honey production from the western honeybee.
- 16.5% -- Percentage of vertebrate pollinators threatened with extinction globally.
- +40% – Percentage of invertebrate pollinator species – particularly bees and butterflies – facing extinction