T. Eltz;  C. Bause;  K. Hund;  J. J. G. Quezada-Euan; T. Pokorny (2015) Correlates of perfume load in male orchid bees. Chemoecology 25: 193-199. DOI 10.1007/s00049-015-0190-9

Abstract 

Male neotropical orchid bees collect volatile substances from their environment and compose complex, species-specific odour blends in leg pouches. These perfumes are accumulated by the males over time and are exposed during pre-mating display. It has been hypothesized that perfumes are indicators of male genotypic quality and that females chose mates by the quality or intensity of their odour. Because direct experimental proof is lacking, we investigated whether the amount or complexity of male perfumes is related to male (1) size, (2) fluctuating (left–right) asymmetry, or (3) age, traits that are known to be sexually selected in other animals. We measured left and right forewings (cell node distances for 1 and 2, wing wear for 3) of Euglossa dilemma and Euglossa viridissima collected during dry and rainy seasons on the Yucatán peninsula, Mexico (total N = 768). Wing size was not related to the quantity or the complexity of perfume extracts in either species after excluding the effect of season, which positively affected both size and perfume load in E. dilemma. Wing asymmetry had also no effect, except in rainy season E. viridissima, where it was positively (not negatively) correlated with the quantity of perfume. Wing wear, an established age indicator of orchid bees, had the only consistent overall effect, being positively correlated with perfume amount and complexity in both species. This is in agreement with the idea that perfumes are an honest indicator of male survival capacity.

 

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L. A. Medina-Medina, A. G. Hart, F. L.W. Ratnieks (2014) Waste management in the stingless bee Melipona beecheii Bennett (Hymenoptera: Apidae). Sociobiology 61: 428-434

Abstract

Waste management is important in insect societies because waste can be hazardous to adults, brood and food stores. The general organization of waste management and the influence of task partitioning, division of labor and age polyethism on waste processing were studied in three colonies of the tropical American stingless bee Melipona beecheii Bennett in Yucatán, Mexico. Waste generated in the colony (feces, old brood cells, cocoons, dead adults and brood) was collected by workers throughout the nest and taken to specific waste dumps within the nest. During the day, workers based at the waste dumps formed waste pellets, which they directly transferred in 93% of cases, to other workers who  subsequently removed them from the nest. This is an example of task partitioning and is hypothesized to improve nest hygiene as has been found in leafcutting ants, Atta. To investigate division of labor and age polyethism we marked a cohort of 144 emerging workers. Workers forming waste pellets were on average 31.2±6.5 days old (±SD, N= 40, range of 18-45 days). The life span of M. beecheii workers was 49.0±14.0 days (N= 144). There was no difference in the life span of workers who formed (52.2±11.6 days, N= 40) or did not form (49.9±11.5 days, N= 97) waste pellets, suggesting that waste work did not increase mortality. Although waste was probably not hazardous to adults and brood, because the dumps are located outside the brood chamber, its presence inside the nests can attract phorid flies and predators, which can harm the colony.

  

 

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C. Ruiz, W. de J. May-Itzá, J.J.G. Quezada-Euán, P. de La Rúa (2014) Utility of the ITS1 region for phylogenetic analysis in stingless bees: a case study of the endangered Melipona yucatanica Camargo, Moure and Roubik (Apidae: Meliponini). Sociobiology 61: 470-477

 Abstract
The internal transcribed spacers of the ribosomal RNA gene have been recently proposed as an appropriate marker for genetic analysis of the molecular variation of stingless bees. Herein we report the characterization of the complete ITS1 region in two populations (from Mexico and Guatemala) of the endangered Melipona yucatanica Camargo, Moure and Roubik. Phylogenetic analyses showed low genetic variation  between populations but defined a geographic structure with Mexican and Guatemalan specimens forming two well supported clades. Low ITS1 genetic variation found between populations contrasts with high genetic variation found in other markers.  Phylogenetic analysis corroborates the inclusion of M. yucatanica within the subgenus  Melipona sensu stricto based on previous morphological studies. The results highlight  the utility of the ITS1 for the characterization of stingless bee populations.

 

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JO Macías-Macías, JJG Quezada-Euán, JM Tapia-Gonzalez, F Contreras-Escareño (2014) Nesting sites, nest density and spatial distribution of Melipona colimana Ayala (Hymenoptera: Apidae: Meliponini) in two highland zones of Western, Mexico. Sociobiology 61(4): 423-427

Abstract

Melipona colimana Ayala is endemic to the temperate forests of western Mexico and may be in conservation risk due to forest exploitation. Differences between the density of nests, nesting sites and spatial distribution in two places with different levels of human disturbance were established. A preserved (P) and a disturbed area (D) were identified: the forest had not been exploited for more than 18 years in the P zone, while there had been recent forest exploitation of D zone in less than two years. It was determined that nesting sites, nest density and the number of potential nest sites were predominant in the P zone. In total, 27 of 30 colonies were found on oak trees (Quercus laurina) with a diameter at breast height of 183.4 ± 34.21 cm which shows a close relationship of this bee species with this type of tree. A positive correlation between the DBH of the nesting sites in relation to the trees with nests and the presence of cavities was found. The nests are distributed in the form of aggregates in P and D zones (R = 0.31 and 0.39) with a density of 0.17 haˉ¹ and 0.04 haˉ¹ colonies respectively. Forestry exploitation seems to be affecting wild populations since the trees that bees use as nesting sites are destroyed in D zone.

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Proyecto: Evaluación de la eficacia de los frutos secos del pixoy (Guazuma ulmifolia) y cirstales de timol en el control del ácaro Varroa destructor en Yucatán

Responsable técnico

Dr William May Itzá

Colaborador:
Dr Luis Medina Medina

PROYECTO CONVOCATORIA CIENCIA BÁSICA CONACYT 2014

Clave 237532: Cambio Climático y polinizadores: efecto del incremento térmico sobre la estabilidad del desarrollo e indicadores de aptitud biológica en abejas tropicales de México (Hymenoptera: Apidae)

RESPONSABLE TECNICO
DR JOSE JAVIER QUEZADA EUAN
Colaboradores:
Dr Luis Medina Medina
Dr William May Itza
M en C Humberto Moo Valle
Professor Robert J Paxton

RESUMEN

Las abejas (Hymenoptera: Apoidea: Anthophila) son los principales polinizadores de los ecosistemas. Sin embargo, existen pocos estudios sobre el efecto del cambio en el régimen de temperaturas global sobre la sobrevivencia y distribución de abejas mismos que se han centrado principalmente en la abeja melífera  (Apis mellifera) y sus ecotipos Europeos y de clima templado. No obstante, la abeja melífera representa un caso especial de las casi 20,000 especies de abejas a nivel mundial ya que presenta homotermia activa. En contraste, la mayoría de las especies eusociales, incluidas las abejas sin aguijón de distribución exclusivamente tropical, funcionan como organismos hectotermos. En México, en las regiones tropicales predomina la abeja A. mellifera africanizada, pero no existe información de la tolerancia de ecotipos tropicales de esta especie a estrés térmico. Por otra parte, Meliponini es un grupo ampliamente diverso en los trópicos y subtrópicos de nuestro país, constituyendo los polinizadores más importantes de estos ecosistemas. La apicultura y meliponicultura en México son actividades con fuerte tradición que representan importantes ingresos económicos para el país y para un gran número de familias campesinas además de tener un valor cultural para las etnias indígenas por lo que su conservación debe ser parte de las prioridades del rescate de polinizadores.  En este proyecto se propone evaluar la tolerancia de estos importantes insectos a las variaciones térmicas, el efecto sobre la estabilidad del desarrollo, cambios en la conducta y la capacidad reproductiva de individuos producidos bajo regímenes de incremento térmico mismos que pueden afectar la capacidad de sobreviencia y viabilidad de las especies y de los ecosistemas que de ellas dependen.

Quezada-Euán JJG; May-Itzá W de J; Montejo E; Moo-Valle H (2015) Isometric worker size variation in relation to individual foraging preference and seasonal colony growth in stingless bees. Insectes Sociaux 62: 73-80.

Abstract

Isometric worker size variation has been found in various species of stingless bees but the adaptive value of this phenomenon is little understood. We studied intra-colony worker size variation in Melipona in relation to individual foraging preference and colony growth in periods of resource abundance and scarcity. We found significant forager size differences across colonies. In spite of this, intra-colony size of foragers collecting different resources was highly similar, suggesting that foraging preferences and flexibility are size constrained. On the other hand, inter-colony forager size was associated with parameters of colony growth, albeit differently, depending on the season. Our results suggest that isometric forager size may reflect the state of food storage, and thus, colony development in stingless bees. It seems that stingless bee communities respond to seasonal abundance and scarcity with variable cycles of individual colony growth and reduction of reserves that may explain the asynchronous reproduction of colonies, spanning years in these insects.

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