Melipona Beecheii Research Articles

Variable patterns of intraspecific sexual size dimorphism and allometry in three species of eusocial corbiculate bees

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.

Effect of Three Entomopathogenic Fungi on Three Species of Stingless Bees (Hymenoptera: Apidae) Under Laboratory Conditions.

Development of alternative strategies for pest control with reduced effect on beneficial organisms is a priority given the increasing global loss of biodiversity. Biological control with entomopathogenic fungi arises as a viable option to control insect pests. However, few studies have focused on the consequences of using these organisms on pollinators other than the honey bee ( Apis mellifera L.) or bumble bees ( Bombus spp). We evaluated the pathogenicity of commercial formulations of three widely used entomopathogenic fungi, Metarhizium anisopliae (Metschnikoff) Sorokin, Beauveria bassiana Vuillemin, and Isaria fumosorosea (Wize), to three species of stingless bees: Tetragonisca angustula Latreille, Scaptotrigona mexicana Guérin-Meneville, and Melipona beecheii Bennett. Bioassays consisted of exposing groups of bees to the recommended field concentration of each fungus using a microspray tower under laboratory conditions. Susceptibility to fungi varied greatly among species . Isaria fumosorosea (strain Ifu-lu 01) and the two formulations of B. bassiana (Bea-TNK and BotanicGard) caused <30.3% mortality in all bee species. Metarhizium anisopliae (Meta-TNK and strain Ma-lu 01) was highly active against T. angustula (94.2% mortality) and moderately active against M. beecheii (53.0% mortality) and S. mexicana (38.9% mortality). Though our laboratory-derived results suggest a moderate to high impact of these entomopathogenic fungi on stingless bees, further field studies are required to support this finding.

Efecto del hongo Trichoderma harzianum sobre las abejas sin aguijón Scaptotrigona mexicana, Melipona beecheii, y la abeja melífera Apis mellifera (Hymenoptera: Apidae)

Toxicity of the Trichoderma harzianum-based fungicide Bioben® was evaluated in three species of bees and Anastrepha ludens, in the Soconusco region, Chiapas, Mexico, under laboratory conditions. Mortality in Scaptotrigona mexicana and Apis mellifera were slightly higher in the exposed groups than in control groups, contrary to Melipona beecheii and A. ludens.

Physicochemical Properties of Melipona beecheii Honey of the Yucatan Peninsula

&lt;p&gt;The knowledge regarding the physicochemical characteristics of the honey produced by stingless bees is still limited, mainly due to the high diversity of the floral resources and the low production that is inherent to these species. This manuscript describes the physicochemical characterization of 27 honey samples produced by &lt;em&gt;Melipona beecheii, &lt;/em&gt;from the Yucatan Peninsula, Mexico. The objective of this study was to contribute to the establishment of standards for quality control. The following parameters were evaluated in the honey samples: reducing sugars, moisture content, acidity, pH, hydroxymethylfurfural (HMF), ash, soluble solids, formol index, proline and color. Most of physico-chemical parameters fulfilled the quality criteria established by the International Legislation for Apis honey, with the exception of moisture content, which presented higher values; for that, the results indicate that the international standard procedures are not completing adequate for all the parameters analyzed on &lt;em&gt;Apis mellifera&lt;/em&gt; honey and therefore is need establish a suitable standard of quality control for honey from &lt;em&gt;Melipona&lt;/em&gt;.&lt;em&gt; &lt;/em&gt;&lt;/p&gt;

Electrophoresis characterisation of protein as a method to establish the entomological origin of stingless bee honeys

Increasing production of stingless-bee honey and the prospect of broader marker for natural and organic products indicate the need to establish parameters to determinate the entomological origin and authenticity of honey. In this research, honeys of Apis mellifera, Melipona beecheii and Trigona spp. were collected in Yucatan, Mexico. Stingless-bee honeys contained more water and less total sugars and reducing sugars. SDS–PAGE patterns show distinctive bands for each kind of honey. The SDS–PAGE pattern of A. mellifera proteins honey showed three bands with molecular weights between 10.2 and 74.8kDa, there were five proteins bands in M. beecheii honey with molecular weights between 6.1 and 97.0kDa and nine for Trigona spp. proteins between 9.3 and 86.7kDa. Conventional physicochemical parameters along with electrophoresis profiles of stingless-bee honeys proteins could be an alternative for determination of entomological origin.

Stingless Bee Honeys from Costa Rica Exhibit Antimicrobial Activity Against Antibiotic-resistant Clinical Isolates

The antimicrobial resistance boosted the development of alternative wound healing therapies. A successful example is Medihoney®. To our knowledge, this is the first report of minimum inhibitory concentration (MIC) assays of Meliponini honeys against antibiotic-resistant isolates of Staphylococcus aureus and Pseudomonas aeruginosa coming from infected hospital patients in comparison to Medihoney®. The samples under study belonged to the Tetragonisca angustula (n = 36) and Melipona beecheii (n = 21) species. 64 % of the T. angustula and 10 % of the M. beecheii honeys inhibited all the antibiotic-resistant bacteria. Medihoney® was active against every strain tested with exception of a P. aeruginosa isolate. Costa Rican T. angustula honeys can be selected according to their broad-spectrum antimicrobial activity. Moreover, such selection can render MICs similar to Medihoney® in order to carry on further research and development towards a novel antimicrobial topical therapy for burn and wound healing.

The antioxidant capacity and immunomodulatory activity of stingless bee honeys proceeding from Costa Rica

Objective: Medihoney® is considered up to date the only antioxidant therapy specifically approved by the United States Food and Drug Administration (FDA) for wound healing. This is the first study that evaluates the antioxidant capacity and immunomodulatory activity of stingless bee honeys in comparison to Medihoney®. The goal of this study was to evaluate in vitro the potentials of Meliponini honey from Costa Rica as an antioxidant wound dressing agent. Materials and Methods: A total of fifty-seven honeys belonging to the Tetragonisca angustula (n = 36) and Melipona beecheii (n = 21) species were studied. Following tests were carried out: screening of radical scavenging activity by the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, superoxide anion radical scavenging assay, inhibition of xanthine oxidase (XO), total phenolic content by the Folin-Ciocalteu reagent, and the oxygen radical absorbance capacity (ORAC) assay. Furthermore, the effect of honey over reactive oxygen species (ROS) produced by human polymorphonuclear leucocytes (PMNL) was evaluated using luminol and a Cypridina luciferin analog as luminescence probes. Results: The positive correlation between the total phenolic content and the ORAC value reported herein, suggests that the antioxidant capacities of the stingless bee honeys examined are given in a major grade to their phenolic constituents. According to present results, the in vitro immunomodulatory activities are explained mainly due to the radical scavenging effect and to the XO inhibition. Both mechanisms may play a role in the impairment of the inflammatory process and the promotion of redox homeostasis. Conclusion: The T.angustula honeys showed antioxidant capacities not statistically different to Medihoney®. In addition, their radical scavenging activity over ROS produced by human PMNLs and inhibition of XO justify their ethnopharmacological use as a wound dressing and further research towards novel wound-healing developments.

Waste Management in the Stingless Bee Melipona beecheii Bennett (Hymenoptera: Apidae)

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 Yucatan, 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.

A Critical View of Colony Losses in Managed Mayan Honey-Making Bees (Apidae: Meliponini) in the Heart of Zona Maya

This research considered native Mayan stingless bees, Melipona beecheii, with special attention to decrease in their managed colonies. From a total of 155 beekeepers located in 60 communities, 58 were randomly selected to survey in 2011. Their experience ranged from less than one to 50 years, and initial colonies from one to 100. Both structured and open interviews were conducted. Participants generally reported they believed bees were obtaining less food, which could produce colony loss. The present and a previous survey in the Zona Maya show colony loss averages 4–5% each year. In this study, during an average of 10 years, 27 beekeepers lost none, 9 lost all, and the remainder lost 44% of their colonies. Further analysis revealed colony loss had no association with relative habitat disturbance, presumed Africanized honey bee abundance, or beekeeping experience. However, those initially with more colonies in a meliponary lost them at a greater rate, indicating competition for food. Initial colony number was near 11, but currently is near 4 per meliponary. Little colony propagation (husbandry) was the norm until recently, when initiatives including meliponiculture workshops stimulated more husbandry. Twenty-six percent of beekeepers had less than one year experience and they began meliponaries using wild colonies. Because established meliponicultors were found to very seldom rely on new wild colonies, increased husbandry efforts are necessary to offset natural mortality of managed colonies. Five meliponicultors increased their colonies over 300% in two years (40 to 123 colonies), whereas a 34% loss in nine years (480 to 206 colonies) was found among the individuals randomly surveyed.

Physico-chemical properties of honeys produced by two stingless bee species - &lt;i&gt;Trigona carbonaria&lt;/i&gt; and &lt;i&gt;Melipona Beecheii&lt;/i&gt; in South-Eastern Nigeria

Tropical honeybees pollinate arable, plantation and wild crops. They also produce honey, which is the most harvested bee product. While apiculture is being practised by few people in Nigeria, meliponiculture which is the practise of keeping stingless bees for production of honey is hardly practiced. This study therefore assessed the physico-chemical properties of honeys produced by two stingless honeybee species, namely Trigona carbonaria and Melipona beecheii found in south-eastern Nigeria. Stinglessbees honey samples were analysed in the laboratory to determine their physico-chemical properties. The results obtained showed that specific gravity and pH were 1.40 and 3.97 for Trigona carbonaria and 1.45 and 4.26 for Melipona beecheii . The values of the moisture, protein and ash contents were 25.43%, 1.29% and 0.45% for Trigona carbonaria and 26.51%, 0.93%, a for Melipona beecheii. Vitamin A content of Trigona carbonaria and Melipona beecheii honey samples were 12.0mg/100g and 11.95mg/100g respectively. Calcium (Ca), phosphorus (P) and sodium (Na) contents were 25.43%, 0.76%, and 12.67% for Trigona carbonaria honey and 26.51%, 1.03% and 11.96% for Melipona beecheii .The fructose, glucose, reducing sugar, higher sugar, sucrose and calorific value contents of Trigona carbonaria honey were 37.25%, 31.64%, 68.89%, 1.50%, 1.20%, 398.88kj/g respectively while for Melipona beecheii, the values were 38.19%, 31.02%, 69.21%, 1.55%, 1.60% and 398.68% respectively. The Ttest results of the physico-chemical properties of the two honey samples studied showed no significant differences (p<0.05) in (a) physical properties especially specific gravity and pH, (b) proximate compositions (moisture, protein and ash) and (c) vitamin A levels for the two honey samples. However, significant differences were observed in phosphorus, sodium, fructose and glucose contents of Trigona carbonaria and Melipona beecheii honeys respectively. Sodium and glucose levels were higher in Trigona carbonaria honey while phosphorus and fructose levels were higher in Melipona beecheii honey respectively.

Antibacterial properties of honey produced by Melipona beecheii and Apis mellifera against foodborn microorganisms

The aim of this study was to determine the antibacterial activity in vitro of Melipona and Apis honey against various foodborne microorganisms. The results of qualitative test showed that Melipona honey inhibited both Staphylococcus aureus ATCC25923 and H08M06 strains and both Escherichia coli ATCC35922 and H12K06 strains. Apis honey inhibited both E. coli ATCC35922 and H12K06 strains and S. aureus ATCC25923 strain. Minimum inhibitory concentrations of Melipona honey (5–16%, w/v) were lower than those of Apis honey (15–31%, w/v). This study demonstrated that the antibacterial potency of Melipona honey could be a new alternative for controlling foodborne illness.

Colony pollen reserves affect body size, sperm production and sexual development in males of the stingless bee Melipona beecheii

The production of male sexual offspring by social insect colonies is often strongly seasonal or resource-dependent. In stingless bees, males are produced in smaller numbers under conditions of low colony food reserves; whether such males are negatively affected in traits related to reproductive success is not known. We compared body size, sperm production and sexual maturity in Melipona beecheii males reared with experimentally supplemented or reduced pollen reserves, but with otherwise equal numbers of workers and equal quantities of honey reserves. We also studied the same traits in males collected from non-manipulated colonies with pollen reserves intermediate between the supplemented or reduced groups but with more workers and honey reserves. Males reared under experimentally reduced pollen reserves had significantly smaller bodies and lower sperm counts compared to those reared in colonies with experimentally supplemented pollen reserves. There was also a significantly positive relationship between the number of sperm and body size in males across all colony treatments. The maximum number of sperm in seminal vesicles was recorded 2 days later in males from colonies with reduced pollen compared to males from colonies with supplementary pollen. Males from non-manipulated colonies were intermediate in size, sperm count and speed of maturation. Our study documents for the first time the existence of large size variation in males of stingless bees that is related with the amount of pollen reserves in their natal colony. We conclude that a colony’s pollen reserves have a major impact on male body size, sperm production and speed of sexual maturity in this stingless bee, which may be the case in other social insects. Stingless bees are a good model system to study the balance between colony-level selection and individual-level selection on male sexually selected traits such as body size.

Morphometric and genetic analyses differentiate Mesoamerican populations of the endangered stingless bee Melipona beecheii (Hymenoptera: Meliponidae) and support their conservation as two separate units

Phenotypic and molecular differences were previously found in populations of the endangered stingless bee Melipona beecheii from two extremes of its geographic range. In this study we combine the use of morphometric and molecular tools, with the aim of investigating patterns of phenotypic and molecular variation in populations across Mesoamerica. Morphometric analyses showed that bees from Mexico have significantly smaller body size compared with populations from Central America, forming two separated groups. Bayesian analysis of the ITS1 spacer of the ribosomal gene also showed the existence of two clusters: one composed by the Mexican populations, and another in which the Central American ones assembled (Guatemala, El Salvador, Nicaragua and Costa Rica). The combined results confirm the presence of two taxonomic units: one distributed in southern Mexico (ranging from the Yucatan peninsula to the north of Guatemala), and a Central American unit found from the southern part of Guatemala down to Costa Rica. These units should be considered separately under conservation programs and therefore, human assisted colony exchange between them should be avoided.

Comparative temperature tolerance in stingless bee species from tropical highlands and lowlands of Mexico and implications for their conservation (Hymenoptera: Apidae: Meliponini)

The objective of this study was to evaluate the temperature sensitivity of three stingless bee species, one from the tropical highland transition Neartic-Neotropical region (Melipona colimana) and two from the tropical lowland regions (Melipona beecheii and Scaptotrigona hellwegeri) of Mexico. The changes in thoracic temperature, behavior, and mortality rate of workers and pupae of the three species submitted to control high and low temperatures were assessed. Workers of highland M. colimana regurgitated water and fanned their wings when submitted to high temperatures, a behavior reported here for the first time in a stingless bee. M. colimana consumed syrup and increased its thoracic temperature in response to cold environment. Workers and pupae of M. colimana experienced lower mortality rates than M. beecheii and S. hellwegeri. The results of this study showed the tolerance of M. colimana to a wider temperature range, possibly as a response to extreme conditions in its native environment. The implications of thermal susceptibility differences for the conservation of highland and lowland stingless bees are discussed.

Geometric morphometrics of the wing as a tool for assigning genetic lineages and geographic origin to Melipona beecheii (Hymenoptera: Meliponini)

The stingless bee Melipona beecheii presents great variability and is considered a complex of species. In order to better understand this species complex, we need to evaluate its diversity and develop methods that allow geographic traceability of the populations. Here we present a fast, efficient, and inexpensive means to accomplish this using geometric morphometrics of wings. We collected samples from Mexico, Guatemala, El Salvador, Nicaragua, and Costa Rica and we were able to correctly assign 87.1% of the colonies to their sampling sites and 92.4% to their haplotype. We propose that geometric morphometrics of the wing could be used as a first step analysis leaving the more expensive molecular analysis only to doubtful cases.

Workers Make the Queens in Melipona Bees: Identification of Geraniol as a Caste Determining Compound from Labial Glands of Nurse Bees

Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the two-locus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.

Virgin queen execution in the stingless beeMelipona beecheii: The sign stimulus for worker attacks

Stingless bees produce considerable numbers of virgin queens over the year, most of which are superfluous and get executed by the workers. Nothing is known yet about the sign stimulus that releases the worker attacks. In the present study we investigated the queen execution process in Melipona beecheii and found in both behavioral observations and experiments with caged living virgin queens that workers are not attracted to them from a distance by means of volatile chemicals. Furthermore, worker aggression, which is obvious towards virgin queens that run through the nest excitedly with their abdomen enlarged and the wings beating, was lowered to almost zero when we made the queens behavior-less by experimentally killing them. Our results clearly show that the sign stimulus for releasing the execution behavior in Melipona beecheii workers is not a chemical stimulus but the virgin queens' conspicuous behavior, which, we hypothesize, could act as a direct measure of their fitness.

Intraspecific variation in the stingless beeMelipona beecheiiassessed 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 Yucatan, 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.

Extinction of Melipona beecheii and traditional beekeeping in the Yucatán peninsula

Rearing of the ‘xunan-kab’ bee (Melipona beecheii) had been practised widely by the Mayans of the Yucatán peninsula long before arrival of the Spanish in the New World, and had been a culturally and economically important activity in that region. Melipona beecheii is kept almost exclusively in traditional log hives. Beekeepers using this bee, from the Mayan zone in Quintana Roo state, Mexico, testify to a 93% decrease in hives during the past one-quarter century. Despite concern that stingless bee keeping is going extinct, there were scant data to examine direct impact of competition from feral African Apis mellifera, deforestation, hurricane damage and lack of instruction and incentive for new stingless bee keepers. We therefore made a survey of beekeepers constituting 20% of the largest traditional beekeeping group in the Americas. These data combined with our field studies, taken over 24 years, suggest that bees are threatened both by environmental changes and by inappropriate management and conservation efforts. Overharvest and failure to transfer colonies to hives or divide them are serious impediments. The major tactics to confront these problems are presented.

Caste ontogeny and the distribution of reproductive cells on the combs of Melipona beecheii (Apidae: Meliponini)

The duration of the development phases of workers, males and gynes was studied in Melipona beecheii, an economically important stingless bee species in southern Mexico. We also determined if gynes and male cells were distributed in clusters on the combs as in other Melipona where laying workers exist. The results showed that the total length of development for the workers was 52.72 ± 1.28 days. In the case of the gynes and males, it was 50.80 (± 1.52) and 53.43 (± 1.12) days, respectively. We found that clustering of male cells in M. beecheii was an uncommon occurrence. We suggest that the main factor explaining the reduced frequency of male cell clusters is that males are not worker-produced in this species, compared to other species of Melipona in which males are worker-produced. Factors related to pollen availability could determine the presence of clustered males in some colonies of this species. stingless bees / Melipona / caste ontogeny / drone production / gyne production