Nestmate recognition in the stingless bee Melipona panamica (Apidae, Meliponini)

Summary: Nestmate recognition was studied in the Neotropical stingless bee Melipona panamica, a species in which workers "sneak" their own reproductive eggs into 1 % of brood cells. We manipulated four factors that could influence individual recognition cues: the mother queen, the environment during the immature stage, the environment during the early adult stage, and worker age. We also simulated the action of natural enemies on colonies tested for discrimination of such worker characteristics. All factors that we tested affected responses of the discriminating workers, which could recognize sisters, nieces and unrelated workers. Previous exposure of unrelated callow bees to the odor of the host nest greatly increased chances of acceptance by the host colony. Probability of acceptance decreased, however, with increasing age of introduced bees or increasing disturbance of the host colony. These complexities in patterns of nestmate recognition and nest defense are adequately explained from the standpoint of inclusive fitness of the discriminating workers. Differences in nestmate recognition and worker egg laying among Meliponini are also discussed.     

Landmark orientation during the approach to the nest in the stingless beeTrigona (Tetragonisca) angustula (Apidae,Meliponinae)

Summary We displaced a small nest box containing stingless bees (Trigona (Tetragonisca)angustula) over distances of up to 1.6 meters in different directions and counted the numbers of returning foragers to measure the effects of this manipulation on the homing ability of bees. Bees find it hard to locate the nest box when it was displaced more than about 1 m backwards, forwards or sideways relative to the direction into which the nest entrance pointed. They do not find the nest when its height above ground is changed. The bees use landmarks in the vicinity of the nest to locate it: When the nest box is displaced and landmark positions are changed so that their angular position at the new nest site is the same as at the normal nest position their homing ability is less impaired than it is without changes in landmark positions. Our results show that the bees do not use the nest box itself as a landmark until they have approached the nest position to within about 1 meter with the aid of surrounding landmarks.     

Antibacterial activity of honey from stingless honeybees (Hymenoptera; Apidae; Meliponinae).

The aim of the study was to examine antibacterial activity of the honey of stingless honeybees (Meliponinae). An agar well diffusion assay demonstrated that many honey samples of stingless honeybees inhibited the growth of test strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa; moreover, they exhibited non-peroxide antibacterial activity against those strains. This is the first time that non-peroxide antimicrobial activity of honey from a number of species of stingless honeybees has been demonstrated. These antibacterial activities appear to be powerful, even when compared to those of"manuka honey" from Apinae honeybees.     

Flight activity and colony strength in the stingless bee Melipona bicolor bicolor (Apidae, Meliponinae)

Flight activity of Melipona bicolor bicolor, coming from Cunha (23o05'S, 44o55'W), Atlantic Forest, was studied in ten colonies, and in two periods: from July to September 1993 and from August to September 1995. The colonies were grouped in weak, medium and strong, according to the diameter of the combs, which can provide a good idea of the number of cells built. 855 observations were accomplished for 5 minutes, every half-hour, from 8 to 18 hours. The total number of bees that entered and left the hive and the number of bees that arrived with mud, pollen and resin, besides the number that went out with debris in that period were counted. It was also registered the temperature and the relative humidity of the air. The total external activity, as well as pollen collection, was maximum in the first hours of the morning, mainly in strong colonies. Weak colonies moved their maximum activity approximately to 12 hours. Pollen collection declined gradually, while mud and resin collection rose; removal of debris was greater in the beginning of the morning and in the end of the afternoon. Flight activity increased as relative humidity of the air rose, being optimum for strong colonies in the range between 80%-89%, and for the weakest colonies between 70%-79%. The minimum temperature observed for exit of the bees was 11oC, with optimum temperatures ranging between 17oC and 22oC. The results showed that the general state of the colony influences the different strategies of food collection and that these bees should be adapted to environments of high relative humidity as the Atlantic forest.     

Clustered male production by workers in the stingless bee Melipona subnitida Ducke (Apidae, Meliponinae)

Summary: In stingless bees brood cells are sequentially filled with liquid larval food (mass-provisioning), upon which the queen lays an egg. Thereafter the cell is closed by a worker. This study showed that during these processes workers of Melipona subnitida regularly laid eggs that served as food for the queen. Occasionally cells were oviposited in and immediately closed by a worker. These cells always rendered males. Some of these reproductive workers were seen to lay a trophic egg as well. Cells which were exclusively oviposited in by the physogastric queen gave rise to workers and queens only. In one colony it could be verified that three workers alone, which differed in age by one day, laid 15 male-producing eggs within a period of two successive weeks. Among them the number of ovipositions was positively related to the order in which workers eclosed - the oldest worker laying most eggs - and inversely related to the number of times they closed cells oviposited in exclusively by the queen. Apparently the physogastric queen was not able to stop certain workers from reproducing. We therefore conclude that some workers in M. subnitida temporarily dominated their queens in egg-laying.     

Frugivory by a stingless bee (Hymenoptera: Apidae)

Frugivory is not frequent among bees. Although stingless bees visit aged fruits for pulp, the use of fresh fruits is recorded only for Trigona hypogea Silvestri, a species that does not visit flowers. Here we report the occurrence of frugivory in Trigona amazonensis (Ducke), a flower-visiting stingless bee.     

Brood comb construction by the stingless bees Tetragonula hockingsi and Tetragonula carbonaria

Tetragonula hockingsi and T. carbonaria are two closely related species of Australian stingless bees. The primary species-specific character is the architecture of the brood comb. The brood comb of T. hockingsi is an open lattice comprising clumps of about ten cells that are connected by vertical pillars. In contrast, in T. carbonaria the brood comb is a compact spiral in which all brood cells (except on the margins) are connected by their walls to adjacent cells at the same height. We made detailed observations of the cell construction process in two colonies of each species. From these observations we formed a species-specific hypothesis about the algorithm followed by the bees during cell construction. The two algorithms allowed us to make predictions about the locations of new cells. Both T. hockingsi and T. carbonaria share a preference for constructing new brood cells in the clefts formed by two or three adjacent existing brood cells, but there are differences in detail for other components of the building process. The fundamental difference in the cell construction process of the two species is that for T. hockingsi, when a cluster of cells contains ten cells, the next cell added to the cluster is offset upwards by half a cell length, or, less often, a vertical pillar rather than a new cell is constructed. In T. carbonaria, cell construction is continuous at the comb margin so that there are no gaps between cells. Furthermore, it seems that T. hockingsi only makes use of local knowledge of the brood comb when deciding to place new brood cells, whereas T. carbonaria could make some building decisions based on knowledge of the total structure. We translated the species-specific algorithms into agent-based lattice swarm computer simulations of the cell construction process for the two species. These simulations produced representations of brood combs that are similar to those seen in vivo, suggesting that our biological rules are realistic.     

A new species of Syntretus Foerster (Hymenoptera: Braconidae: Euphorinae), a parasitoid of the stingless bee Trigona carbonaria Smith (Hymenoptera: Apidae: Meliponinae)

A new species of euphorine braconid, Syntretus trigonaphagus sp. nov., is described and illustrated. This is the first Australian Syntretus species to be described and the first record of braconids parasitising Trigona Jurine stingless bees. Egg-laying by adults and emergence of larvae from the host Trigona carbonaria is detailed. A 12S ribosomal rRNA gene fragment was sequenced to confirm the association of larvae and adults of the wasp parasitoid.     

Microsatellite loci for the stingless bee Melipona rufiventris (Hymenoptera: Apidae)

Eight microsatellite primers were developed from ISSR (intersimple sequence repeats) markers for the stingless bee Melipona rufiventris. These primers were tested in 20 M. rufiventris workers, representing a single population from Minas Gerais state. The number of alleles per locus ranged from 2 to 5 (mean = 2.63) and the observed and expected heterozygosity values ranged from 0.00 to 0.44 (mean = 0.20) and from 0.05 to 0.68 (mean = 0.31), respectively. Several loci were also polymorphic in M. quadrifasciata, M. bicolor, M. mandacaia and Partamona helleri and should prove useful in population studies of other stingless bees.     

Melissopalynological analysis of stingless bee (Tetragonula pagdeni) honey in Eastern Thailand

Melissopalynological analysis of 72 Tetragonula pagdeni honey samples, collected from various locations in Chanthaburi (A) and Trat (B) provinces, Eastern Thailand during March 2015, was performed. Overall, 45 pollen types species belonging to 22 plant families were identified. The predominant pollen type was from Nephelium lappaceum and comprised 48.5% of the pollen in honey from location A2 (Pathavee district) and 45.3% in location B1 (AoYai district). The secondary pollen types, Wodyetia bifurcata and Mimosa pudica, accounted for 20.1% and 17.0%, respectively, in location B3 (Nhongsamed district), while Cocos nucifera accounted for 17.2% in location A2. In addition, pollen types of C. nucifera, M. pudica, N. lappaceum, Asystasia gangetica, Amaranthus lividus, Areca catechu, Chromolaena odorata and Durio zibethinus were found in T. pagdeni honey from all sampled locations. Furthermore, in the dearth period, T. pagdeni foraged food (as in pollen was present) from Musa sp., Acacia mangium and various weed species, such as A. gangetica, A. lividus, Ageratum conyzoides, Bidens pilosa, C. odorata, Melampodium divaricatum, Mikania cordata, Merremia umbellata, M. pudica, Pennisetum pedicellarum and Thysanoleana maxima, from within a 500?m radius around the hive to maintain their colonies.     

Ergonomics in stingless bees: changes in intranidal behavior after partial removal of storage pots and honey inMelipona favosa (Hym. Apidae,Meliponinae)

Summary The ergonomics of task allocation in stingless bees was examined in two laboratory colonies ofMelipona favosa containing individually marked workers. Performance of intranidal behavior patterns, brood cell production and the processing and storage of nectar, were studied during a control and a wax-deprived period. Experimental wax deprivation consisted of regular controlled removal of storage pots and their contents. Stored carbohydrate concentration and storage pot mass declined during the wax-deprived period. Behavior was measured by sampling for a complete ethogram at seven intranidal areas.In comparison withApis mellifera, M. favosa appeared to be more sensitive to stress, with a distinct reallocation of effort between tasks. The significant increase under stress of brood production and brood-rearing behavior patterns observed was previously also found inApis. Self-oriented behavior patterns declined under stressed circumstances.Involucrum construction declined in wax-deprivedMelipona colonies. Relatively low rates of walking behavior in general inMelipona suggest a low mean free distance between tasks. These results are of particular interest in relation to the basically different nest structure of stingless bees, e.g. very distinct areas for brood production and the processing and storage of food. This architecture of stingless bee nests appeared to influence strongly their specific responses to wax deprivation.