Stingless Bees Fed on Fermented Soybean-extract-based Diet Had Reduced Lifespan than Pollen-Fed Workers

Nectar and pollen are the basic food resources of stingless bees. The current advance of meliponiculture led to the search for supplementary feeding. Despite little is known about native bee supplementation, several alternative foods have been tested as protein substitutes, with soy being one of the most commonly used. In this study, we compared the effect of a semiartificial soy-based diet versus a natural diet on the longevity of adult worker of Melipona flavolineata Friese and Scaptotrigona aff. postica (Latreille). A total of 200 workers of each species (40 from each colony) were used, of which 100 comprised the control group (consumed honey and pollen) and 100 the experimental group (honey and a semiartificial food based on soybean extract). The workers were divided into groups of 20 individuals confined in MDF boxes not completely enclosed, without a queen, and kept in BOD incubators. Dead bees were counted and removed daily. Kaplan-Meier survival curves were plotted for each species. We found greater longevity in workers who consumed only natural pollen (71 days for M. flavolineata, 78 days for S. aff. postica, in average) compared to those consuming the soy-based diet (62 days for M. flavolineata, 61 days for S. aff. postica, in average). Workers of M. flavolineata that consumed pollen lived nine days more (21.8%) than those fed on the soy-based diet, while S. aff. postica workers lived seven days more (12.7%). As longevity was only slightly reduced, we can recommend a soy-based diet for stingless bees during dearth periods or for supplemental feeding of newly formed colonies

Temporal Memory in Foraging of the Stingless Bee Melipona subnitida (Hymenoptera: Apidae: Meliponini)

Bees feed on nectar and pollen, however these resources are often available to floral visitors during restricted temporal windows. The presence of temporal memory is an advantage, as foragers can save energy by scheduling their flight activity to coincide with peaks of nectar secretion in the flowers or at times of higher sugar concentration in the nectar. Thus, the objectives of this study were (i) to investigate whether Melipona subnitida has temporal memory, and evaluate whether it becomes more accurate over the days, and (ii) to determine whether the behavior of anticipating the offered resource presents intra-individual consistency in the behavior of foragers. The visitation of the bees was high before and during the opening interval of the food resource, but rare after the closing, suggesting that M. subnitida has the ability to memorize the time of availability of the resource, increasing the accuracy over the days, with bees anticipating their visits in relation to the time they discovered the resource, and the opening time of the resource. There was individual consistency in the behavior of food-anticipatory activity, with the presence of bees that consistently anticipated in relation to the opening time of the resource (inspectors) and bees that consistently did not anticipate (reactivated forager) . By anticipating the search for a resource, foragers allow the group to exploit it effectively, as they exploit it in the first hours of its opening, and foragers that never anticipate avoid unnecessary risks of predation and energy expenditure

DECODING COLONY SIZE OF AMAZONIAN STINGLESS BEES THROUGH INTRINSIC PARAMETERS

Stingless bees live in populous colonies that vary in size from a few hundred individuals to tens of thousands, although information on actual colony size is limited. Determining colony sizes using easily measurable biological parameters are important steps to understanding their life histories and ease their utilization and keeping. The objectives of this study were to determine the colony size of five Amazonian stingless bee species (Melipona flavolineata, Melipona fasciculata, Scaptotrigona aff. postica, Frieseomelitta longipes and Plebeia minima), and to identify biological parameters that covary with colony siz

Effect of forager-deposited odors on the intra-patch accuracy of recruitment of the stingless bees Melipona panamica and Partamona peckolti (Apidae, Meliponini)

We show that the stingless bees Melipona panamica and Partamona peckolti have a high precision of intra-patch recruitment that is influenced by forager-deposited odor marks in the field. We trained foragers to a 2.5 M sucrose feeder in the center of an array of five identical feeders (20 cm between feeders) at different distances and directions from the nest and measured the distribution of recruit visitations. In the free-foraging phase foragers could odor mark a filter paper around the experimental feeder, and in the odor-removal phase we substituted it each five minutes by a clean one. Significantly more recruits in both species chose the experimental feeder over the controls in the distance and directional arrays ($P$ $\leq$ 0.034) and odor removal significantly decreased precision of recruitment in both species ($P$ $\leq$ 0.034). Scent marks in both species thus play a significant role in orienting recruits to already known profitable food sources

Worker longevity in an Amazonian Melipona (Apidae, Meliponini) species: effects of season and age at foraging onset

International audienceAbstractWe studied the relationship between worker longevity and the age of foraging onset in the bee Melipona fasciculata, as well as the longevity oscillation in the rainy and dry seasons. Workers that emerged in the rainy season started to forage later and lived at least 50 % longer than foragers from the dry season. In both periods, a higher longevity was observed in workers that started to forage earlier in life but did not forage all days of their careers. We also showed, by using a Weibull model, that workers experienced higher mortalities at older ages in the rainy season, but the same model did not fit with the data from the dry season. This lack of fit in the dry season can be explained by the high mortality of workers that did not start to forage in this season and to other intrinsic factors of the colonies. Thus, the age of foraging onset and internal colonial factors must be considered in studies examining worker longevity in free-foraging colonies in this diverse group of eusocial bees

First Records of Heartbeats via ECG in a Stingless Bee, <i>Melipona flavolineata</i> (Apidae, Meliponini), during Contention Stress Using Isoflurane as an Anesthetic

The hemodynamic activity of Melipona flavolineata workers was evaluated during restraint stress for a period of 30 min. The observed parameters were power variation in the elapsed time, and subsequently, six periods of one second were divided and called A, B, C, D, E and F; in each period, the electrocardiographic parameters were evaluated: spike frequency, amplitude, spike intervals and spike duration. The experiment was carried out with eight worker bees of M. flavolineata, for which electrodes of a nickel–chromium alloy were made. The bees were previously anesthetized with isoflurane and properly contained and fixed in a base for stereotaxis in which the electrode was implanted. All these procedures were performed inside a Faraday cage. The results showed power oscillations during the recording, with the highest energy level being between 300 and 600 s. Spike frequency, spike amplitude, interval between spikes and spike duration parameters underwent changes during the restraint stress period. Thus, the cardiac activity of M. flavolineata can be used as a biomarker and can be used to clarify physiological issues or alterations caused by toxic agents and indicate risk factors for these animals