Apidologie最新文献

Tetrapedia amplitarsis is an oil-collecting solitary bee that nests in pre-existing cavities and differs from the other species of the genus in several biological aspects, as nest architecture and phenology. The aim of this study is to present detailed information on its nesting biology. Monthly field sampling was conducted from December 2011 to November 2013 using trap-nests in the Serra do Japi, Jundiaí, São Paulo, Brazil. Thirty nests were sampled, in which 168 brood cells were built. The nests consisted of molded cells in urn shape, made with a mixture of sandy material and floral oil, in linear series with horizontal orientation. Completed nests had one to 14 brood cells. Most nesting activities occurred in the hot/wet season, and the offspring emerged in the cold/dry season. The offspring time development ranged from 24 to 316 days, suggesting a univoltine life cycle but with the possibility of the occurrence of a second generation. The sex ratio was significantly female-biased (2.62♀:1♂). Unknown causes and fratricide were the main factors of mortality. Dermestes sp, microlepidoptera, and Anthrax oedipus were the natural enemies associated with the nests. Our results highlight a different Tetrapedia bee, for which many biological aspects are yet to be studied.

Social interactions with heterospecifics can yield important insights into the flexibility of behaviour and the role of learning in communication. Recently, the honeybee dance, a unique symbolic communication system to communicate positions in space, has been shown to involve learning. We asked if this communication system could potentially be learned by members of a species not normally using this communication system, the bumblebee(Bombus terrestris)—indicating that learning might have been at the origins of dance communication. We used mixed-species colonies of bumblebees and honeybees (Apis millefera) to investigate how the readiness to first establish contact with dancers might develop in uninformed bumblebee foragers. Over a month of observations, we recorded and classified a series of behavioural patterns in newly emerged honeybees introduced into queenright bumblebee colonies. A small subset of the introduced honeybees was able to establish in the nests and displayed their typical behavioural patterns, including homing, dance communication, trophallaxis, and social grooming. Remarkably, grooming and trophallaxis were also displayed to heterospecifics, and bumblebees accepted both, including food offered through trophallaxis, even though this behaviour is not normally used by bumblebees. However, bumblebees never attended honeybees’ waggle dances. Our results contribute to insights about bee social behaviour and cognition by providing a fascinating example of the adaptive use and modification of innate behaviour.

The quality of the queen is crucial for the survival and growth of honey bee colonies. There have been studies related to raising queens with excellent performance since the invention of artificial queen rearing technologies. However, relatively few studies have been undertaken that evaluate the relationship between queen quality and queen morphology and the expression level of reproduction-related genes using different-aged brood in artificial queen rearing practices of Eastern honey bees (Apis cerana). Therefore, we transferred eggs, 1-day-old larvae, 2-day-old larvae, and 3-day-old larvae to queen cells to rear queens until the queen emerged. We measured 12 indicators (the acceptance rate, birth weight, length, caliber and maximum diameter of queen cells, thorax length, width and weight, head width, wing length and width, and number of ovarian tubes). Moreover, the relative expression levels of Hexamerin, Vitellogenin, and Transferrin were measured using fat bodies and ovaries dissected from the newly emerged virgin queens. The results showed that queens reared from eggs exhibited the best morphological indexes and occupied the most abundant reproductive related gene expression level. Parameter values for queen from 1-day-old larvae were significantly higher than those for queens from 2-day-old larvae and 3-day-old larvae, and there was no significant difference between values for queens from 2-day-old larvae and 3-day-old larvae in most data, except for the relative gene expression. In conclusion, as the age of the brood increased, the quality of the queen bees declined. Rearing queens from fertilized eggs are far more likely to yield a better outcome for queen performance and colony function. This study provides data support for raising high-quality queens of Apis cerana, which would be benefit for the protection and better utilization of our native honey bee species.

Despite the significant contribution of stingless bees to pollination and conservation of the environment, information on their effectiveness as pollinators is insufficient. Therefore, we tested their effectiveness using watermelon, which is one of the most economically significant global food crops in terms of production volume and production value. Our study aimed at determining how bee body size, visitation rate, and bee-flower size matching ratio affect pollen deposition. We measured pollen deposition in combination with the morphometrics of 30 bees each and measurements of 30 corresponding flowers they visited. We calculated the bee-flower size matching ratio, the relationship between the bee size, and the flower measurement to gauge the effectiveness of each bee species on pollen deposition and distribution among the three watermelon stigmatic lobes. Our findings elaborate on how the different sizes of various bee parts majorly impacted the amount of pollen deposited. Besides, the number of visits, probing time, and bee behavior when handling the flower also played a role. Bees with a size matching ratio approaching 1 deposited more pollen on a single visit. However, pollen distribution highly depended on the number of visits. Among the stingless bee species, Meliponula ferruginea was the best performer. Though the honey bee species Apis mellifera was the best pollen depositor, its performance was almost similar to that of M. ferruginea. In fact, upon a single flower visit, M. ferruginea performed better than A. mellifera. Based on our findings, it can be concluded that stingless bees, particularly M. ferruginea, are effective pollinators of watermelon flowers. Furthermore, traits like probing time, multiple visits, or frequent visitation are not enough to gauge pollinator effectiveness, but there is also a need to include other traits like the size matching ratio between the bee body and flower head.

Nectar composition is an important driver of insect attractiveness. Although bumblebees prefer sucrose-rich nectar, they were found to be the main pollinators of Gentiana lutea, whose nectar is low on sucrose. Therefore, we tested the hypothesis that bumblebees are attracted to the amino acids proline and β-alanine, which are both naturally occurring at high concentrations in the nectar of G. lutea. We analysed the solution consumption and survival of Bombus terrestris L. (Hymenoptera: Apidae) workers fed with artificial nectars enriched with proline, β-alanine or both, at natural and twice the natural concentrations. We found that consumption of nectar enriched with proline at twice the natural concentration was strongly positively correlated with bumblebee weight. However, when adjusting for individual weight, we found that this solution was the least consumed, suggesting the presence of a regulatory mechanism of proline intake to reduce negative effects on survival. We did not find any direct effect of β-alanine on consumption, although our findings suggest a potential interplay between proline and β-alanine in the regulation of proline intake. Bumblebee survival was not affected by any nectar composition. These results suggest that the high visitation rate to flowers of G. lutea by bumblebees observed in natural populations can be partially related to its nectar amino acidic composition, and that protein and non-protein amino acids can affect pollinator preference and foraging behaviour.

In the coming decades, the human population will grow and demand more food. Therefore, agricultural practices are expected to be intensified. Among these practices is pesticide application. However, pesticides threaten bees and, thus, crop pollination, ultimately jeopardizing our own food security. This dilemma makes precisely quantifying the magnitude of these threats urgent, so we can improve our agricultural management practices. By conducting a systematic review followed by a meta-analysis, we estimated the effect sizes of pesticide application on bees and their crop pollination service. Our results show that pesticides reduce bee survival almost five times. Even when bees survive, sublethal effects can impair crop pollination. The consequences for bee communities and their crop pollination service might not be immediately evident but can be magnified in the long-term. Finally, we conclude that conserving the vegetation surrounding crops and minimizing pesticide use are key to protecting bees and ensuring crop pollination. Moreover, the adoption of integrated pest management (IPM) protocols can ultimately contribute to solving this problem and achieving UN’s sustainable Development Goal 2 (Zero Hunger).

Plebeia is a taxonomically complex genus of stingless bees characterized by remarkable interspecific morphological similarity. On the other hand, cytogenetic data have been useful to resolve taxonomic uncertainties and to infer the diversification processes. Therefore, the goal of this study was to provide a karyotypic analyses in five nominal taxa of Plebeia from northeastern Brazil: P. droryana Friese (Természetrajzi Füzetek kiadja a Magyar nemzeti Muzeum 23:381–394, 1900), P. cf. mosquito Smith 1863, Plebeia aff. droryana 1, Plebeia aff. droryana 2, and Plebeia aff. fravocincta based on traditional and molecular cytogenetic methods to test their applicability in cytotaxonomy and to understand the karyoevolutionary processes in these bees. All species shared a chromosomal number of 2n = 34, except for some individuals of Plebeia aff. flavocincta that presented up to two small and heterochromatic B chromosomes. Species-specific karyotype formulae were observed while the heterochromatin segments were mainly distributed on short arms and pericentromeric regions of most chromosomes, including subtle C-banding differences in each species. The 18S rDNA sites were terminally located on pair 3 of P. droryana, P. cf. mosquito, Plebeia aff. droryana 2, and Plebeia aff. droryana 1, and on the first metacentric pair in Plebeia aff. flavocincta. These data reinforced the efficiency of cytogenetics as an informative tool to discriminate Plebeia species. The present data suggest that structural rearrangements such as inversions and duplications/deletions of heterochromatin and ribosomal clusters are the main drivers of karyotypic evolution in Plebeia.