Pollen diet diversity across bee lineages varies with lifestyle rather than colony size.

The shift to a pollen diet and the evolution of more highly organized societies, i.e., eusocial, were key milestones in bee diversification over their evolutionary history, culminating in a high dependence on feeding broods with a large variety of floral resources. Here, we hypothesized that obligatory eusocial bees have a wider diet diversity than their relatives with solitary lifestyles, and this would be related to colony size. To test both hypotheses, we surveyed diet breadth data (palynological analysis) based on the Shannon-Wiener index (H') for 85 bee taxa. We also obtained colony size for 47 eusocial bee species. These data were examined using phylogenetic comparative methods. The results support the generalist strategy as a derived trait for the bee taxa evaluated here. The dietary diversity of eusocial bees (H': 2.1, on average) was 67.5% higher than that of noneusocial bees (H': 1.21, on average). There was, however, no relationship between diet breadth and colony size, indicating that smaller colonies can harvest a pollen variety as diverse as larger colonies. Taken together, these results provide new insights into the impact of lifestyle on the diversity of collected pollen. Furthermore, this work sheds light on an advantage of living in more highly structured societies irrespective of the size of the colony.

Survivorship and food consumption of immatures and adults of Apis mellifera and Scaptotrigona bipunctata exposed to genetically modified eucalyptus pollen.

Eucalyptus comprises the largest planted area of cultivated production forest in Brazil. Genetic modification (GM) of eucalyptus can provide additional characteristics for increasing productivity and protecting wood yield, as well as potentially altering fiber for a diversity of industrial uses. However, prior to releasing a new GM plant, risk assessments studies with non-target organisms must be undertaken. Bees are prominent biological models since they play an important role in varied ecosystems, including for Eucalyptus pollination. The main goal of this study was to evaluate whether a novel event (Eucalyptus 751K032), which carries the cp4-epsps gene that encodes the protein CP4-EPSPS and nptII gene that encodes the protein NPTII, might adversely affect honey bees (Apis mellifera) and stingless bees (Scaptotrigona bipunctata). The experiments were performed in southern Brazil, as follows: (i) larvae and adults were separately investigated, (ii) three or four different pollen diets were offered to bees, depending on larval or adult status, and (iii) two biological attributes, i.e., survivorship of larvae and adults and food intake by adults were evaluated. The diets were prepared with pollen from GM Eucalyptus 751K032; pollen from conventional Eucalyptus clone FGN-K, multifloral pollen or pure larval food. The insecticide dimethoate was used to evaluate the sensitivity of bees to toxic substances. Datasets were analyzed with Chi-square test, survival curves and repeated measures ANOVA. Results indicated no evidence of adverse effects of Eucalyptus pollen 751K032 on either honey bees or stingless bees assessed here. Therefore, the main findings suggest that the novel event may be considered harmless to these organisms since neither survivorship nor food consumption by bees were affected by it.

Data standardization of plant-pollinator interactions.

BACKGROUND: Animal pollination is an important ecosystem function and service, ensuring both the integrity of natural systems and human well-being. Although many knowledge shortfalls remain, some high-quality data sets on biological interactions are now available. The development and adoption of standards for biodiversity data and metadata has promoted great advances in biological data sharing and aggregation, supporting large-scale studies and science-based public policies. However, these standards are currently not suitable to fully support interaction data sharing. RESULTS: Here we present a vocabulary of terms and a data model for sharing plant-pollinator interactions data based on the Darwin Core standard. The vocabulary introduces 48 new terms targeting several aspects of plant-pollinator interactions and can be used to capture information from different approaches and scales. Additionally, we provide solutions for data serialization using RDF, XML, and DwC-Archives and recommendations of existing controlled vocabularies for some of the terms. Our contribution supports open access to standardized data on plant-pollinator interactions. CONCLUSIONS: The adoption of the vocabulary would facilitate data sharing to support studies ranging from the spatial and temporal distribution of interactions to the taxonomic, phenological, functional, and phylogenetic aspects of plant-pollinator interactions. We expect to fill data and knowledge gaps, thus further enabling scientific research on the ecology and evolution of plant-pollinator communities, biodiversity conservation, ecosystem services, and the development of public policies. The proposed data model is flexible and can be adapted for sharing other types of interactions data by developing discipline-specific vocabularies of terms.

Factors Affecting the Composition and Succession of Beetles in Exposed Pig Carcasses in Southern Brazil.

Coleoptera is one of the largest taxon among animals and exhibits diverse eating habits. When associated with decaying corpses, beetles can be of great value in estimating the postmortem interval. In order to consolidate a useful database for the forensic field, it is necessary to study the entomological fauna associated with the carcasses in different geographical regions since the diversity of insects varies according to the biogeoclimate zone. Thus, this study aimed to assess the influence of environmental and ecological factors on the composition and succession of beetles associated with pig carcasses exposed in southern Brazil. Collections were carried out during the hot/dry and cold/wet seasons. A total of 415 specimens belonging to 18 Coleoptera families were sampled. The highest total abundance (n = 329) and diversity (n = 44 taxa) were recorded in the cold/wet season, corresponding to approximately 80% of the total sampled from the two seasons. Dermestidae (26.7%) was the family most abundantly sampled. Regarding eating habits, in an increasing order of importance were necrophagous (43.3%), predator (31.6%), and omnivorous (0.05%). In the hot/dry season, there was no faunal succession. In the cold/wet season, the succession was more associated with differences in abundance than to the presence or absence of a specific taxon by decomposition stage. Considering all the factors analyzed in the current study, three species of beetles, Dermestes maculatus DeGeer (Dermestidae), Euspilotus azureus (Sahlberg, 1823) (Histeridae), and Oxelytrum discicolle Brullé, 1840 (Silphidae), could be identified as being of the greatest forensic relevance in this biogeoclimatic zone.

Queens become workers: pesticides alter caste differentiation in bees.

Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies.

Monogamy in large bee societies: a stingless paradox.

High genetic diversity is important for the functioning of large insect societies. Across the social Hymenoptera (ants, bees, and wasps), species with the largest colonies tend to have a high colony-level genetic diversity resulting from multiple queens (polygyny) or queens that mate with multiple males (polyandry). Here we studied the genetic structure of Trigona spinipes, a stingless bee species with colonies an order of magnitude larger than those of polyandrous honeybees. Genotypes of adult workers and pupae from 43 nests distributed across three Brazilian biomes showed that T. spinipes colonies are usually headed by one singly mated queen. Apart from revealing a notable exception from the general incidence of high genetic diversity in large insect societies, our results reinforce previous findings suggesting the absence of polyandry in stingless bees and provide evidence against the sperm limitation hypothesis for the evolution of polyandry. Stingless bee species with large colonies, such as T. spinipes, thus seem promising study models to unravel alternative mechanisms to increase genetic diversity within colonies or understand the adaptive value of low genetic diversity in large insect societies.