ABSTRACT Tropical forests are three-dimensional with the presence of numerous micro-environments formed by horizontal and vertical gradients. Such micro-environments can affect the nesting preference of organisms, including the trap-nesting Hymenoptera. Bees and wasps are key elements in ecosystems and are considered as sensitive to environmental changes, and trap-nests sampling methodology is widely used in their ecological and conservation studies. However, many uncertainties remain about nesting site preferences. From this perspective, our aim is to assess the diversity descriptors of trap-nesting Hymenoptera in different micro-environments. The sampling was conducted on three micro-environments (canopy, understory and treefall gaps) replicated on ten permanent plots within a Brazilian Atlantic forest hotspot. In each micro-environment, we installed trap-nest stations made by a set of twenty bamboo artificial nests. We found 762 brood cells from ten wasp and five bee species. The rarefaction curves indicate the lower species richness in understory stations, while treefall gaps and canopy stations were not significantly different. We analyzed abundance, mortality and parasitism rates using generalized linear models, but only abundance varies significantly among micro-environments. Our data indicates that trap-nesting Hymenoptera prefer to nest in micro-environments with higher exposure of sunlight. Canopy and treefall gap assemblages are consistently more abundant and diverse than understory probably due the higher temperature and lower humidity. On the other hand, mortality, parasitism rates, and the species composition were similar among environments. Our hypothesis is that the species composition was not affected as these species have a foraging range that encompasses nearby micro-environments.

Abstract Sphecodini are a clade of obligatory parasitic Halictinae, comprising 332 species and five genera worldwide. Recently, Sphecodes Latreille was considered polyphyletic according to the results of a molecular phylogeny. Morphological analysis of Neotropical groups revealed groups of species in Sphecodes s.l. that can be recognized at genus level to improve the classification of the tribe. The main objective of this study is to review the generic classification of Sphecodini, with emphasis on Neotropical groups. I propose Austrosphecodes Michener as a separate genus from Sphecodes s.s. and describe a new genus, Melissocleptis gen. nov. for eight known species. Both genera comprise most of the Neotropical species. Nesosphecodes depressus sp. nov. is described for Brazil and a revised diagnosis for Nesosphecodes Engel is given to accommodate this new species and to include data on male terminalia. A revised key for the genera from the Western Hemisphere is provided.

Abstract Trachypus Klug is a Neotropical genus of crabronid wasps comprising 31 ground-nesting species. Its species can be solitary or communal, and two diet ranges are known: they can forage on several bee subfamilies and wasps; or can be specialists on stingless bees. Natural history observations are scarce nowadays but are essential to contextualize ecological and evolutionary studies. Here we report new records and give biological notes for Trachypus elongatus (Fabricius, 1804), Trachypus taschenbergiRubio-Espina, 1975, and Trachypus varius (Taschenberg, 1875). Observations and samplings were carried out twice a month, during one year in the city of Curitiba, southern Brazil. Besides field observations, circular statistics were used to analyze seasonality. All species nest in sloped soil and are solitary. Trachypus elongatus and T. taschenbergi were active during most of the year with marked seasonality in the late spring and early summer. Both species were observed hunting only stingless bees, with T. elongatus specialized on Trigona spinipes (Fabricius, 1793), and T. taschenbergi specialized on Paratrigona subnuda Moure, 1947 drones. Trachypus varius was observed only in January and one female was recorded foraging on a Paratrigona subnuda worker. Our observations provide additional data for understanding the biology of bee-hunting wasps, and this is the first study to bring information for T. taschenbergi and T. varius. Our data corroborate that some species of the genus Trachypus are specialized on stingless bees.

Abstract The introduction of species is an important global threat to native ecosystems and yet little is known about invasion risks of non-native bees. Moreover, urbanization is increasing rapidly around the world with impact on the bee fauna. The city of Curitiba (Brazil) could be considered a model system for studies under this scope, with historical samplings and monitoring programs since the 1940s. This paper aims to quantify the current ecological impact of the non-native bee species present in Curitiba by using an integrative measure of impact and to define their current population status by classifying them into a unified framework for biological invasions. Ten sites were actively sampled in the metropolitan area of Curitiba during ten months. In addition to Apis mellifera Linnaeus, 1758, we found two others non-native species, Anthidium manicatum (Linnaeus, 1758) and Melipona scutellaris Latreille, 1811. None of them changed the native bee community structure, but they got different values of impact due to their ranges and abundances. While the honeybee is a known invasive species, A. manicatum was also considered invasive and has persisted in the city since the 1940s, interacting with the non-native plant Leonurus japonicus Houtt. M. scutellaris, a cultivated stingless bee species, had its first record for the city and fits the casual non-native category. We suggest monitoring the non-native bee species and actions centered on beekeepers to avoid future illegal introductions. The honey production or hobby interest on stingless bees can offer additional obstacles for species conservation when decoupled of scientific knowledge.

ABSTRACT The Augochlora clade includes four genera: Augochlora Smith, Augochlorella Sandhouse, Ceratalictus Moure, and Pereirapis Moure. This is one of the richest and most widespread groups of Augochlorini bees. There are about 150 species, which occur from Argentina to Canada. The species of Augochlora clade are considered solitary to facultatively social, except Ceratalictus for which nothing is known. Wood nesting behavior arose once in the clade, in Augochlora sensu strictu. The objective of this study is to describe four new species and to present a revised phylogenetic analysis of the Augochlora clade for the placement of these species. The morphological matrix comprised 77 characters and 42 terminals, and resulted in two most parsimonious trees. The monophyly of the Augochlora clade is corroborated. Ceratalictus and Pereirapis are considered as sister groups and Ceratalictus inflexus sp. nov. came as sister to other species of Ceratalictus. Augochlora and Augochlorella are monophyletic and sister groups. Both extant subgenera of Augochlora were corroborated as monophyletic. Augochlorella comis is considered as sister group to the rest of Augochlorella species. All Augochlorella new species described belong to the Augochlorella ephyra group. Augochlorella kelliae sp. nov. is phylogenetically related to Augochlorella una. Augochlorella procliva sp. nov. and Augochlorella mavricera sp. nov. constitute a clade with Augochlorella acarinata. Including the new species, Augochlorella has 19 species and Ceratalictus 11 species. A revised key for species of Augochlorella and Ceratalictus is also presented in the Supplementary Information.

Abstract Cavity-nesting bees are enigmatic because they are difficult to observe in the wild, hence trap-nests (man-made cavities) provide the means by which these bees may be studied. Trap-nests is an efficient methodology to study these bees and are common worldwide. These traps have been used for a variety of reasons, including inventories, to examine pollen load, to study habitat disturbance, and bee conservation. However Neotropical trap-nesting bees’ taxonomy and biology are still poorly known and here we provide a review about these subjects. We searched for trap-nest bee studies in the Neotropical Region using Google Scholar and ISI Web of Science at any time in the past to December 2017. We found 109 independent studies, most of which were from Brazil (87 studies), followed by Argentina (10 studies), and other countries had fewer than five studies each. A total of 140 species, 24 genera, 10 tribes and three subfamilies were reported in trap-nests. Nest architecture was described for only 49 species. Taxonomy is only well-known for 14 genera, somewhat known for seven and is essentially unavailable for three genera. Construction material, closing plug and cell shape are similar among species in the same tribes and genera. Vestibular and intercalary cells, and the preliminary plug are variable, even at the specific level. Apinae is the most studied group with available data for all genera recorded in trap-nests. Colletinae is the least-studied group and nothing is known for their nesting biology. Megachilinae is intermediate, with some studies of taxonomy and nesting. We suggest that further trap-nest studies should provide more detailed information on nest architecture and construction materials, including explicit mention of structures that are absent. All Neotropical bees need more taxonomic studies, but some, such as Hylaeus and Megachile, require more attention since Hylaeus is essentially unknown and Megachile is very common on trap-nests.

Abstract Seasonal fluctuations in the abundance of orchid bees have already been reported. The variations in population dynamics may be expected to occur in more predictable and pronounced manners in environments with a clear distinction between rainy and dry seasons, where climatic variables are regarded to be good predictors of populational patterns. The main goal of this paper is to investigate the seasonality of males of orchid bees in fragments of Seasonal Semideciduous Forest in southern Brazil. Data comprise bait samples from five one-year periods on four forest fragments. The seasonality of species abundance was tested with circular statistics. Results suggest two phenological patterns, one for Eufriesea violacea (Blanchard), Eulaema nigrita Lepeletier and Euglossa cordata (Linnaeus), whose abundances are concentrated in late spring and early-middle summer and another for Euglossa fimbriata Moure with a tendency to be collected in middle-late summer and early autumn. These patterns are discussed, as well the possible driven factors, (i) the species life cycle and nesting behavior, (ii) synchrony with resource, and (iii) climate. We can postulate an important impact of climate change in local euglossine assemblage due to the small populations and marked seasonality.

ABSTRACT Paroxystoglossa is a solitary, ground-nesting bee genus. It was revised in 1960 and currently includes nine species from Argentina, Brazil and Paraguay. The objectives of this contribution are to provide a morphological phylogeny for the group and to describe two new species: P. levigata n.sp. and P. mourella n.sp. Paroxystoglossa is monophyletic and three species groups are recognized, jocasta species group: (P. mourella n.sp., (P. brachycera, (P. jocasta, P. barbata))), transversa species group: (P. transversa, P. levigata n.sp.), and crossotos species group: (P. mimetica, (P. crossotos, P. seabrai, (P. andromache, P. spiloptera))). The crossotos and transversa species groups were considered as sister groups. Interestingly Paroxystoglossa species have very similar male genital capsules an uncommon pattern among Augochlorini genera. The species groups have a widely redundant distribution indicating replication events in southeastern South America. An updated, illustrated key for species identification is also presented.

Orchid bees are increasingly applied on Neotropical biomonitoring and bioindication studies due to the relative easiness of sampling and identification when compared to other bee groups. A considerable number of orchid bee community studies have been adopting baited traps as a sampling method, especially for replication purposes. However, the trap attributes are variable, and hitherto no evaluation of different designs was carried out. Here, five attributes of baited traps were tested: trap volume, number of entrance holes, presence of landing platform, kind of landing platform, and fixation content. We use Mann-Whitney tests to access differences in richness and abundance capture rates for each trap design. We found that volume, number of entrance holes, and fixation content do not influence orchid bees capture. However, the design without landing platforms had a significantly higher capture rate for richness when compared with sanded landing platforms. On the other hand, analyzing the kind of landing platform, we detected a significantly higher richness and abundance for the trap with landing platforms glued with sand. Despite the fact that the effects of different designs tested here were very punctual, we consider that results from samples taken with different baited trap designs are comparable. Some adjustments on trap design can be done according to the particularities of future studies.

A Mata Atlântica é um dos ambientes mais ricos e ameaçados do mundo, o que deveria ter estimulado em muito o estudo e a conservação do Bioma, mas a fauna de Hymenoptera permanece ainda relativamente pouco conhecida. Em especial, a fauna de abelhas da floresta ombrófila densa é pouco estudada em comparação à fauna das áreas abertas brasileiras. O projeto temático "Biodiversidade de Hymenoptera e Isoptera: riqueza e diversidade ao longo de um gradiente latitudinal na Mata Atlântica - a floresta úmida do leste do Brasil", integrante do Programa Biota-Fapesp, foi idealizado com o objetivo de catalogar térmitas, formigas e famílias selecionadas de vespas ao longo da Mata Atlântica, disponibilizando dados que permitam melhor embasar a conservação deste bioma. O protocolo de amostragem aplicada para a coleta de himenópteros (excluindo as formigas) empregou armadilhas Malaise, pratos-armadilha de cor amarela e esforço similar na varredura de vegetação ao longo de 17 localidades selecionadas, representando um gradiente de quase 20° de latitude na Mata Atlântica, dos Estados da Paraíba até Santa Catarina. Este protocolo foi definido para otimizar a coleta de vespas, sendo as abelhas um produto secundário da amostragem (levantamentos de abelhas em geral utilizam captura em flores ao longo das estações do ano). No entanto, devido à escala regional do projeto e ao grande esforço de amostragem, uma expressiva quantidade de abelhas foi coletada durante o projeto, incluindo novos registros de abelhas para a Mata Atlântica. Foi amostrado um total de 797 espécimes distribuídos em 105 espécies de abelhas; o grupo de abelhas mais rico e abundante foi Meliponina. Uma análise de correspondência "destendenciada" ('detrended correspondence analysis') aplicada à uma matriz de presença ou ausência de Meliponina revela a relativamente fraca influência do gradiente latitudinal na composição das assembléias de abelhas de Mata Atlântica. Uma listagem das espécies amostradas por localidade, com suas freqüências relativas, é apresentada e discutida.

The Atlantic Forest is one of the most rich and endangered natural environments in the world. It is expected then that this situation would have encouraged the study and conservation of this biome; the Atlantic forest Hymenoptera fauna, however, remains virtually unknown. The bee fauna, for instance, is less studied than that of the Brazilian open areas. The overall ignorance on most of the Atlantic Forest insect faunas based the elaboration of the project "Biodiversity of Hymenoptera and Isoptera: richness and diversity along a latitudinal gradient in the Atlantic Forest - the humid eastern forest of Brazil", within the Biota-Fapesp Program, that aimed to catalog the termites, ants and several wasp families along the Atlantic forest and to publish data that could contribute to the biome conservation. Similar sampling protocols were applied for wasp surveys: the same number of Malaise and pan traps and similar effort on vegetation swapping, along 17 selected localities, representing a gradient of almost 20° of latitude in evergreen pristine Atlantic Forest, from Paraíba to Santa Catarina Brazilian states. These protocols were defined to optimize the collecting of wasps; bees represented a 'secondary product' of the sampling protocol. A sum of 797 specimens representing 105 bee species was sampled; the richest and more abundant bee taxon was the Meliponina. Unfortunately the applied sampling method does not afford comparisons among Atlantic Forest bee assemblages with those of other biomes. The detrended correspondence analysis using only the relative frequencies of Meliponina species revealed a weak correspondence of the stingless bee assemblages' composition with the latitudinal gradient. Despite that, the sampled taxa are possibly restricted to the Atlantic forest and additional data on their distribution deserves to be published. A complete checklist of the sampled bees, their relative frequencies, and the localities where they were recorded is presented and discussed.