Cyclopogon is a large Neotropical orchid genus pollinated by halictid bees that offers nectar as a reward. In a recent phylogenetic tree, Brachystele guayanensis emerged nested within Cyclopogon and was transferred to that genus. The hypothesis for this study was that C. guayanensis would show similar floral biology to Cyclopogon, although distinctive in its small, congested white flowers. Data on floral biology, pollinators, micromorphology, histochemistry, and nectar sugar composition of C. guayanensis from samples from the the Distrito Federal, Brazil were gathered. C. guayanensis is pollinated by at least four species of bees belonging to the genera Exomalopsis, Nomada, Tetrapedia (Apidae), and Dialictus (Halictidae) foraging for nectar. Nectar is produced in visually imperceptible quantities by papillae on the inner surface of the labellum; similar papillae occur in other species of Cyclopogon but C. guayanensis nectar is hexose dominant (< 10

ABSTRACT Aim Insect brood parasites (i.e., cleptoparasites), like cuckoo bees, typically attack hosts within specific lineages, but seem to be less constrained by the biogeographical movements of their hosts compared to obligate parasites. Cuckoo bees depend on stable host populations, being particularly sensitive to environmental changes and thus valuable bioindicators of the bee community health. We here test the congruence between the biogeographical history of cuckoo oil bees and their oil bee hosts. Location The Americas. Taxon Bees (Hymenoptera, Apidae). Methods Using phylogenomic and Sanger sequence data, we present new time‐calibrated phylogenies for cuckoo oil bees in the ericrocidine line and their oil bee hosts, Centris and Epicharis. We estimate their ancestral ranges using six historical biogeographical models on a set of 100 trees, randomly sampled from the posterior distribution of phylogenies in each group, thus accounting for uncertainties in divergence time estimates and model selection. Results The origin of the hosts stem in the Cretaceous precedes the origin of their cleptoparasite's stem in the Palaeocene. Cleptoparasite and host crown origins were synchronous in the Eocene, and both took place in tropical South America. While the pair Rhathymini‐ Epicharis remained mostly associated within this region, Centris and their cleptoparasites expanded their distribution to other parts of Neotropical and Nearctic regions in independent range expansions events. In all cases, host range shifts preceded the cleptoparasite shifts. Main Conclusion The biogeographical history of cleptoparasitic oil bees and oil‐collecting hosts is generally congruent in time and space. Events of range expansion mainly occurred in the more species‐rich lineages of cleptoparasites. Range shifts in cleptoparasites followed the distribution of their hosts and coincided with the distribution of oil‐producing plants visited by the host bees. Our results broaden our understanding of the complex biogeography of interacting partners and on how changes in host distributions may impact cleptoparasitic bees.

Land-use changes have led to natural habitat loss and fragmentation, favoring the occurrence of dominant bee species in agroecosystems. This has raised concerns on the dominance effects in pollination-dependent crops like passion fruits (Passiflora edulis Sims) in tropical regions. That is because dominant bee species might overlap their foraging time with regular pollinators, potentially impairing crop yield. Our aim was to understand how dominant small bees affect regular pollinators of passion fruit flowers and its implications on crop production for smallholder farmers. We sampled bees on farms cropping yellow passion fruits in the Cerrado, the Brazilian savanna, and established pollination exclusion experiments to evaluate the interacting effects of dominance and bee community composition on crop yield. We observed a low frequency of regular pollinators, while dominant floral visitors were highly abundant. Dominant pollinators highly overlapped their foraging activity with regular pollinators through time. Contrary to our expectations, the dominance of native and non-native bee species did not directly affect the occurrence of regular pollinators nor crop yield. However, we found evidence that exploitative competition may indirectly affect pollination by regular pollinators. Manual and bee pollination combined increased fruit quality, highlighting the potential benefits of diverse pollinator communities for sustainable crop production. Our findings emphasize the need for strategies that can improve the quality and abundance of resources in agroecosystems for regular native pollinators to optimize pollination in passion fruits on smallholder farms and reduce dominance effects caused by small floral-visiting bees.

Most animal-pollinated flowers offer nec-tar or pollen as a reward to their polli-nators.A small fraction,however,have switched to other rewards,such as fatty oils offered in glandular hairs or just be-low the epidermis.This type of reward has evolved in some 150 genera in at least 11 families,including South Ameri-can and African Orchidaceae[1,2].Oil-offering flowers are exploited by a few hundred species of oil-collecting bees in temperate and tropical biomes on all con-tinents except Antarctica[1,2].Oil bees depend obligatorily on floral oil for cell lining and as larval food[3,4],which is why oil collecting usually is confined to female bees.

Recent fieldwork on tropical bees has revealed that males of Ctenoplectrini, Tapinotaspidini, and Tetrapediini collect floral oils, but it remains unknown for which purpose. Observations and chemical tests in Yunnan show that at least 31 species of Dendrobium and two of Galeola orchids have oil hairs on their petals attracting male Ctenoplectra cornuta who collect the secretion in the same way as do females, which however prefer cucurbit flowers. We observed territoriality and mating on flowers and present a filmed copulation sequence during which the male grasps the female’s scutellum with his mandibles and repeatedly brushes her metasomal fringes with his hind legs and her hind scopae with his mid legs. We hypothesize that male Ctenoplectra scent-mark females during mating, which would explain why the males collect floral oils. Mating behavior has so far been documented in but a few dozen solitary bees, and it is for this reason that we here make available the first filmed copulation of any Ctenoplectrini.

Three new species of Tetrapedia Klug, 1810 (Apidae) from Central Brazil are described and illustrated: Tetrapedia marina sp. nov., Tetrapedia tereza sp. nov., and Tetrapedia bruno sp. nov. Additionally, a key to the 22 species of Tetrapedia known from Brazil is provided. The lectotype of T. clypeata Friese is designated to establish the species name.

Stingless bees are major flower visitors in the tropics, but their foraging preferences and behavior are still poorly understood. Studying stingless bee interactions with angiosperms is methodologically challenging due to the high tropical plant diversity and inaccessibility of upper canopy flowers in forested habitats. Pollen DNA metabarcoding offers an opportunity of assessing floral visitation efficiently and was applied here to understand stingless bee floral resources spectra and foraging behavior. We analyzed pollen and honey from nests of three distantly related stingless bee species, with different body size and social behavior: Melipona rufiventris, Scaptotrigona postica and Tetragonisca angustula. Simultaneously, we evaluate the local floristic components through seventeen rapid botanical surveys conducted at different distances from the nests. We discovered a broad set of explored floral sources, with 46.3 plant species per bee species in honey samples and 53.67 in pollen samples. Plant families Myrtaceae, Asteraceae, Euphorbiaceae, Melastomataceae and Malpighiaceae dominated the records, indicating stingless bee preferences for abundant resources that flowers of these families provide in the region. Results also reinforce the preference of stingless bees for forest trees, even if only available at long distances. Our high-resolution results encourage future bee-plant studies using pollen and honey metabarcoding in hyper-diverse tropical environments.

O desconhecimento da biodiversidade representa um dos principais entraves para seu manejo e conservação. Uma série de estudos tem demonstrado a extinção rápida das espécies de abelhas nas áreas urbanas e periurbanas, de modo que o inventário rápido e disseminação do conhecimento das espécies nativas e sua distribuição através de uma metodologia simples, de baixo custo e facilmente replicável, representa uma das metas para evitar que o desconhecimento leve a extinção local e regional das espécies. O objetivo deste trabalho foi realizar e apresentar a efetividade um inventário rápido de 5 semanas, da diversidade de abelhas dos Campos Rupestres da Serrinha do Paranoá - uma área de extrema relevância biológica no Planalto Central do Brasil. Para amostragem das abelhas foi usado basicamente armadilhas passivas como copos armadilhas azuis UV (pan-traps) e garrafas-pet com iscas aromáticas. Foram coletadas 849 abelhas de 90 espécies, sendo 536 abelhas de 78 espécies em pan traps e 314 abelhas de 31 espécies nas armadilhas de garrafas pet. As estimativas de riqueza sugerem ao menos 120 espécies a partir da amostragem com estas técnicas de coleta. Foi observado que as áreas mais altas e com menor proporção de urbanização apresentam maior riqueza de espécies que as áreas destinadas mais alteradas e destinadas a implementação ao Parque Pedra dos Amigos. Comparativamente com estudos realizados no Cerrado, os valores de riqueza são semelhantes, porém o diferencial encontra-se no tempo realizado no presente estudo de somente 5 semanas. É preciso alertar sobre a necessidade de conservação destas áreas únicas do DF, evidenciando à sociedade que a supressão destas áreas levará à extinção local das espécies presentes na serrinha do Paranoá.