The açaí palm Euterpe oleracea Mart. in the Amazon river delta has seen rapid expansion to meet increased demand for its fruit. This has been achieved by transforming lowland forest habitats (floodplains) into simplified agroforests and intensive plantation in upland areas. As açaí palm makes an important contribution to the economy and food security of local communities, identifying management approaches that support biodiversity and ecosystem processes that underpin fruit production on açaí farms is essential. We compared flower‐visitor communities and açaí fruit production in floodplain forests and upland plantations, across gradients of local management intensity (i.e. açaí density per ha) and surrounding forest cover. The relative contribution of biotic pollination and degree of pollen limitation were assessed using insect exclusion and hand‐pollination experiments. We found that açaí flower visitors are highly diverse (c. 200 distinct taxa) and had variable responses to disturbance. Bee visitation was higher in floodplains and positively related to surrounding forest cover, but other flower visitors, including specialised curculionid beetles, were unresponsive to changes in surrounding forest cover. However, intensive management practices (i.e. high açaí palm densities) in floodplains and uplands had contrasting effects on flower‐visitor communities, with flower‐visitor richness being lower on intensively managed floodplain farms and ant densities being higher on intensive upland farms. Pollination experiments revealed açaí palm to be highly dependent on biotic pollination. Fruit set in open‐pollinated inflorescences was positively related to flower‐visitor richness and specialised curculionid beetle visitation, whereas the presence of ants on inflorescences had a negative effect. Synthesis and applications. Our study shows that pollinators are essential for açaí fruit production, but that intensive farming practices have eroded the relationship between surrounding forest cover and ecosystem function in floodplains (i.e. conversion of native forest into simplified agroforests) and increased the frequency of antagonistic interactions in uplands (e.g. high ant densities). These findings underline the value of extensive management practices, such as the maintenance of other tree species within farms and adjacent unmanaged forest patches, to ensure the long‐term sustainability of açaí fruit production in the Amazon river delta.

Abstract.  The New World halictid bee genus Augochlorella (Augochlorini) is revised. Sixteen species are recognized, with five described as new: Augochlorella acarinata sp. n., A. una sp. n., A. meridionalis sp. n., A. stenothoracica sp. n. from South America, and A. karankawa sp. n. from U.S.A. The following new synonymies are proposed: Augochlorella michaelis (Vachal) with A. urania (Smith), A. edendata Michener with A. comis (Vachal); A. striata (Provancher) with Augochlorella aurata (Smith) and A. neglectula maritima Ordway with A. neglectula (Cockerell). The female of A. tredecim (Vachal) and the male of A. iopoecila Moure are described for the first time. Keys to the species are provided. Cladistic analysis of adult morphological characters corroborates Engel's hypotheses of monophyly of Augochlorella phylogenetic relationships with related genera as follow: (Augochlorella ((Ceratalictus, Pereirapis) Augochlora)). Vicariant events shown in the cladistic analyses are discussed, and an account of distribution is presented.

Little is known about the composition of the bee community in the Cerrado-Amazon transition area. Herein, we present the results of a bee survey done within the municipality of Conceição do Araguaia, in the state of Pará. Six fragments were sampled twice (once in the dry season and once in the rainy season) using three methods of collecting: arboreal pitfalls with urine, scent traps, and pan traps. We recorded 67 bee species, distributed in 28 genera and eight tribes. Except for Partamona chapadicola, which is endemic to the Cerrado biome, the remaining species we sampled occur in the Amazonian Forest. Of those, 15 species are considered endemic to the Amazonian biome (four Euglossini, eight Meliponini, one Paratetrapedia, one Xylocopa and one Augochlorini), while 27 occur in forest and areas of Cerrado (seven Euglossini, fifteen Meliponini, two Paratetrapedia, one Xylocopa and two Augochlorini). Among 53 species sampled (disregarding the Euglossini species which were sampled almost exclusively with scent), 41 were captured with arboreal pitfall traps. Of those, 20 species were from the Meliponini tribe.

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This work investigated Augochloropsis iris, its annual colony cycle, brood size and survival rate, caste differentiation, and sex ratio, and is the first detailed account of a clearly eusocial species of this genus. The population studied is located in the Campos do Jordão State Park, São Paulo, Brazil. The annual colony cycle extends from August to March and consists of three phases of cell provisioning separated by two phases of inactivity, and followed by an emergence of future queens and males. Provisioning during the first phase is carried primarily out by solitary females. The daughters, after emerging from the cells, remain in the natal nests, carrying out foraging activities, while the mother engages in reproduction. New nests are initiated during each of the provisioning phases by solitary females, principally by females from the second-phase brood which, soon after emerging from the cells, leave their natal nests to found their own nests, which they provision during the third phase. The females resulting from the third-phase brood in general mate and excavate their own nests, in which they diapause, with provisioning delayed until the following August. On average, the queens are significantly larger (5 %) than the workers. In general, the workers do not have developed ovaries, but all are mated. Kin selection can be accepted as the selective force responsible for worker behavior of A. iris in eusocial colonies when the queen has mated once and semisocial colonies if the queen mated only once. The percentage of males produced in the first, second and third broods and in the brood of new nests founded by solitary females active in the second and third phases was: 20.7 %, 22.2 %, 13.3 % and 0.0 % respectively. The resultant sex ratio of the third brood suggests that the third-phase workers of eusocial nests are at least in partial control of their colony's sex ratios, in cases where the queens mated only once.