Annual survival rate of tropical stingless bee colonies (Meliponini): variation among habitats at the landscape scale in the Brazilian Atlantic Forest

Stingless social bees live in perennial colonies whose longevity is influenced by various ecological factors. This study analyzed the influence of habitat anthropization and native forest regeneration stage on the longevity of natural colonies at the landscape scale. Random sampling of 25x25m plots, totaling 30ha per habitat type, located and monitored 118 nests of 14 species in the forest and 105 nests of six species in the anthropic habitat. Significant differences in colony longevity were observed between young and long-lived forests  and between long-lived forests and anthropized habitat. Shorter longevities have generally been associated with a set of smaller-bodied species residing in anthropized habitats. The greatest longevities were associated with the three abundant and exclusive forest species, and was similar in the two forest regeneration stages: Melipona scutellaris, Scaptotrigona xanthotricha and Scaptotrigona bipunctata had high annual survival rates ranging from 87% to 93%. Another abundant species in the landscape was Tetragonisca angustula, a small habitat-generalist with short longevity (63%) that varied among habitats. Euclidean distance analysis based on this generalist placed young forest closest to anthropic habitat, and grouped the replicates of long-lived forest. Considering spatial variation in the life history traits, we infer that, among prospective landscape habitats, the Atlantic Forest favors stingless bees with high colonial longevity. On the other hand, generalists, such as T. angustula, with shorter colonial longevity and high reproduction rates are being favored by the expansion of anthropized habitats in place of deforested areas

Permeability of matrices of agricultural crops to Euglossina bees (Hymenoptera, Apidae) in the Atlantic Rain Forest

International audienceAbstractWe evaluate the permeability of three matrices of arboreal crops for the Euglossina bees that inhabit the Brazilian Atlantic rainforest hotspot. The comparisons of occurrences and abundances within three mosaics of forest and extensive arboreal crops (piassava palm, oil palm, and rubber tree) showed that all the matrices were permeable to most orchid bees. The piassava palm was the most permeable, where the spatial distribution of all species of Euglossina did not differ between forest fragments and matrix. The oil palm has shown some loss of permeability to Eulaema atleticana, while the rubber tree crop was not so permeable to El. atleticana and Euglossa imperialis. Euglossa iopoecila was sampled only in the forest fragments. At the present scale of forest cover in the three studied mosaics (10 to 40 %), the arboreal matrices are contributing towards the functional connectivity in the Atlantic Rain Forest at both scales: the landscape mosaic and the Brazilian Atlantic Forest corridor

Estratificação da atividade de coleta de essência por abelhas Euglossina em um remanescente de Mata Atlântica na Reserva da Michelin, Bahia, Brasil

The microclimate of the tropical forests presents a great vertical variation. Particularly, the difference between the canopy and the understory constitutes micro-habitats that demand particular adaptations of the animals and can create the stratification of the same ones. The objective of this study was to verify if there is a difference in the collection essence activity by Euglossina bees between canopy and understory of Atlantic forest. The sampling was collected in 16 drafted points throughout a track of 4.370m, in a forest remnant, the north of the Central Corridor of Atlantic Forest. The total of 566 species were sampled distributed in species: Euglossa (5), Eulaema (3) and Exaerete (1).  The canopy (8-12 m) and the understory (1,5-2,0 m) did not present significant differences in the composition of species of Euglossina (p=0.6827). The three more abundant species also showed similar frequencies in the canopy and the understory. This study suggests that there isn’t stratification of the collecting essence activity by Euglossina bees, in contrast with previous studies.O microclima nas florestas tropicais apresenta grande variação vertical. Em particular, a diferença entre dossel e estrato inferior do sub-bosque constitui micro-hábitats que exigem adaptações particulares dos animais e podem propiciar a estratificação dos mesmos. O objetivo deste estudo foi verificar se existe diferença na atividade de coleta de essência por abelhas Euglossina, entre dossel e sub-bosque da Mata Atlântica. As coletas foram feitas em 16 pontos sorteados ao longo de uma trilha de 4.370m, em um remanescente florestado, no norte do Corredor Central da Mata Atlântica. Foram amostrados 566 espécimes assim distribuídos em espécies: Euglossa (5), Eulaema (3) e Exaerete (1). O dossel (8-12 m) e o sub-bosque (1,5-2,0 m) não apresentaram diferenças significativas na composição de espécies de Euglossina (p=0.6827). As três espécies mais abundantes também apresentaram freqüências similares no dossel e no sub-bosque. Este estudo sugere que não há estratificação da atividade de coleta de essência por abelhas Euglossina, contrastando com estudos prévios