Pollen storages in nests of bees of the genera Partamona, Scaura and Trigona (Hymenoptera, Apidae)

Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon

Análise do pólen encontrado em amostras de mel de Apis mellifera L. (Hymenoptera, Apidae) em uma área de savana de Roraima, Brasil

Foram analisadas amostras de mel de um apiário localizado na Aldeia do Contão, Roraima, Brasil. As amostras foram obtidas das colheitas nos meses de outubro e dezembro de 1996 e janeiro, fevereiro e março de 1997. Foram identificados um total de 20 tipos polínicos distribuídos em 18 gêneros e 13 famílias. As famílias: Mimosaceae (4 espécies), Anacardiaceae (3 espécies), Sterculiaceae (2 espécies), Caesalpiniaceae (2 espécies) e Amaranthaceae (2 espécies) foram as mais representadas, as demais por uma única espécie. Os tipos polínicos mais frequentes foram: Mimosa polydactyla H.B.K (outubro e dezembro de 1996), Curatella americana L. (janeiro, fevereiro e março de 1997). Encontrou-se três correlações significativas entre as frequências dos tipos polínicos de: Curatella americana L. X Mimosa polydactyla H.B.K (r = -0,99), Curatella americana L. X Astronium sp (r = 0,95) e Mimosa polydactyla H.B.K e Astronium sp (r = -0,91

Pollen harvest features of the Central Amazonian bee Scaptotrigona fulvicutis Moure 1964 (Apidae: Meliponinae), in Brazil

Over a twelve-month period, pollen loads transported by Scaptotrigona fulvicutis Moure 1964 were collected from the workers corbiculae right after the hive entrance closure in an area of old secondary forest mixed with some exotic fruit trees and ornamentals. Once the pollen grains were identified, their monthly frequency in the samples and grouping by botanical family established that Mimosaceae, Myrtaceae and Sapindaceae were the most frequently visited. The workers harvested the pollen from 97 plant species distributed in 73 genera and 36 families, mostly: Stryphnodendron guianense (Aubl.) Benth. in April (57,37%) and Schefflera morototoni (Aubl.) Frodin in May (54,73%). The harvested pollen types abundance matrix showed that there was little species dissimilarity between the months, which resulted in the formation of two large groups

Reproductive biology of Davilla kunthii A. St-Hil. (Dilleniaceae) in Central Amazonia

This survey aimed at describing the interactions of floral visitors and Davilla kunthii A. St.-Hil. as well as characteristics of its reproductive biology in Itacoatiara, state of Amazonas, Brazil. Tests of the breeding system were performed. The guild of visitors was described according to richness, abundance, relative frequency and constancy. The breeding system tests indicated that D. kunthii is self-compatible. The pollination system was characterized as generalist, with 39 visitor species, from three different orders. Bees were the main group of pollinators, thus some behavioural aspects were described. Th e period of highest foraging activity was between 7 and 10 am. Some species presented agonistic and monopolistic behaviour. Given the behaviour and destructive potential, the Curculionidae seem to have a greater impact as seed predators than pollinators

Late Quaternary vegetation dynamics from central parts of the Madeira River in Brazil

The present study reconstructs the paleovegetation of a varzea (seasonally flooded) forest in the central parts of the Madeira River floodplain in Brazil using palynological data. Forty-nine cut-bank sediment samples from the Madeira River were processed in the study; from these, ten samples contained pollen: two contained pollen from the Middle Pleniglacial age, one contained pollen from the Tardiglacial age, six contained pollen from the Holocene, and one contained more recently deposited pollen. The Middle Pleniglacial pollen belonged to a primary succession varzea forest, while the Tardiglacial pollen represented a late succession varzea forest. On the other hand, the three Holocene samples showed the characteristic composition of chavascal (water-logged forest) or lacustrine varzea forest, and three samples belonged to a late succession varzea forest. The most recent pollen deposit represented a secondary succession varzea forest. This paleovegetation showed a typical mosaic distribution, which may be explained by the fluvial dynamics, high species richness and diversity in the varzea forest, and the presence of dominant species