Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms.

Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.

Stingless Bees as Alternative Pollinators of Canola.

Alternative pollinators can ensure pollination services if the availability of the managed or most common pollinator is compromised. In this study, the behavior and pollination efficiency of Apis mellifera L. and two species of stingless bees, Plebeia emerina Friese and Tetragonisca fiebrigi Schwarz, were evaluated and compared in flowers of Brassica napus L. 'Hyola 61'. A. mellifera was an efficient pollinator when collecting nectar because it effectively touched the reproductive organs of the flower. In contrast, stingless bees were efficient pollinators only when collecting pollen. The number of pollen grains deposited on the stigma after a single visit by worker bees of the three species was greater than the number of grains resulting from pollination without the bee visits. On average, the three species deposited enough pollen grains to fertilize all of the flower ovules. A. mellifera and P. emerina had similar pollination efficiency because no significant differences were observed in the characteristics of the siliques produced. Although T. fiebrigi is also an effective pollinator, the seed mass produced by their pollination was lower. Native bees promoted similar rates of fruit set compared with A. mellifera. Thus, P. emerina has potential to be used for pollination in canola crops.

Bradysia sp. em morangueiro / Bradysia sp. in strawberry

No trabalho, relatam-se os primeiros registros de Bradysia sp. (Insecta: Diptera: Sciaridae) em morangueiro (Fragaria x ananassa Duch.), cultivado no Município de Eldorado do Sul, RS. O cultivo foi realizado em sacolas com três metros de comprimento, preenchidas com substrato composto de casca de arroz e turfa, dispostas horizontalmente sobre bancadas de madeira, em ambiente protegido. A presença de Bradysia sp. foi observada na segunda quinzena de agosto de 2005. Neste trabalho, estão descritos os sintomas apresentados no morangueiro pela praga, prováveis conseqüências sobre o aparecimento de doenças e uma breve descrição morfológica da Bradysia sp., adulto e fase larval.

This paper describes the first record of Bradysia sp. (Insecta; Diptera; Sciaridae) in strawberry (Fragaria x ananassa), cultivated in the city of Eldorado do Sul, RS, Brazil. Strawberry was planted in plastic bags filled with a mixture of burnt rice hulls and peat and cultivated in a greenhouse. The presence of Bradysia sp was noticed in the second fortnight of August, 2005. The symptoms in strawberry and the probable consequences in terms of disease arising were described in the present study, as well as the morphological characterization of Bradysia sp. and its illustrations.

Meliponicultura no Rio Grande do Sul: contribuição sobre a biologia e conservação de Plebeia nigriceps (Friese 1901) (Apidae, Meliponini) / Meliponiculture in Rio Grande do Sul: contribution to the biology and conservation of Plebeia nigriceps (Friese, 1901) (Apidae, Meliponini)

Plebeia nigriceps é um meliponíneo pequeno (3 mm) encontrado em abundância em algumas regiões do Rio Grande do Sul, que juntamente com Plebeia wittmanni e Plebeia julianii constituem-se em espécies próximas. Revimos alguns tópicos da bibliografia sobre estas espécies e mostramos um exemplo de meliponicultor que conserva Plebeia nigriceps, tendo adquirido conhecimentos empíricos de sua biologia e habilidades no uso de ninhos-armadilha para seus enxames.

Plebeia nigriceps is a small Meliponini bee that occurs in large quantities in some areas of Rio Grande do Sul. Plebeia wittmanni, Plebeia juliani and Plebeia nigriceps are considered close related. We reviewed what is in literature about these species and show an example of stingless bee beekeeper that conserves Plebeia nigriceps and learned about its behavior and reproduction, using trap nests for attracting their swarms.