Honey bee visitation to sunflower: effects on pollination and plant genotype

Sunflower (Helianthus annuus L.) is an allogamic plant, which needs insects on flowering, especially the honeybees for seed production. Collecting nectar and pollen by honeybees in agricultural crops is essential to apiculture, as well as a better understanding of plant biology. The foraging behavior of Africanized Apis mellifera L. (Hymenoptera, Apidae) and its efficiency of pollination on seed yield of sunflower genotypes (open pollination and restricted pollination) were evaluated. There were peaks of visits by A. mellifera for nectar collection on the 2nd and 3rd flowering days between 7h00 and 8h30. The average density of A. mellifera during increased visitation ranged from 2.27 to 2.94 bees per capitulum. Nectar collecting bees were more frequent (2.28 bees per capitulum) than pollen collecting (0.40 bees per capitulum). On the 3rd flowering day, Helio 360 and Aguará hybrids had higher (p ≤ 0.05) number of bee visits per flower head than the other genotypes. Seed yield was 43 % higher (p ≤ 0.05) from sunflower plants that were visited by pollinator-insects compared with plants restricted to pollinators

Botanical profile of bee pollen from the southern coastal region of Bahia, Brazil

This paper aims to identify the botanical origin of pollen loads collected by Apis mellifera L. in Canavieiras municipality, Bahia state. It provides a list of polliniferous plant species from the Atlantic Forest biome that are important for the development of regional apiculture. Using the acetolysis method, 35 bee-pollen samples were analyzed qualitatively and quantitatively. Results showed that pollen types Elaeis (23.99%), Mimosa pudica (22.78%) and Cecropia (13.68%) were the most abundant among the samples. These also showed the highest relative frequencies of the material studied and were important pollen sources for bees in the study area

Levantamento da flora apícola em Santa Luzia do Paruá, Sudoeste da Amazônia, Maranhão Survey of bee flora in Santa Luzia do Paruá, Southwest Amazonia, Maranhão

Foi realizado o levantamento das plantas visitadas por Apis mellifera L. através de análise polínica no município de Santa Luzia do Paruá, Maranhão, localizado a noroeste do Estado, em região amazônica. A temperatura média anual varia entre 26 °C e 27 °C, com umidade relativa do ar anual entre 79 a 82% e precipitação pluviométrica entre 2000 a 2400 mm anuais. O estudo foi conduzido entre agosto de 2005 e julho de 2006 em três apiários da região, com coletas mensais de mel, pólen e plantas, que foram submetidas ao método de acetólise. Os tipos polínicos das amostras de mel foram identificados e contados para a determinação da freqüência relativa média. Nas amostras de pólen foi realizada apenas a identificação dos tipos polínicos por meio da comparação com os polens das plantas (botões florais) depositados em coleção de referência. As principais famílias utilizadas por A. mellifera foram Amaranthaceae, Arecaceae, Asteraceae, Urticaceae, Euphorbiaceae, Lamiaceae, Fabaceae-Mimosoideae, Flacourtiaceae, Myrtaceae, Poaceae e Rubiaceae. Em amostras de mel, no período chuvoso destacaram-se os tipos polínicos de Mimosa pudica, Borreria e um tipo indeterminado da família Arecaceae. No período de safra foram representativos Hyptis e um tipo indeterminado de Asteraceae. Os tipos polínicos mais constantes nas amostras de pólen foram Euterpe oleracea, Asteraceae tipo 1, Mimosa pudica e Borreria.<br>The plant species visited by Apis mellifera L. were surveyed by pollen analysis in Santa Luzia do Paruá municipality, located in northwestern Maranhão state. Natural vegetation is Amazon rainforest, mean annual temperature varies between 26°C and 27°C, relative air humidity between 79 and 82%, and total rainfall between 2000 and 2400 mm. This study was conducted from August 2005 to July 2006 in three apiaries of the region, with monthly sampling of honey, pollen and plants. The samples were analyzed by the acetolysis method. The pollen types were identified and counted in honey samples to determine mean frequency of the three apiaries. In the pollen samples, pollen types were identified by comparison with the pollen of plants (flower buds) deposited in the reference collection. The main plant families used as floral resource by A. mellifera are Amaranthaceae, Arecaceae, Asteraceae, Urticaceae, Euphorbiaceae, Lamiaceae, Fabaceae-Mimosoideae, Flacourtiaceae, Myrtaceae, Poaceae and Rubiaceae. In the honey samples, the pollen types of Mimosa pudica, Borreria and members of the Arecaceae family were most important during the rainy season. At harvest time (transition between rainy and dry season), Hyptis, Borreria, and an undetermined pollen type of the Asteraceae family were most important. The pollen types that show major constancy in the sample pollen were Euterpe oleracea, Asteraceae type 1, Mimosa pudica and Borreria