Aplicação de inseticida e seus impactos sobre a visitação de abelhas (Apis mellifera L.) no girassol (Helianthus annuus L.).

O objetivo deste estudo foi verificar a ação do uso do inseticida Imidacloprido + beta-ciflutrina em relação ao número de visitas de abelhas Apis mellifera nas inflorescências do girassol. O trabalho foi conduzido no mês dezembro de 2008 na Estação Experimental da Copagril, no município de Marechal Cândido Rondon, PR. Antes do período de florescimento foram marcadas cinco plantas dos híbridos de girassol M734, Charrua, Aguará e Helio 250, com quatro repetições cada. Dois observadores permaneceram dois minutos em cada inflorescência, contando o número de abelhas visitantes em dois intervalos de tempo (8h30min às 10h e 15h30min às 17h). A contagem ocorreu antes da aplicação do inseticida e 12 horas após a utilização do produto. Verificou-se que houve efeito significativo de inseticida sobre a visitação de abelhas nos híbridos M734, Aguará e considerando todos os genótipos de girassol. Não houve efeito do inseticida sobre a visitação nos híbridos Charrua e Helio 250

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

PRODUÇÃO DE GENÓTIPOS DE GIRASSOL PELA AÇÃO DE INSETOS POLINIZADORES

O objetivo do trabalho foi verificar a polinização realizada por insetos sobre características produtivas em genótipos de girassol. O delineamento experimental empregado foi o de blocos casualizados completos, em esquema de parcelas subdivididas, com 16 tratamentos, e quatro repetições. Os tratamentos foram constituídos pela combinação de oito híbridos de girassol (Multissol, M734, Catissol 01, Charrua, MG2, Aguará, Helio 360 e Embrapa 122), casualizados nas parcelas, e dois tipos de polinização, uma sem proteção e outra com proteção dos capítulos com sacos de filó, que foram alocados nas subparcelas. Os capítulos sem proteção apresentaram maior (p<0,05) diâmetro, massa de capítulo e massa de aquênios por inflorescência, nos híbridos Multissol, M734, Catissol 01, Aguará e Embrapa 122, em relação aos capítulos isolados da polinização com filó. Não houve diferença significativa entre inflorescências desprotegidas e protegidas com filó no diâmetro de capítulo, dos híbridos Helio 360 e MG2, na massa de capítulo, para os híbridos Helio 360 e Charrua, e na massa de aquênios por inflorescência para os híbridos Helio 360, MG2 e Charrua. A visitação de abelhas gera benefícios na produtividade do girassol

Characterization of Lavandula spp. Honey Using Multivariate Techniques

Traditionally, melissopalynological and physicochemical analyses have been the most used to determine the botanical origin of honey. However, when performed individually, these analyses may provide less unambiguous results, making it difficult to discriminate between mono and multifloral honeys. In this context, with the aim of better characterizing this beehive product, a selection of 112 Lavandula spp. monofloral honey samples from several regions were evaluated by association of multivariate statistical techniques with physicochemical, melissopalynological and phenolic compounds analysis. All honey samples fulfilled the quality standards recommended by international legislation, except regarding sucrose content and diastase activity. The content of sucrose and the percentage of Lavandula spp. pollen have a strong positive association. In fact, it was found that higher amounts of sucrose in honey are related with highest percentage of pollen of Lavandula spp.. The samples were very similar for most of the physicochemical parameters, except for proline, flavonoids and phenols (bioactive factors). Concerning the pollen spectrum, the variation of Lavandula spp. pollen percentage in honey had little contribution to the formation of samples groups. The formation of two groups regarding the physicochemical parameters suggests that the presence of other pollen types in small percentages influences the factor termed as "bioactive", which has been linked to diverse beneficial health effects.info:eu-repo/semantics/publishedVersio

Honey from Stingless Bee as Indicator of Contamination with Metals

Melipona scutellaris (Apidae, Meliponini) is one of the main species of stingless bees used in beekeeping in the Northeast of Brazil. We examined the honey from M. scutellaris as an indicator to evaluate the levels of metals at sampling sites subject to a broad spectrum of environmental pollutants. The collections were carried out in the urban-industrial area of Salvador, Bahia and the metropolitan region. Samples (n= 58) were submitted to the nitroperchloric digestion procedure. We used the inductively coupled plasma optical emission spectrometry technique (ICP OES) to determine the concentration of metals (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) in the samples. The studied metals were detected among the samples, which presented tolerable levels according to current Brazilian legislation and recommendations from the World Health Organization (WHO), except for Cr, which presented mean values higher than the threshold for all sampling sites. The detection of the analyzed metals indicates that the honey of M. scutellaris is a useful tool to evaluate the presence of environmental contaminants; therefore, it can be considered a good indicator of environmental contamination for monitoring a particular region and preventing issues due to the release of metals into the environment

Chemical composition and biological activities of mono- and heterofloral bee pollen of different geographical origins

Recent research shows variations in pollen chemical constituents and, consequently, in their therapeutic properties. Mono and multifloral bee pollen extracts were investigated for antioxidant and enzyme inhibitory activity properties, phenolic compounds and fatty acid composition. Generally, Eucalyptus spp. and multifloral extracts exhibited potent inhibitory activity against -amylase, acetylcholinesterase, tyrosinase, lipoxygenase, lipase and hyaluronidase. On the other hand, Miconia spp. demonstrated higher antihemolytic activity. Cocos nucifera and Miconia spp. extracts exhibited important antioxidant properties in the different assays (ABTS, DPPH, -carotene/linoleic acid and reducing power). Moreover, these extracts had greater amounts of total phenols and flavonoids in comparison to others. The increase in antioxidant activity (decrease in EC50 values) was accompanied by an increase in the amount of total phenols in the extracts. The pollen extracts contained linoleic acid and -linolenic acid as major fatty acids, followed by palmitic acid, and oleic acid. In this study, differences were observed in both chemical constituents and biological activities of the samples related to the geographical and botanical origin of bee pollen.We thank the Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES) and National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq) for a scholarship granted to Jucilene Silva Araújo (CAPES), for a research scholarship granted to Carlos Alfredo Lopes de Carvalho (CNPq), financial support for the project and scholarship (CAPES) granted to Emerson Dechechi Chambó, Leticia M. Estevinho and Samira Maria Peixoto Cavalcante da Silva. We thank beekeeper Márcio Brazil for the pollen samples. This work was supported by the strategic programmer UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the Fundação para a Ciência e a Tecnologia (FCT), Portugal and by the European Regional Development Fund (ERDF) through the COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI).info:eu-repo/semantics/publishedVersio

Toxicity of Fenpyroximate, Difenoconazole and Mineral Oil on Apis mellifera L. Introduction

Bees of genus Apis are the main crop pollinators; however, the use of pesticides in agriculture may intoxicate them during foraging. In this study, we evaluated the toxic eff ects caused by difenoconazole (fungicide), fenpyroximate (acaricide) and mineral oil (adjuvant) used alone and associated (pesticide + adjuvant) on workers of Apis mellifera L. Bees were exposed to product doses recommended by manufacturers, orally and in contact on a contaminated surface in a controlled environment. All products presented low lethality, both in isolation and combination (except for difenoconazole via contact), however, they all showed toxic effects. The results showed that combination of pesticides with adjuvant augmented toxic eff ects