Avaliação bioquímica do extrato etanólico de própolis em ratos

Propolis is a natural product collected by honey bees containing, among other biochemical constituents, a variety of flavonoids. Propolis is a folk medicinal employed for treating various diseases. It is alleged to exhibit a broad spectrum of bioactivities. The aim of this study was to evaluate the effect of ethanolic extract of propolis (EEP) of species Plebeia droryana and Scaptotrigonea bipunctata through biochemical parameters. Rats were divided into 4 groups: (G1) untreated; (G2) ethanol treated; (G3) treated EEP of Plebeia droryana; (G4) treated of Scaptotrigonea bipunctata. The EEP (100 mg/kg b. w., daily) was administered orally to the animals, for 30 days. Treatment with EEP for two species showed reduction (p<0,05) in serum alanine aminotransferase, aspartato aminotransferase and alkaline phosphatase activity, compared to control ethanol values. The administration of EEP lowered significantly the serum levels of cholesterol (G3= 48,83±5,7 mg/dL; G4=56,91±6,5 mg/dL) and triacylglycerol (G3=45,17±4,16 mg/dL; G4=46,74± 3,90 mg/dL). The serum concentration of albumin (G3=4,16±0,6 g/dL; G4= 3,61±0,36 g/dL) increased (p<0,05) after the administration of EEP, however, it did not affect total protein and glucose concentration. The data suggest that EEP of two species caused alterations of the biochemical parameters.

Isolation and characterization of 15 microsatellite loci in the stingless bee Plebeia remota (Apidae: Meliponini)

The destruction of Brazilian natural habitats has reduced bee populations and negative impacts of native flora pollination have been noticed. This work describes the isolation and characterization of microsatellite loci and evaluates them as molecular markers to study genetic variability of the stingless bee Plebeia remota. A microsatellite enriched genomic library was constructed and 15 primer pairs were designed for this species. The survey was conducted by analyzing 21 unrelated individuals. Genetic diversity indexes were calculated. The mean allelic richness was 6.3, the observed heterozygosity was 0.568, and the percentage of polymorphic loci was 93.33%. Also the primers were tested in cross-species amplification and showed promising results for P. droryana, P. emerina, P. lucii, P. meridionalis, P. pugnax, and P. saiqui. The microsatellite loci described here will be useful to evaluate genetic variability of stingless bees, and certainly will improve our knowledge about population dynamics especially in threatened environments.

Visitantes florais de Lagerstroemia speciosa Pers: (Lythraceae)

Studies were carried out with Lagerstroemia speciosa Pers. on floral reproductive systems, diversity and constancy of visiting insects at different hours of day, the behaviour of these insects at the flowers and the influence of these environmental factors in relation to their visits. The fenology, anthesis and others particularity of this vegetal species was studied. A great diversity of insects was verified visiting the flowers with the predominance of bees. The most frequent and constant species encountered were: Nannotrigona testaceicornis (Lepeletier, 1836) (40,2%), Tetragonisca angustula (Latreille, 1811) (16,9%), Apis mellifera Linnaeus, 1758 (11,8%), Plebeia droryana (Friese, 1900) (9,1 %) e Exomalopsis fulvofasciata (Smith, 1879) (8,5%). The blossoms possessis features of melittophily syndrome and diurnal anthesis. The environmental factors influence the insects foraging activity, mainly temperature, light, time of day, humidity and wind speed. The effective pollinators were the large insects like Bombus morio (Swederus, 1787), Bombus atratus (Franklin, 1913), Centris tarsata (Smith, 1874), Centris flavifrons Fabricius, 1775, Xylocopa suspecta Camargo & Moure, 1988, Xylocopa frontalis (Olivier, 1789) and Eulaema nigrita Lepeletier, 1841.

Visitantes florais de Erythrina speciosa Andr. (Leguminosae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Entomofauna visitante de Belamcanda chinensis (L.) DC (Iridaceae) durante o período de floração

A study of the reproductive biology of B. chinensis (L.) DC. (Iridaceae) was realized comprising floral biology and breeding systems. The floral biology studies included analyses of nectar production, occurence of osmophores, corolla pigments, ultraviolet reflexion and absortion patterns, viability of pollen, pollinators and flower visitors. The breeding systems were studied taking into account the results of manual pollinators tests. B. chinensis is self-compatible bul cross-pollination is more frequent. The effective pollinators are Plebeia droryana (Friese, 1906) (45,7%), Trigona spinipes (Fabricius, 1793) (27,3%), Tetragonisca angustula (Latreille, 1811) (9,3%). Others insects visitors are considered nectar and pollen thieves. The flowering begins generally in January and February. The complete reproductive cicle, as here considered, begining with floral bud production ending with development of mature fruits, lasts January to June. Seed dispersion is ornitocoric.

Mixed colonies of two species of congeneric stingless bees (Hymenoptera: Apinae, Meliponini) display environmentally-acquired and endogenously-produced recognition signals

Nestmate recognition is fundamental for the maintenance of social organization in insect nests. It is becoming well recognized that cuticle hydrocarbons mediate the recognition process, although the origin of recognition cues in stingless bees remains poorly explored. The present study investigates the effects of endogenously-produced and environmentally-acquired components in cuticular hydrocarbons in stingless bees. The tests are conducted using colonies of Plebeia droryana Friese and Plebeia remota Holmberg. Recognition tests are performed with four different groups: conspecific nestmates, conspecific non-nestmates, heterospecifics and conspecific, genetically-related individuals that emerge in a heterospecific nest. This last group is produced by introducing brood cells of P. droryana into a P. remota colony, and the resulting adult bees are tested for acceptance 10 days after emergence. For all groups, 15 individuals are sampled for chemical analysis. The results show the acceptance of all conspecific nestmates, and the rejection of almost every conspecific non-nestmate and every heterospecific bee. Genetically-related individuals emerging from heterospecific nests present intermediate rejection (66.7% rejection). Chemical analysis shows that P. droryana individuals emerging in a P. remota nest have small amounts of alkene and diene isomers found in P. remota cuticle that are not found in workers from the natal nest. The data clearly show that the majority of the compounds present in P. droryana cuticle are endogenously produced, although a few unsaturated compounds are acquired from the environment, increasing the chemical differences and, consequently, the rejection percentages.