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ABSTRACT-Aspects related to the floral biology of Citrus sinensis 'Pera Rio' variety were studied in the present work aiming to obtain information about the pollination ecology in the local agriculture. Studies of flowering, anthesis, pollen / ovule ratio, stigmatic receptivity, pollen viability, nectar characterization and floral visitors were carried out. From the data studied, the following information was obtained: C. sinensis variety 'Pera Rio' flourishes in two annual periods (dry and rainy), the anthesis occurs from 9:00 AM with duration of 24 hours, during which period stigma receptivity, pollen viability and nectar secretion are highly significant, demonstrating that the species also possesses characteristics of allogenic plants. Apis mellifera was a floral visitor, with a greater number of individuals with a Relative Frequency (RF) of 51.1%. Melipona scutellaris obtained second place in visits with RR = 23.6%; Followed by Trigona spinipes with FR = 17.7%. The two seasons (dry and rainy) presented high similarity (Morisita index = 0.64). C. sinensis has floral biology favorable to cross pollination and bees A. mellifera and M. scutellaris are potential pollinators of this fruit in the conditions in the region of the Recôncavo Baiano. The reproductive system of C. sinensis is mixed, being favorable to entomophilic pollination. Index terms: Apoidea, citricultura; pollination; bee population, orange. BIOLOGIA DA POLINIZAÇÃO DE Citrus sinensis VARIEDADE 'PERA RIO'RESUMO-Aspectos relacionados à biologia floral de Citrus sinensis var Pera Rio foram estudados no presente trabalho, com o objetivo de obter informações da ecologia da polinização na agricultura local. Foram realizados estudos da floração, antese, razão pólen/óvulo, receptividade estigmática, viabilidade polínica, caracterização do néctar e visitantes florais. A partir dos dados estudados, foram obtidas as seguintes informações: C. sinensis var Pera Rio floresce em dois períodos anuais (seco e chuvoso), a antese ocorre a partir das 9:00 da manhã com duração de 24 horas, período pelo qual a receptividade do estigma, viabilidade polínica e a secreção de néctar são altamente significativos demonstrando que a espécie também possui características de plantas alogâmicas. Apis mellifera se destacou como visitante floral, com um maior número de indivíduos com Frequência Relativa (FR) de 51,1%. Melipona scutellaris obteve segundo lugar nas visitas com FR = 23,6%; seguida por Trigona spinipes com FR = 17,7%. As duas estações (seca e chuvosa) apresentaram similaridade alta (índice de Morisita = 0,64). C. sinensis possui biologia floral favorável à polinização cruzada e as abelhas A. mellifera e M. scutellaris são potenciais polinizadores dessa fruteira nas condições do Recôncavo Baiano. O sistema reprodutivo de C. sinensis é misto, sendo favorável à polinização entomófila. Termos para indexação: Apoidea, citricultura; polinização; população de abelhas, laranja.

Entomopathogenic fungi are frequently used as an alternative method for insect pest control. However, only a few studies have focused on the effect of these fungi on bees and on the selectivity of fungi to beneficial organisms in agroecosystems. The objective of the present study was to assess the susceptibility of worker bees of the species Melipona scutellaris (locally known as "uruçu") to the isolate (Biofungi 1) of the entomopathogenic fungus Beauveria bassiana. The experiment was carried through indirect contact between the fungal suspension and newlyemerged bees and topical application of the fungal suspension on the back of newly-emerged bees. The sampling design was completely randomized and comprised five treatments, which included four different concentrations of the fungus: 1 x 10 5 , 1 x 10 6 , 1 x 10 7 , 1 x 10 8 conidia/ml, and a control composed of distilled water. Each treatment had five replicates. The mortality data were subjected to an analysis of variance and a probit regression analysis, which provided an estimate of the lethal dose to 50% of the population (LD 50). The adjustment of the curves to the model was tested with a chi-squared test and differences between curves were tested with a test for parallelism. Beauveria bassiana was virulent to uruçu bees, killing the bees at the lowest dose used. These findings may help minimize the impact of this entomopathogen and, therefore, contribute to the maintenance of natural populations of these insects.

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