Cienc. anim. bras., Goiânia, v.16, n.

ABSTRACT.Regional-level studies of floral resources used by social bees for honey production can contribute to the improvement of management strategies for bee pastures and colonies, by identifying the most visited flowers and thus characterizing the various geographical origins of honey. The objective of this study was to investigate, through pollen analysis, the types of pollen and nectar sources used by the uruçu bee (Melipona scutellaris L.) in the North Coast of Bahia. Honey samples were taken monthly from five colonies in an apiary from August 2010 to July 2011. Pollen analysis of honey was performed by using the acetolysis method, followed by qualitative and quantitative analysis of pollen grains. Fifty pollen types belonging to 40 genera and 17 families were identified. The results indicate predominance of pollen types belonging to the families Fabaceae and Myrtaceae, which suggests that the bees preferred foraging from trees and shrubs. These plants should be included in regional reforestation projects in order to improve management of this bee species and honey production.Keywords: stingless bees, Meliponinae, pollen collection, Atlantic Forest, trophic niche.Espectro polínico do mel da abelha de uruçu (Melipona scutellaris Latreille, 1811) (Hymenoptera: Apidae) do Litoral Norte do estado da Bahia RESUMO: Estudos em nível regional dos recursos florísticos utilizados por abelhas sociais para a produção de mel podem contribuir para a melhoria das estratégias de manejo do pasto meliponícola e das colônias, através da identificação das flores mais visitadas, e dessa forma caracterizar a origem geográfica do mel. O objetivo desta pesquisa foi investigar, por meio da análise polínica, os tipos de vegetação fornecedora de néctar e pólen para a abelha uruçu (Melipona scutellaris L.) no Litoral Norte da Bahia. Foram realizadas coletas quinzenais em 5 colônias de meliponário, de agosto de 2010 a julho de 2011. A análise polínica do mel foi conduzida através do método da acetólise, seguida por análise quali-quantitativa dos grãos de pólen. Foram identificados 50 tipos polínicos pertencentes a 40 gêneros e 17 famílias. Os resultados apontam para a dominância dos tipos polínicos pertencentes às famílias Fabaceae e Myrtaceae, sugerindo que essas abelhas preferem forragear em árvores e arbustos. Esses tipos vegetais predominantes devem ser incluídos nos projetos regionais de reflorestamento, visando favorecer o manejo dessa espécie de abelha e melhorar a produção de mel.Palavras-chave: abelhas sem ferrão, Meliponinae, coleta de pólen, Mata Atlântica, nicho trófico.

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.

Outbreaks of three orthopteran species—Tropidacris collaris (Stoll), Cornops frenatum frenatum (Marschall) and Parascopas obesus (Giglio-Tos)—occurred in three different regions of Brazil during the summers of 2012 and 2013. Insects were observed causing severe damage in commercial crops and subsistence farming areas. In this study, the three species were shown to be susceptible to infection with an oil-based formulation of the fungus Metarhizium acridum under laboratory conditions. In this article, we briefly discuss insect mortality levels for each species and behavioural response to infection. This is the first report of the pathogenicity of the entomopathogenic fungus M. acridum to P. obesus, C. f. frenatum and T. collaris.