Flower-visiting guild associated with the Caatinga flora: trophic interaction networks formed by social bees and social wasps with plantsGilberto M. de Mendonça Santos, Cândida M. Lima Aguiar and Marco A.R. MelloApidologie, 41 4 (2010) 466-475DOI: https://doi.org/10.1051/apido/2009081