Mud-Ball construction by sceliphron Mud-Dauber wasps (Hymenoptera: Sphecidae): A comparative ethological study

Thanks are extended to the farmers which kindly permitted us to carry out the study on their proprieties. F. Rigato kindly helped determine the species of wasps observed in the study. The present work was supported by a 3-yr Fondo per gli Investimenti della Ricerca di Base grant, RBAU019H94-001 (2001), and by a postdoctoral contract to CP (Program JAE-Doc “Junta para la Ampliacion de Estudios” funded by the Spanish Research Council (CSIC) and the FSE).