Acknowledgements
We wish to thank Renato Ripa (Instituto de Investigaciones Agropecuarias, Chile), Ariel Camousseight (National History Museum of Science from Santiago, Chile), James Austin (BASF, Research Triangle Park, NC, USA), Uwe Noldt (Germany) and Guillaume Baudouin (Paris City Hall, France) for giving us samples. This work was supported by USDA-NRICGP grants to ELV (00-35302-9377 and 2002-35352-12490), the Urban Entomology Endowment at Texas A&M University and CNRS grants and contracts to AGB.