0187-5779 0187-5779 S0187-57792011000300267 Mexico Mexico Mexico 00 09 2011 00 09 2011 29 3 267 276

2004 50 965-71 1989 12 827-38 2001 24 147-58 2007 85-101 2005 28 737-49 1965 595-622 2000 23 741-57 2003 26 257-68 2008 311 161-72 1995 93 750-6 1991 14 257-65 2004 50 973-81 2003 119 400-8 2006 89 113-26 1991 274 601-6 1986 9 195-214 2006 29 615-28 1986 9 695-713 1990 94 607-13 1998 21 815-25 1983 114 85-92 1998 99 127-36 2007 61-83 1992 15 1519-30 1991 297-328 2003 26 2211-30 1992 140 527-30 1984 Wageningen, The Netherlands 633-50 2001 15 71-92 1986 9 609-46 1994 34 715-21