Jean-Marie,
 
The best reference I know of relating to your query is a publication
issued by the USDA in 1976 entitled "Insect Pollination of Cultivated
Plants" by S.E. McGregor.
 
Agriculture Handbook No. 496
 
For sale by the Superintendent of Documents, U.S. Government Printing
Office  Washington, D.C. 20402
 
Stock No. 001-000-03549-5
 
Hope this is of some help.
 
 
mac