Pompiloidea by Karl V. Krombein 1523 



Pompilidae 1523 



Rhopalosomatidae 1570 



Sphecoidea by Karl V. Krombein 1573 



Ampulicidae 1574 



Sphecidae 1575 



Pemphredonidae 1595 



Larridae 1617 



Crabronidae 1650 



Mellinidae 1683 



Nyssonidae 1684 



Philanthidae 1720 



Apoidea by Paul D. Hurd, Jr 1741 



Colletidae 1748 



Oxaeidae 1770 



Andrenidae 1772 



Halicitidae 1932 



Melittidae 1978 



Megachilidae 1981 



Anthophoridae 2081 



Apidae 2188 



Institutional Affiliation of Contributing Authors 



Smithsonian Institution: Paul D. Hurd, Jr., Karl V. Krombein, Carl F. Muesebeck 

 U.S. Department of Agriculture: B. D. Burks, Robert W. Carlson, E. E. Grissell,' 



Paul M. Marsh, David R. Smith 

 University of California, Riverside : Gordon Goi-dh 



Vll 



