AMERICAN WASPS OF THE GENUS SCELIPHRON KLUG 



By Bennet a. Porter 



Of the Bureau of Entomology, United, States Department of Agriculture 



INTRODUCTION 



The conspicuous black-and-yellow thread-waisted wasps of the 

 genus Sceliphron are familiar to all who have taken the least notice 

 of insect life. Equally familiar are the mud nests which these wasps 

 construct on the timbers of buildings and elsewhere, inclosing within 

 them spiders for the sustenance of their progeny. 



The paper here presented, dealing with the genus Scelifhrmi, is 

 a portion of a study made by the writer in 1916 while a graduate 

 student at the Massachusetts Agricultural College, in partial fiulfill- 

 ment of thesis requirements for the degree of doctor of philosophy. 

 Since entering the service of the Bureau of Entomology the writer 

 has had opportunity to study all of the material of this genus in 

 the collection of the United States National Museum, which has 

 aided in clarifying certain points which were in doubt. 



In 1918 Kohl ^ published a revision of the wasps of the subfamily 

 Sceliphroninae of the world. In this paper all the species of the 

 subfamily are placed in the genus Sceliphron. To this and certain 

 other points of interpretation the writer can not agree; they will be 

 discussed in detail below. 



The present paper is in a sense supplementary to Dr. H. T. Fer- 

 nald's studies of the Sphecinae and Chlorinae, other subfamilies in 

 the family Sphecidae. Hearty thanks are hereby expressed to Doc- 

 tor Fernald for the active interest which he has taken in this study 

 and for assuming the responsibility for material loaned by a num- 

 ber of institutions and individuals. Thanks are also due to Guy C. 

 Crampton for helpful suggestions regarding the anatomy of the 

 group of insects under consideration, and to S. A. Rohwer for facili- 

 tating in every way possible the work of the writer at the National 

 Museum. 



1 1918, Kohl, Franz Priedricb. Die Hautflugler gruppe " Sphecinae," IV Tell, Die 

 naturliche Gattung Sceliphron Klug (PelopoUts) Latrielle. In der Annalen des Naturhis- 

 t«rlchen Hofmuseums Wien, vol. 32. 



No. 265.— Proceedings U. S. National Museum, Vol. 70. Art. I 



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