NEW FOEMS OF SPHECOID WASPS OF THE GENUS 

 DIDINEIS WESMAEL 



By J. E. Malloch 



Biologist, Bureau of the Biological Survey 

 and 



S. A. EOHWER 



Assistant Chief, Plant Quarantine and Control ACLmvnistration, Department of 



Agriculture 



The present paper contains a revision of the North American 

 species of the genus Didineis Wesmael, with descriptions of two new 

 species and one new variety. 



Genus DIDINEIS Wesmael 



Didineis Wesmael, Revue Critique, 1851, p. 96. — Kohl, Ann. li. k. Hofmus. Wien, 

 vol. 11, 1896, p. 402.— Fox, Ent. News, vol. 5, 1894, p. 126. 



Kolil considers the genus Didineis as a subgenus of Alyson Jurine, 

 but with the striking differences in the venation of the fore and 

 hind wings (figs. 1, 2), together with the differences that seem to 

 exist in the genitalia (figs. 3, 4), it would be desirable to recognize 

 it as a genus, which has been done by many European and most 

 American workers. 



Fox tabulated the American species in 1894. Since that time 

 three new species have been described, and in the collections of 

 the United States National Museum there are representatives of two 

 additional new species and a new variety. To make it easier to rec- 

 ognize these forms we have prepared the following key, which 

 includes all the North American species; but the species marked 

 with an asterisk is placed entirely on description. 



KEY TO THE NORTH AMERICAN SPECIES OP DIDINEIS 



1. Females 2. 



Males 6. 



2. Thorax and abdomen reddish-brown 3. 



Thorax and part of the abdomen black 4 



3. Head black stevensi Rohwer, 



Head pale peculiaris Fox. 



4. Apical tergites black *sanctacrucae Bi'adley. 



Abdomen entirely rufous 5, 



No. 2837.— Proceedings U. S. National Museum, Vol. 77. Art. 14 



2599 — 30 1 



