PROG. ENT. SOC. WASH., VOL. 20, NO. 4, APR., 1918 83 



Neodiprion, new genus. 



All of the Nearctic species which have heretofore been called 

 Lophyrus or Diprion can easily be distinguished from the old 

 world species (except sertifer, which belongs to Neodiprion s. s.) 

 by the shape, size and sculpture of the metascutellum. This 

 character is of considerable importance and the writer makes use 

 of it in erecting the genus Neodiprion. The genus Neodiprion 

 is the only native Diprinoid group in which the anal cells are 

 separated by a short straight vein and it replaces the names 

 Lophyrus and Diprion for the native species. 



The genus Neodiprion contains two well defined and easily 

 recognized groups which are worthy of name and are here treated 

 as subgenera. These may be separated by the following key: 



Key to the Subgenera of Neodiprion Rohwer. 



1. Large robust species with the tergum banded ( females) or spotted 

 (males) with yellow; apical six antennal joints of male unira- 

 mose; postocellar line of female much less than ocelloccipital 

 line; calcarium of female robust somewhat clavate apically. 



Zadiprion Rohwer 



Small or medium sized species with tergum unicolorous except for 

 a pale lateral band in some females; antennae of male biramose 

 to apex; postocellar line of female equal to or shorter than t'he 

 ocelloccipital line; calcarium of female normal. .Neodiprion Rohwer 



Zadiprion, new subgenus. 



Genotype. Diprion grandis Rohwer. 



Superficially this group of large species resembes the species 

 of the genus Diprion and in some ways it seems to be intermediate 

 between Diprion and Neodiprion. 



The species of this subgenus are known only from the arid 

 western part of the United States and the northern part of 

 Mexico. The females may be separated by the following key: 



Key to the species of Zadiprion 



1. Emargination of the last sternite about one-half as deep as wide. 



(scutellun yellow with large separated punctures; antennae 



twenty-two-jointed) townsendi (Cockerell) 



Emargination of the last sternite not a fourth as deep as wide 2 



2. Scutellum yellow, except the posterior margin nearly impunctate; 



basal plates yellow '. grandis (Rohwer) 



Scutellum piceous and ferruginous, coarsely and closely punc- 

 tured; basal plates piceous raUicola Rohwer 



