188 PROG. ENT. SOC. WASH., VOL. 20, NO. 9, DEC., 1918 



more, this species agrees with all the other characters of the 

 original description and with the parasitic habits mentioned in 

 Fauna Suecica. This fact, together with the evidence in the 

 Linnean collection, makes it certain that the species now known 

 as instigator was previously described by Linnaeus as compunctor. 

 The synonymy is therefore: 



Ephialtes compunctor (Linnaeus). 



Ichneumon compunctor Linnaeus, Nat. Syst. 10 Ed. 1758, p. 564, 



n. 31; Fauna Suec. 2 Ed., 1761, p. 403, n. 1609. 

 Ephialtes compunctor Schrank, Fauna Boica, vol. 2, pt. 3, 1802, 



p. 316. 

 Ichneumon instigator Fabricus, Ent. Syst., vol. 2, 1793, p. 164, 



no. 126. 

 Pimpla instigator Gravenhorst, Nov. acta acad. nat. Curios, vol. 



9, 1818, p. 291; Morley, Brit. Ichneumons 1908, vol. 3, p. 92. 

 The species which has heretofore gone under the name in- 

 stigator is a typical member of the genus Pimplidea Viereck 

 (= Pimpla Authors), and the following generic synonymy is 

 necessary. 



Ephialtes Schrank 1802 (not Gravenhorst 1829). 

 Syn. Pimplidea Viereck, 1914. 



The Gravenhorstian genus Ephialtes (1829) is synonymous and 

 isogenotypic with Ichneumon Linnaeus (1758) (See Viereck, Bui. 

 83, U. S. Nat. Mus., 1914), and must not be confused with 

 Ephialtes Schrank which is much older. 



DISTRICT OF COLUMBIA DIPTERA: TABANIDAE. 1 



BY W. L. McATEE AND W. R. WALTON. 



On account of the biting proclivities of most members of the 

 family, the Tabanidae, or horse-flies, are among the few groups of 

 insects that are recognized by the general public. Wherever the 

 biting species occur they are serious pests of wild mammals, 

 domestic stock, and sometimes even of man. African Tabanidae 

 transmit destructive diseases among mankind, but fortunately 

 so far as known American species have assumed no such role. 



Although the group is recognized by observers not versed in 

 entomology, its richness in species usually is entirely unsus- 

 pected. Ordinary estimates place the number of deer flies at one, 

 and of horse flies at two or three kinds. The facts are quite the 



1 For an account of the Syrphidae, sec Proc. Hiol. Soc. Wash. 29,1916, 

 pp. 173-203. 



