66 PROC. ENT. SOC. WASH., VOL. 20, NO. 3, MAR., 1918 



PROPACHYNEURON GIRAULT (HYMENOPTERA, CHALCIDOIDEA) . 



BY A. B. GAHAN, 



Bureau of Entomology, U. . Department of Agriculture. 



In Psyche, volume XXIV, 1917, p. 102, Mr. A. A. Girault has 

 proposed the new generic name Propachyneuron which he state 

 is "based on Encyrtus siphonophorae Ashmead of which Pachys 

 neuron micans Howard, P. aphidivorum Ashmead, and P. maida 

 phidis Ashmead are synonyms." 



It is evident from the material in the U. S. National Museum 

 that Ashmead's Encyrtus siphonophorae was a composite spe- 

 cies, the type series having included two species. The true 

 type is an Encyrtid and was correctly placed by Ashmead (Proc. 

 U. S. Nat. Mus. XXII, 1900, p. 399) in the genus Aphidencyrtus. 

 The author of the species, subsequent to the description, appar- 

 ently discovered that he had included more than one species among 

 the types and removed three of the specimens, one of which he 

 labelled Pachyneuron siphonophorae Ashmead but did not describe 

 the species. Mr. Girault evidently intended to base his genus 

 Propachy neuron on this manuscript species of Ashmead's, being 

 under the impression that these were the true types of Encyrtn* 

 siphonophorae. 



While Mr. Girault's intention is clear, he has named as type, of 

 his genus an apparently valid species entirely different from that 

 which he intended. This raises the complicated nomenclatorial 

 question whether the concept of a genus shall be determined by 

 the species named as type, regardless of the intention of the author, 

 or whether it shall follow the intention of the author. If the 

 former view is adhered to, as the writer believes it should be, then 

 Propachy neuron must fall as a synonym of Aphidencyrtus Ash- 

 mead. If the latter view is accepted then Propachy neuron will 

 have as . type Pachyneuron aphidivorum Ashmead, the oldest 

 synonym of P. siplionophorae Girault (not Ashmead.) 



In his description of Propachyneuron Girault says: "The snni;- 

 as Pachyneuron but the antennae bear three ring-joints." This is 

 true only of the female of aphidivorum. The male has a distinctly 

 6-jointed fimicle and two ring-joints. The other characters guv:: 

 by Girault for Propachyneuron are all duplicated in Pachyneuron. 

 It is the opinion of the writer, therefore, that the group, if it inny 

 even be called a group, is not deserving of a name. The genr'-ir 

 name Propachyneuron is, therefore, a synonym, whether of Aphi- 

 dencyrtus or Pachyneuron makes little difference. 



Date of Publication, September 27, 1918 



