THE ENTOMOLOGIST. 



Vol. XVIL] SEPTEMBER, 1884. [No. 256. 



LYCjENA ARGIOLUS COMPARED WITH THE AMERICAN 

 LYC^NA PSEUDARGIOLUS. 



By J. Jenner Weir, F.L.S., F.Z.S., &c. 



In part xii., second series, of W. H. Edwards' ' Butterflies of 

 North America,' there is a most valuable contribution on that 

 singularly polymorphic species Lycana pseudargiolus of Boisduval 

 and Leconte. This insect is found as far north as 54°, and as 

 far south as Mexico. In response to its environment it has varied 

 exceedingly, and the different races have been regarded as distinct 

 species ; but Mr. Edwards has now arrived at the conclusion that 

 they " constitute one polymorphic species." 



I must refer the readers of this magazine to the work above 

 quoted for a complete account, but will shortly state some of the 

 main facts of the general history of the insect. 



Lyccena pseudargiolus varies according to the latitude and 

 longitude in which it is found, or in other words is topomorphic ; 

 according to the season of the emergence of the imago, horeo- 

 morphic ; and besides is dimorphic and trimorphic. A melanic 

 variety has also been developed ; two hermaphrodites are figured, 

 and two heteromorphic forms. 



1. In the high boreal regions the species is one-brooded and 

 dimorphic, — L. lucia, Kirby, and L. violacea, Edw. 



2. At about lat. 45° it becomes double-brooded, the second 

 emergence being L. neglecta, Edw. ; and the spring emergence 

 has become trimorphic by the development of an intermediate 

 form, L. marginata, Edw., between L. lucia and L. violacea. 



ENTOM. — SEPT., 1884. 2 C 



