﻿SP.SBP'O 



THE ENTOMOLOGIST 



Vol. XLVIIL] JANUARY, 1915. FNo. 620 



ON THE HYBRIDS OF THE GENUS OPORABIA, 

 WITH SOME NOTES ON ITS MICROGENES. 



By J. W. H. Hakrison, B.Sc. 



The genus Oporabia is a very old group, and one which, 

 in spite of the fewness of the species included therein, it is 

 very difficult to understand. This difficulty arises from the 

 fact that, being hide-bound so to speak by the Linnean con- 

 ception of a species, students of the group are unable to decide 

 upon what constitutes a species within it. Grant the validity of 

 the Jordanian species, and the indecision vanishes. Jordan 

 looked upon each Linnean species as "une espece collective," 

 comprising within itself several " little species," or, as I call 

 them, " microgenes." Each of these microgenes will stand the 

 critical test of breeding true, and, in many cases, is differentiated 

 structurally — very slightly, of course — from its neighbours. I 

 have adopted the name "microgene" in preference to either 

 " subspecies " or " local race," because the labours of Fruhstor- 

 fer and others have reduced the name "subspecies" to represent 

 an entity of almost no value ; on the other hand, these micro- 

 genes are not local races in any sense of the word. Well-known 

 examples of genera, containing within their limits species with 

 hosts of microgenes, are the plant genera Hieracium, Rosa, 

 Ruhus and Mentha ; no one would dream either of calling Rubiis 

 argentatus a local race of R. friiticosus, or of recognising in 

 Rosa dumetorum a local race of R. canina. 



In my view the Linnean species Oporabia autumnata (Bkh.) 

 comprises, in this district, four microgenes. These are 0. 

 autumnata (sens, strict.), 0. alticolaria, 0. innivoraria and 

 0. fiUgrammaria. Similarly, locally, we find Oporabia dilutata 

 (Bkh.) containing three forms of the same value, viz. 0. dilutata 

 (sens, strict.), 0. fraxinaria and 0. christyi. The importance to 

 be attached to these forms has been hopelessly obscured in 

 the past, not only in this genus but also in other Lepidopterous 



ENTOM. JANUARY, 1915. B 



