84 



The Source of Variability 



Fig. 32. A comparison of the salient characters of the presumed hybrid 

 species Enjthroncura alicia and representatives of the two phylogenetic hnes 

 which were its probable parents. 



E. alicia combines the specialized, banded color pattern (D) of E. 

 trivittata with the style (A) and pygofer hook (C) of £. metopia; 

 its aedeagus (B) is somewhat intermediate between the presumed 

 parental types. The same type of mosaic mixtures of characters 

 occur in other species of Erythroneura and several species of mos- 

 quitoes thought to be of hybrid origin (Belkin and Hogue, 1959). 

 In spite of the genetic difficulties against hybridization between 

 well-separated species, viable hybrids between such parents occasion- 

 ally arise and produce a mixing of characters between phylogenetic 

 lines. In animals there is evidence indicating such a hybrid mixing 

 in the leafhopper genus Erythroneura. In the maculata group of this 

 genus four probable hybrids species have been detected, each be- 

 tween species belonging to different species complexes (Fig. 33) 

 (Ross 1958a). In the plants hybrid mixing has occurred in many 

 groups, most commonly perpetuated through the mechanism of 



