INHERITANCE OF WING COLOUR IN 

 LEPIDOPTERA. 



IV. MELANISM IN BOARMIA ABIETARIA. 



By H. ONSLOW. 



(With Plate VI.) 



The inheritance of melanism has already been described in two 

 insects closely related to B. ahietaria, namely Tephrosia consonaria^ and 

 Boarmia consortaria^. 



These three insects have scarcely ever been taken north of London, 

 being almost exclusively confined to Kent and Surrey, where another 

 melanic variety, that of Tephrosia extersaria (luridata), has lately made 

 its appearance. They are thus contrasted with most melanic varieties, 

 which generally come fi-om the Black Country, or other urban districts. 

 A melanic race of B. consortaria has, however, recently appeared in 

 Warwickshire. 



The melanic variety of B. ahietaria seems never to have been named, 

 for sericearia Curt, is apparently meant to apply to a dark form of the 

 type, somewhat similar to figs. 1 and 2 of Plate VI. There are no 

 tecords of any extensive breeding experiments, but Bower^ exhibited a 

 family of 17 insects bred fi-om ova deposited by a type ^, which had 

 been captured. The cT appears to have been a melanic, for 7 of the 

 ofiFspring were melanic and 10 type. .Stallman* also reared a series of 

 insects bred from a melanic $ x a type cT, which contained no type, 

 but were " all dark to black." These results appear to be in agreement 

 with the conclusion arrived at in this note, namely that the melanic 

 variety behaves as a simple Mendelian dominant to the type form. 



> Onslow, H., Journ. of Genetics, Vol. ix, No. 1, p. 53, Dec. 1919. 

 - Onslow, H., Journ. of Genetics, Vol. ix, No. 4, p. 339, Mar. 1920. 

 » Bower, B. A., Ent. Rec, Vol. xi, p. 82, 1899. 

 * Stallman, Ent. Rec, Vol. xxviii, p. 21, 1916. 



