THE GENETICS OF HABROBRACON JUGLANDIS ASHMEAD 



wings. The wasps are easily distinguishable. 

 The clipped females are sterile and the mutant 

 must be introduced through the males which are 

 of normal viability (Fig. 7). (Discarded) 



WST, wt (wings). This mutation occurred in the 

 summer of 1945 in the progeny of an X-rayed 

 female. In this mutation the raicrochaetae of 

 the primary wings are irregular in length, giv- 

 ing the wings a wet appearance. The females 

 are fully fertile, and the males are of normal 

 viability. 



Mutations for antennal length, structure, 

 and carriage have occurred in Habrobracon. 

 These factors may be found singly or in combi- 

 nation. Many of the genes cited in the present 

 work cause greater or less tendency toward an- 

 tennal deficiency; hov/ever, only those that show 

 marked deviations in antennal form are listed 

 as antennal mutants. 



DEFICIENCY, de (antennae and posterior extrem- 

 ity). In this mutant type the antennal seg- 

 ments may be irregularly fused. Failure of 

 normal development of structures at anterior or 

 at posterior extremities sometimes occurs. Ex- 

 ternal genitalia may be small or lacking, and 

 the digestive tract may fail to open posterior- 

 ly. No definite factors have been isolated for 

 these deficiencies; however, they have been 

 shown to be partially controlled by heredity 

 and to be highly correlated with age of mothers 

 (P. W. Whiting, 1926c). (Discarded) 



MINNESOTA YELLOW, My (base of antennae). In 

 August, 1929, wild-type stock from Minneapolis,^ 



54 



