THE GENETICS OF HABROBRACON JUGLANDIS ASHMEAD 



together. No marked disproportion appears in 

 the reduction of the size of the legs. Minia- 

 ture is a serailethal. Many die as pupae. Adult 

 males are of good fertility, but adult females 

 are almost sterile. (Discarded) 



BROAD, br (thorax). In August, 1930, a number 

 of males were found with thorax abnormally 

 broadened. There is some tendency toward re- 

 duplication in the wings. The mutant type was 

 first noticed in about 50 per cent of the sons 

 of two different sisters. The character is 

 somewhat irregular, and it cannot be stated 

 with certainty that this represents the first 

 appearance of the mutation (P. W. Whiting, 

 1932a). Broad may be called an irregular re- 

 cessive, but about 50 per cent of the heterozy- 

 gous females show the trait to a slight extent. 

 Broad has good fertility and viability. (Dis- 

 carded) 



SMALL-HEAD, sh (head). This appeared in the 

 progeny of a mated female that had been X-rayed 

 (P. W. Whiting, 1929b). Wasps exhibiting this^ 

 mutation have very small heads. The mutant 

 type is much more distinct in the homozygous^ 

 females and shows considerable overlapping in 

 the males. It is of good fertility and viabil- 

 ity. (Discarded) 



EXTENDED-HEAD, Eh (prothorax). In July, 1931, 

 an X-rayed mated wild-type female (dosage about 

 3840 R units) produced in her progeny one male 

 with an extended head, which proved to be a 

 dominant mutation (N. C. Bostian, 1931). In 

 this mutant type, the membrane dorsal to the 



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