THE GENETICS OF HABROBRACON JUGLANDIS ASHMEAD 



ivory, and hence the mutation took, place in 

 spermatogenesis involving at least one sperm. 

 Light-ocelli has black eyes but ocelli are very 

 light in compound v/ith ivory or with orange. 

 In pure light stock the ocelli may be charac- 

 terized as light brown, somewhat darker in the 

 males. It was found to be recessive to type 

 and, as regards compound eyes, dominant to 

 orange and to ivory. In combination with orange 

 or ivory the ocelli were lighter than in the 

 homozygous condition. Light-ocelli was lost 

 before the appearance of a fifth allele, dahlia, 

 and, therefore, was never tested v/ith that or 

 v;ith any eye colors found later. 



DAHLIA, 0^ (eyes). The fifth allele in the 

 orange locus appeared December 1, 1929, from a 

 cross of an ivory female by a wild-type male. 

 A single female with light ocelli and eyes very 

 dark reddish-brown appeared. This mutant, called 

 dahlia, proved to be dominant to orange and to 

 ivory although somewhat lightened in combina- 

 tion with either. In view of decreasing domi- 

 nance associated with decreasing pigmentation 

 in this series, it is probable that light-ocelli 

 vmuld have come between wild-type and dahlia, 

 could it have been tested. 



The locus, orange, appears to be especially 

 unstable, but there is certainly no striking 

 increase of mutability correlated with X-ray 

 treatment (P. W. Whiting, 1932a). P. W. Whiting 

 (1928b) reported a very high correlation be- 

 tween mosaicism and apparent mutation for this 

 locus. The orange series is female fertile 

 with good viability of both males and females. 

 These stocks, except for light-ocelli, are be- 



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