GENETIC EVIDENCE FOR DIPLOID MALES IN 



HABROBRACON.^ 



ANNA R. WHITING, 

 BUSSEY INSTITUTION, HARVARD UNIVERSITY. 



The production of males from fertilized eggs in the parasitic 

 wasp, Habrobrocon juglandis (Ashmead), is discussed in a previ- 

 ous paper (Whiting, Anna R., 1925). It was shown that homo- 

 zygous orange-eyed females, when crossed to related males with 

 dominant black eyes, produced a few practically sterile black- 

 eyed sons, in addition to the usual number of impaternate orange- 

 eyed males and heterozygous black-eyed daughters. The few 

 daughters of these " patroclinous " or biparental males were black- 

 eyed, almost completely sterile and in many cases abnormal in ap- 

 pearance. It was postulated that a spermatozoon developing in- 

 dependently in the egg cytoplasm and crowding out the egg nu- 

 cleus might produce a male which, although resembling its diploid 

 sisters, would be haploid. This did not explain why recessive 

 males failed to appear in broods from the reciprocal cross of 

 homozygous black females by orange males ; neither did it throw 

 any light on the sterility of the biparental males and of their few 

 daughters. 



With the occurrence of new mutations additional facts have 

 been brought out consistent with previous results and throwing 

 further light upon the problem. 



A series of quadruple allelomorphs affecting eye color (Whit- 

 ing, Anna R. and Burton, Raymond H., 1926) has been used in 

 various combinations in breeding experiments to be discussed. 

 These are black (O), light (o 1 ), orange (o), and ivory (o 1 ), in 

 decreasing order of dominance. In black, orange, and ivory the 

 ocelli are of the same color as the compound eyes. In light, they 

 are gray while the compound eyes remain black. Distinction from 



1 The author is indebted to Bussey Institution, Harvard University, for 

 the use of space and equipment, and to the Committee for Research in Prob- 

 lems of Sex of the National Research Council for financial aid in carrying 

 on this work. 



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