GENETIC EVIDENCE FOR DIPLOID MALES INHABROBRACON

Abstract

1. Four allelomorphs affecting eye color and three pairs of allelomorphs affecting wing form and venation, none linked, are studied from the point of view of the method of their inheritance by biparental males in Habrobracon juglandis (Ashmead). 2. A female homozygous for one or more recessive factors when crossed to a male carrying allelomorphs to these factors produces, in addition to recessive haploid sons and dominant diploid daughters, sons which have all dominant characters like their sisters. 3. In crosses where females are homozygous for some recessive and some dominant factors and males possess allelomorphs the biparental sons are entirely dominant, showing that they have some factors from each parent. 4. When three of these factors affect one structure (the wing in this case) if one recessive and two dominants are contributed by one parent, their allelomorphs by the other, this structure in biparental males shows all the dominant characters. 5. From these results it is concluded that biparental males are diploid (Whiting, P. W. and Whiting, Anna R., 1925) at least for the four chromosomes that can be identified genetically. 6. Biparental males and their daughters are often abnormal in appearance and usually sterile or nearly so. When fertile they breed as dominants (with one, and possibly two, exceptions noted above).