Homozygotes have a vg wing phenotype. Postscutellars and halteres are missing. vg82c13/vg83b27 transheterozygotes have wild-type halteres and postscutellars.
homozygous wing phenotype like that of vg halteres absent postscutellar bristles absent homozygous viable female-fertile?
"irradiation" was stated as tentative. "spontaneous" was stated as tentative.