Lymantria dispar (L.). A third reassessment

Abstract

In Lymantria dispar certain race crosses produce in the F 1 a marked excess of males as predicted by the Haldane 'rule'. On theoretical grounds we considered that in the F 2 and backcrosses involving these races the sex ratio should return more nearly to normal. This we found to be the case and the results support Haldane's view that the upset in the sex ratio in the F 1 is the result of genic imbalance. The race crosses studied are also used to provide further evidence against the Goldschmidt hypothesis that the excess of males is the result of transformation of females into males.