Ethyl methanesulphonate (0·75%) was mixed with food (1∶9) and fed to developing F1 (Oregon-K+/dumpy black cinnabar, dp b cn) individuals in second one-third part (54–86 h after egg deposition) of larval life, at 25±1°C, for inducing recombination in males ofDrosophila melanogaster. In control and 0·75% ethyl methanesulphonate experiments, pooled test cross progeny comprised 3475 and 13887 flies, respectively, out of which 9 and 236 were recombinants. From these, 9 and 192 recombinants were further test-crossed and 55·5% and 87·0% were verified, respectively. Non-reciprocal recombination was observed indp-b but not inb-cn region with 0·75% ethyl methanesulphonate as evidenced by high frequency of +b cn male recombinants over its complementary classdp ++. Majority of the +b cn male recombinants verified did not produce in their test cross progeny the two phenotypes (+b cn anddp b cn) in expected 1∶1 ratio contrary to +b cn female recombinants, suggesting influence of cytoplasm in transmission of recombinant (+b cn) phenotype from male.