Figure 2From: Hybrid male sterility between Drosophila willistoni species is caused by male failure to transfer sperm during copulationAverage proportion of sperm in female storage at 5 (dark grey) and 9 (light grey) minute interrupted copulations for both conspecific D. w. quechua (Q) and D. w. willistoni (W) matings. Error bars are ± 1 standard error; Numbers within bars (N) are the number of females sampled.Back to article page