species and taxonomy exam qs

Question 1

The scientists repeated their experiments, using female fruit flies as the visual stimulus.
When a male and female D. willistoni were together, their songs led to mating.
When two female D. willistoni were together, their songs did not lead to any attempt to
mate.
Use information from Figure 2 to suggest why the two females did not attempt to mate.

Answer 1

(Three) peaks (in pulse song) occur at the same time (since both female) / songs
identical / male peaks are different;
Accept suitable differences in male peaks eg number / length /
amplitude / interval
2. (Therefore) no male (song) to stimulate / cause mating;
OR
Nothing to stimulate / cause mating;