Figure 5

Inability of males to discriminate between sexes during mating behaviours. (A) Experimental design-1. After a certain time period over which male-male pseudo-copulation was observed (Step 1), the short-eyed male was replaced with the shortest-eyed female to continue the observation of mate choice (Step 2). N = 30. (B) Frequencies of mate choice of the intermediate-eyed male for each individual are indicated on each bar. (C) Experimental design-2. A fly group composed of three males (short, intermediate, and long eye spans) and two females (short and long eye spans) was prepared. In six fly groups, the intermediate males were focused on to observe their mate choice. (D) Average frequencies of mate choice of the intermediate males for each individual. The P values between individuals were 0.001 (long-eyed male vs. short-eyed male), 0.5 (long-eyed male vs. long-eyed female), and 0.1 (long-eyed female vs. short-eyed female). The illustrations in (A) and (C) were processed by Microsoft PowerPoint 2007 software (www.microsoft.com).